Power Integrations, Inc. Patent applications |
Patent application number | Title | Published |
20150333764 | DIGITAL-TO-ANALOG CONVERTER CIRCUIT FOR USE IN A POWER CONVERTER - A digital-to-analog converter circuit includes an input to receive a digital input signal having multiple bits. A modulation circuit is coupled to respond to less significant bits of the digital input signal by outputting a modulation signal that alternates between a logic low level and a logic high level. A digital-to-analog circuit is configured to convert more significant bits of the digital input signal to a first analog level. The digital-to-analog circuit is configured to alternate an analog output between the first analog level corresponding to a value of the more significant bits and a second analog level corresponding to one of adjacent values of the more significant bits in response to the modulation signal. | 11-19-2015 |
20150333630 | MULTI-PACE CONTROLLER - A controller for controlling a power supply includes a feedback signal generator to generate a feedback signal representative of an output current in response to an output sense signal. A state selector circuit receives the feedback signal and outputs a digital state signal to set an operational state of a switch of the power supply. The state selector circuit adjusts the digital state signal in response to feedback information at an end of a feedback period. A driver circuit receives the digital state signal and generates a drive signal in response to the digital state signal. The drive signal drives switching of the switch in accordance with the operational state of the switch. | 11-19-2015 |
20150326008 | FAULT PROTECTION CIRCUIT - A fault detection circuit for use with a power converter includes an initiate fault check circuit coupled to generate an enable signal in response to a first sense signal coupled to be received from an output socket. A threshold detection circuit is coupled to generate a threshold detection output signal in response to a second sense signal coupled to be received from the power converter and a second reference signal. A logic circuit is coupled to generate a fault signal that is coupled to be received by the power converter in response to the threshold detection output signal and the enable signal. | 11-12-2015 |
20150312978 | MULTI-BLEEDER MODE CONTROL FOR IMPROVED LED DRIVER PERFORMANCE - Various examples directed to phase-dimming LED driver input circuitry having multiple bleeder circuits activated by a controller with multi-bleeder mode control are disclosed. In one example, the input circuitry may include multiple bleeder circuits controlled by the controller in an open-loop or closed-loop configuration. The controller may selectively activate or deactivate the multiple bleeder circuits based on the input line voltage, the dimming state, and the type of dimming being implemented to improve performance of the LED driver by preventing or reducing shimmering/blinking and by reducing bleeder loss. | 10-29-2015 |
20150303812 | DIMMING EDGE DETECTION FOR POWER CONVERTER - A controller for a power converter includes an edge detection circuit and a drive circuit. The edge detection circuit includes a comparator, a count module, and an edge checking module. The comparator is coupled to output a compare signal in response to comparing an input sense signal and a count signal. The input sense signal is representative of an input voltage of the power converter. The count module is coupled to adjust the count signal to track the input sense signal in response to receiving the compare signal. The edge checking module is coupled to output at least one edge signal in response to the compare signal. The drive circuit is coupled to output a drive signal in response to the at least one edge signal. The drive signal is for controlling a switch coupled to regulate an output of the power converter. | 10-22-2015 |
20150295500 | SAMPLING FOR DIMMER EDGE DETECTION IN POWER CONVERTER - A controller and a method for controlling a power converter includes a sample block coupled to generate a first, second, and third sample by sampling an input sense signal that is representative of an input voltage of the power converter. An enable signal is asserted when a first difference between the first sample and the second sample exceeds a first threshold. An edge signal is asserted when both the enable signal is asserted and a second difference between the first sample and the third sample exceeds a second threshold. A drive circuit is coupled to output a drive signal in response to the edge signal. The drive signal is for controlling a switch coupled to regulate an output of the power converter. | 10-15-2015 |
20150200599 | VARIABLE FEEDBACK SIGNAL BASED ON CONDUCTION TIME - A controller for a power converter includes conduction detection circuitry and a variable reference generator. The conduction detection circuitry is coupled to generate a conduction signal representative of conduction times that an input signal is above a threshold value. The variable reference generator is coupled to receive the conduction signal and configured to generate a count value in response to a first conduction time of the conduction signal. The variable reference generator is coupled to output a reference signal in response to the count value and in response to prior count values stored in the variable reference generator. | 07-16-2015 |
20150078050 | DIGITAL PEAK DETECTOR WITH FOLLOWER MODE - Circuits and processes for detecting a peak value of an input signal are disclosed. In one example, a peak detector circuit may sample a line sense signal, determine the peak value of the line sense signal during a search window, and output a peak detection signal representative of the determined peak value. In a first mode, the peak detector circuit may cause the peak detection signal to be representative of the determined peak value from an immediately preceding search window. In a second mode, the peak detector circuit may cause the peak detection signal to follow the sampled line sense signal. The peak detector circuit may operate in the second mode in response to the sample of the line sense signal being greater than a peak value of the line sense signal from an immediately preceding search window by more than a threshold amount. | 03-19-2015 |
20150070953 | WAVEFORM SHAPE DISCRIMINATOR - A waveform shape discriminator includes a running maximum finder circuit coupled to receive a sense signal. The running maximum finder circuit is coupled to update a running maximum signal in response to the sense signal. A first comparator is coupled to receive the sense signal and a running maximum threshold signal that is representative of the running maximum signal. A search window block is coupled to receive the input signal to detect a search window in the sense signal. An output circuit is coupled to an output of the first comparator and an output of the search window block to determine a presence of a waveform shape in the sense signal within the search window in the sense signal. | 03-12-2015 |
20150062985 | PRE-DISTORTION OF SENSED CURRENT IN A POWER FACTOR CORRECTION CIRCUIT - An example controller includes a power factor enhancer, an on-time controller, and a switching signal generator. The power factor enhancer is coupled to generate a pre-distortion signal each half-line cycle of an ac input voltage of a PFC converter. The on-time controller ends an on-time of a PFC switch in response to a sensed PFC switch current of the PFC converter multiplied by the pre-distortion signal. The switching signal generator controls an input current waveform of the PFC converter to substantially follow a shape of an input voltage waveform by generating a switching signal in response to the on-time controller to control switching of the PFC switch. The power factor enhancer adjusts the pre-distortion signal to pre-distort the sensed PFC switch current to compensate for distortion in the input current waveform. | 03-05-2015 |
20150062974 | Controller IC with Zero-Crossing Detector and Capacitor Discharge Switching Element - An integrated circuit (IC) for controlling the discharge of a capacitor coupled across first and second input terminals of a power converter circuit, wherein the first and second terminals for receiving an ac line voltage. The IC includes a switching element coupled across the first and second input terminals and a detector circuit. The detector circuit including first and second comparators that produce first and second output signals responsive to a zero-crossing event of the ac line voltage. The first and second output signals being used to generate a reset signal coupled to a timer circuit responsive to the zero-crossing event. When the reset signal is not received within a delay time period, the timer circuit outputs a discharge signal that turns the switching element on, thereby discharging the capacitor. | 03-05-2015 |
20150062768 | FEEDBACK PROTECTION FROM ADJACENT TERMINAL SHORTS - This relates to detecting unwanted couplings between a protected terminal and an adjacent terminal of an IC controller of a power supply. The voltages across adjacent terminals are monitored. If the voltage difference between the terminals falls below a minimum threshold for greater than a first duration of time, an internal current source injects current into one of the terminals. If, within a second duration of time, the injected current pulls the voltage of the injected terminal to a voltage that causes the voltage difference between the terminals to be above the minimum threshold, it may be determined that a transient fault has occurred and been cleared or falsely detected. If, however, the injected current does not pull the voltage of the injected terminal to a voltage that causes the voltage between the adjacent terminals to be above the minimum threshold, the fault condition is confirmed and switching is disabled. | 03-05-2015 |
20150035597 | OPERATIONAL AMPLIFIER WITH SELECTIVE INPUT - An operational amplifier includes a selective differential stage including a first current mirror and a current distribution circuit. First and second legs of the first current mirror are responsive to current in first and second paths of the current distribution circuit, which distributes a tail current in response to a first signal received by a first input of the operational amplifier. Current in a first path of a selection circuit in the second path of the current distribution circuit is responsive to a second signal received by a second input of the operational amplifier. Current in the second path of the selection circuit is responsive to a third signal received by a third input of the operational amplifier. An output stage generates an output signal responsive to a difference between the first signal and one of the second and third signals. | 02-05-2015 |
20140374768 | HIGH QUALITY GAN HIGH-VOLTAGE HFETS ON SILICON - Substrates of GaN over silicon suitable for forming electronics devices such as heterostructure field effect transistors (HFETs), and methods of making the substrates, are disclosed. Voids in a crystalline Al | 12-25-2014 |
20140333228 | DIMMER DETECTOR FOR BLEEDER CIRCUIT ACTIVATION - A circuit to be utilized for an LED driver bleeder activation. The circuit comprises a circuit block for timing a duration of any removed portion of a rectified line signal. The input of the circuit to be coupled to receive the phase controlled rectified line signal through a voltage divider. Comparing the divided rectified line signal with a threshold voltage and output a comparison result. A timer coupled to the comparator and responsive to the comparison result to time the duration of the removed portion of the rectified line signal and activate the bleeder activation circuitry to turn on the switching element of the bleeder to sink a controlled current from the input line. | 11-13-2014 |
20140320075 | USB CHARGING WITH DATA COMMUNICATION - A process is disclosed for communicating digital data between a powered device and a charging device via a universal serial bus (USB). The process includes conducting a handshaking period between the powered device and the charging device via the USB. The powered device initiates a mode of normal operation of the charging device after an end of the handshaking period. The charging device communicates digital data (e.g., available power levels) between the powered device and the charging device during a time period that starts with the end of the handshaking period and ends with a beginning of the mode of normal operation. | 10-30-2014 |
20140268951 | LOAD-SELECTIVE INPUT VOLTAGE SENSOR - A power converter controller includes a switch driver circuit coupled to generate a drive signal to control switching of a power switch to control a transfer of energy from an input of the power converter to an output of the power converter. An input sense circuit is coupled to receive an input sense signal representative of the input of a power converter. A sense enable circuit is coupled to receive the drive signal to generate a sense enable signal to control the input sense circuit in response to the drive signal. The sense enable signal is coupled to control the input sense circuit to sense the input sense signal continuously in response to a first load condition, and sense the input sense signal only during a fraction of a switching period of the power switch in response to a second load condition. | 09-18-2014 |
20140268922 | SWITCHED MODE POWER CONVERTER CONTROLLER WITH RAMP TIME MODULATION - A controller for use in a power converter includes a drive circuit coupled to generate a drive signal to control switching of a power switch to control a transfer of energy from a power converter input to a power converter output. The controller also includes an input for receiving an enable signal including enable events responsive to the power converter output. The drive circuit is coupled to turn ON the power switch in response to the enable events and turn OFF the power switch in response to a power switch current reaching a current limit threshold. A current limit threshold generator is coupled to receive the drive signal from the enable events of the enable signal. The current limit threshold may be a ramp signal and the ramp signal along with the time between enable events may be used to modulate the drive signal. | 09-18-2014 |
20140266284 | ISOLATION TESTING OF SEMICONDUCTOR DEVICES - Methods and apparatus for isolation testing of semiconductor devices are disclosed. One example apparatus may include an interface portion for making electrical contact with packaged semiconductor devices under test. The interface portion may include an insulating support configured and dimensioned to support multiple semiconductor device packages, each semiconductor device package having a plurality of electrical contacts. The interface portion may further include a first electrically conductive surface to electrically contact a first proper subset of the plurality of electrical contacts of each of the semiconductor device packages supported by the interface portion and a second electrically conductive surface to electrically contact a second proper subset of the plurality of electrical contacts of each of the semiconductor device packages supported by the insulating support. | 09-18-2014 |
20140265898 | LOSSLESS PRELOAD FOR LED DRIVER WITH EXTENDED DIMMING - A quasi-phase active preload circuit to be coupled at the output of a non-isolated LED driver converter having a pre-stage phase-angle control dimmer circuit, such as a commonly used leading-edge control Triac dimmer, is disclosed. The quasi-phase active preload circuit may include a preload resistor coupled to a current-controlled current source configured to draw a sinking current through the preload resistor based on a peak detect signal. The peak detect signal may be, in one example, representative of a leading-edge peak voltage of an output of the Triac dimmer circuit, which may be representative of a conduction angle of the Triac dimmer circuit. During normal operating conditions, no sinking current is drawn through the preload resistor. During low dimming conditions, a sinking current that is responsive to the peak detect signal is drawn through the preload resistor. During deep dimming or when used with a leaky Triac dimmer, a maximum sinking current may be drawn through the preload resistor by the current-controlled current source. | 09-18-2014 |
20140265896 | LIGHT DRIVER CONTROL SYSTEM - A system for controlling a light source includes a control circuit to be coupled to an ac source to receive an ac signal. The control circuit includes an input controller coupled to receive an input control signal and dimming command circuitry coupled to the input controller and coupled to receive the ac signal. The dimming command circuitry is coupled to remove one or more portions of a predetermined duration from the ac signal followed by a substantially full ac signal in response to the input control signal. A lighting driver circuit is to be coupled to a light source and coupled to receive the ac signal from the control circuit. The lighting driver circuit is coupled to drive the light source to have a light output adjusted in response to the removed one or more portions of the predetermined duration from the ac signal by the dimming command circuitry. | 09-18-2014 |
20140265861 | CURRENT LIMITER WITH ACTIVE DAMPING - This relates to a current limiter circuit that can be used in a power conversion system having a triac dimmer. In one example, the power conversion system may be used in an off-line LED driver. The current limiter circuit may be coupled to a power converter of the power conversion system and may operate to reduce the current that the power converter receives from an input line in the event of a power line surge. The current limiter circuit may also be coupled to the triac dimmer and may also operate as a damper for a portion of the half line cycle. The current limiter circuit may dampen the ringing in the triac current for a portion of the half line cycle and may cease dampening for the remaining portion of the half line cycle. | 09-18-2014 |
20140264952 | SUPPLEMENTING WIRE BONDS - Systems and techniques for supplementing wire bonds. In one embodiment, a device includes a body having a first surface, a first wire bond pad disposed on the first surface, a first wire that is wire bonded to the first wire bond pad to form a contact between the first wire and the first wire bond pad, a first supplemental conductor disposed to form a supplemental conduit between the first wire and the first wire bond pad, a second wire bond pad disposed on the first surface, a second wire that is wire bonded to the second wire bond pad to form a contact between the second wire and the second wire bond pad, and a second supplemental conductor disposed to form a supplemental conduit between the second wire and the second wire bond pad. The first supplemental conductor is discrete from the second supplemental conductor. | 09-18-2014 |
20140254214 | TECHNIQUES FOR CONTROLLING A POWER CONVERTER USING MULTIPLE CONTROLLERS - A power converter controller includes a primary controller that is galvanically isolated from a secondary controller. The primary controller controls a state of a power switch during a first mode of operation according to a switching pattern defined by the primary controller. During a second mode of operation, the primary controller controls the state of the power switch in response to control signals received via a communication link. The secondary controller operates in a powered down state during the first mode of operation. The secondary controller initiates a transition operation with the primary controller that transitions the primary controller and the secondary controller from the first mode of operation to the second mode of operation. In the second mode of operation, the secondary controller transmit the control signals to the primary controller via the communication link. | 09-11-2014 |
20140254213 | POWER CONVERTER OUTPUT VOLTAGE CLAMP AND SUPPLY TERMINAL - A secondary control circuit includes a voltage regulator circuit to be coupled to an output of a power converter to provide a regulated power supply. One or more switched loads is coupled between a first terminal to be coupled to the output of the power converter and an output ground terminal. One or more comparator circuits is coupled to a second terminal coupled to receive an output sense signal. Each one of the one or more comparator circuits is coupled to receive a respective one of one or more reference signals. Each respective one of the one or more reference signals is a scaled representation of a first one of the one or more reference signals. Each one of the one or more switched loads is coupled to be switched in response to an output of a respective one of the one or more comparator circuits. | 09-11-2014 |
20140254212 | POWER CONVERTER USING MULTIPLE CONTROLLERS - A power converter controller includes a primary controller and a secondary controller. The primary controller is coupled to receive one or more request signals from the secondary controller and transition a power switch from an OFF state to an ON state in response to each of the received request signals. The primary controller is coupled to detect a turn-off condition when the power switch is in the ON state and transition the power switch from the ON state to the OFF state in response to detection of the turn-off condition. The secondary controller is galvanically isolated from the primary controller. The secondary controller is coupled to transmit the request signals to the primary controller and control the amount of time between the transmission of each of the request signals. | 09-11-2014 |
20140254202 | LOW THRESHOLD VOLTAGE COMPARATOR - A voltage comparator includes an amplifier coupled to receive an input signal at an amplifier input and generate an output signal at an amplifier output in response to the input signal. The amplifier includes a current generation circuit coupled to generate a first current flowing through a first branch and a second current flowing through a second branch. A first transistor has a first terminal coupled to the amplifier input and a second terminal coupled to the first branch. A second transistor has a third terminal coupled to the second branch, a fourth terminal coupled to a reference voltage. A second control terminal of the second transistor is coupled to the first control terminal. An output circuit is coupled to the amplifier output to generate a comparator output signal in response to the output signal. The amplifier output is coupled to the second branch. | 09-11-2014 |
20140247628 | METHOD AND APPARATUS FOR POWER CONVERTER FAULT CONDITION DETECTION - A controller includes a control, a sensor, and a fault detector. The control is configured to control a switch to regulate an output of the power converter. The sensor receives a signal from a terminal of the controller that is representative of an input voltage during an ON state of the switch and is representative of an output voltage during an OFF state of the switch. The sensor is configured to sample the signal from the terminal during the ON state to generate a first sample signal and to sample the signal from the terminal during the OFF state to generate a second sample signal. The fault detector detects a fault condition in response to either the first or the second sample signals. The control inhibits the switching of the switch to reduce a power output level of the power converter in response to the fault condition. | 09-04-2014 |
20140239849 | BLEEDER CIRCUIT HAVING CURRENT SENSE WITH EDGE DETECTION - A bleeder circuit for use in a power converter of a lighting system includes a current sense circuit coupled between first and second terminals of an input of a driver circuit to be coupled to drive a load. The current sense circuit is coupled to output a current sense signal in response to an input current through an input of the power converter coupled to the input of the driver circuit. An edge detection circuit is coupled between the first and second terminals to output an edge detection signal in response to an input signal between the first and second terminals. A variable current circuit is coupled between the first and second terminals to conduct a bleeder current between the first and second terminals in response to current sense signal and further in response to the edge detection signal. | 08-28-2014 |
20140239309 | Heterostructure Power Transistor With AlSiN Passivation Layer - A heterostructure semiconductor device includes a first active layer and a second active layer disposed on the first active layer. A two-dimensional electron gas layer is formed between the first and second active layers. An AlSiN passivation layer is disposed on the second active layer. First and second ohmic contacts electrically connect to the second active layer. The first and second ohmic contacts are laterally spaced-apart, with a gate being disposed between the first and second ohmic contacts. | 08-28-2014 |
20140233274 | POWER SUPPLY CONTROLLER WITH MINIMUM-SUM MULTI-CYCLE MODULATION - An example power supply controller includes a signal separator circuit that generates a feedback signal. An error signal generator generates an error signal in response to the feedback signal. A control circuit generates a drive signal in response to the error signal. The drive signal controls switching of a switch. A multi-cycle modulation circuit is included in the control circuit and generates a skip signal in response to a start skip signal, a stop skip signal and a skip mask signal. The skip mask signal is generated in response to the skip signal. The start skip and stop skip signals cause the drive signal to start skipping or stop skipping, respectively, on-time intervals of cycles. The skip mask signal disables the start skip signal from causing the drive signal to start skipping the on-time intervals of cycles. | 08-21-2014 |
20140211516 | METHOD AND APPARATUS FOR INPUT CHARGE CONTROL OF A POWER SUPPLY - An example method of controlling a power supply to have a constant current output includes receiving an input current sense signal, an input voltage sense signal, and an output voltage sense signal. A control signal is then generated to control switching of a switch of the power supply to regulate an output current of the power supply. The generating of the control signal includes integrating the input current sense signal during a switching period of the control signal to generate an integrated signal representative of a charge taken from an input voltage source of the power supply. Generating the control signal also includes controlling the switching of the switch such that the integrated signal is proportional to a ratio of the output voltage sense signal to the input voltage sense signal. | 07-31-2014 |
20140210446 | METHOD AND APPARATUS FOR IMPLEMENTING SLEW RATE CONTROL USING BYPASS CAPACITOR - An example circuit includes a capacitance circuit, a regulator circuit, and a slew rate control circuit. The capacitance circuit is coupled between a first node and a second node. The regulator circuit is coupled to the capacitance circuit to regulate a supply voltage across the capacitance circuit with a charge current during a normal operation mode of the circuit. The slew rate control circuit is coupled to the capacitance circuit and the regulator circuit. The slew rate control circuit is coupled to lower a slew rate of a change in voltage over change in time between the first and second nodes during a power up mode of the circuit. The slew rate control circuit includes a transistor coupled between the first and second nodes to shunt excess current from the charge current. | 07-31-2014 |
20140204628 | MULTI-STAGE SAMPLING CIRCUIT FOR A POWER CONVERTER CONTROLLER - An example controller for a power converter includes a track and hold circuit, a sample and hold circuit, and drive logic. The track and hold circuit receives a signal that is representative of an output voltage of the power converter. The track and hold circuit includes a first capacitor that provides a first voltage that tracks the signal and then holds the first voltage. The sample and hold circuit then samples the first voltage that is held on the first capacitor. The sample and hold circuit includes a second capacitor that holds a second voltage representative of the first voltage after a fixed sample period. The second capacitor is larger than that of the first capacitor. The drive logic controlling the first switch to regulate the output of the power converter includes disabling the first switch during an on time of the first switch responsive to the second voltage. | 07-24-2014 |
20140204626 | RECEIVE CIRCUIT FOR USE IN A POWER CONVERTER - A receive circuit for use in a power converter controller includes a first amplifier coupled to receive an input pulse. A second amplifier is coupled to a first output of the first amplifier. The first output is coupled to be responsive to the input pulse and to a second output of the second amplifier. An output circuit is coupled to generate an output signal in response to the second output. | 07-24-2014 |
20140204625 | SECONDARY CONTROLLER FOR USE IN SYNCHRONOUS FLYBACK CONVERTER - A secondary controller for use in a synchronous flyback converter includes a comparator, a drive circuit, and logic circuitry. The comparator is coupled to generate a compare signal in response to a comparison of a threshold to an input signal representative of a secondary winding voltage of the synchronous flyback converter. The drive circuit is coupled to generate a drive signal to control a first switch to be coupled to a primary side of the synchronous flyback converter. The drive signal is coupled to be generated by the drive circuit in response to a feedback signal representative of an output of the synchronous flyback converter. The logic circuitry is coupled to the drive circuit and coupled to the comparator. The logic circuitry is also coupled to generate a control signal to control a second switch in response to the drive signal and in response to the compare signal. | 07-24-2014 |
20140204623 | CHARGING CIRCUIT FOR A POWER CONVERTER CONTROLLER - A controller includes a first controller terminal, a second controller terminal, a first p-channel metal-oxide-semiconductor field-effect transistor, and a second pMOS transistor. The first controller terminal is to be coupled to a bypass capacitor coupled to a secondary side of an isolated power converter. The second controller terminal to be coupled to an output node of the secondary side. The first pMOS transistor includes a first source terminal coupled to the second controller terminal, a first drain terminal, and a first body diode. The second pMOS transistor includes a second source terminal coupled to the first controller terminal, a second drain terminal coupled to the first drain terminal, and a second body diode. A cathode of the second body diode is coupled to the second source terminal. An anode of the second body diode is coupled to the second drain terminal. | 07-24-2014 |
20140187019 | DEPOSIT/ETCH FOR TAPERED OXIDE - A process for fabricating a tapered field plate dielectric for high-voltage semiconductor devices is disclosed. The process may include depositing a thin layer of oxide, depositing a polysilicon hard mask, depositing a resist layer and etching a trench area, performing deep silicon trench etch, and stripping the resist layer. The process may further include repeated steps of depositing a layer of oxide and anisotropic etching of the oxide to form a tapered wall within the trench. The process may further include depositing poly and performing further processing to form the semiconductor device. | 07-03-2014 |
20140177285 | ELECTRONIC CIRCUIT CONTROL ELEMENT WITH TAP ELEMENT - An example control element for use in a power supply includes a first terminal, a power MOSFET, and a control circuit. The power MOSFET has a drain terminal, a source terminal, a control terminal, and a tap terminal. In operation, a voltage at the tap terminal is less than and tracks a voltage at the drain terminal when the voltage at the drain terminal is less than a pinch off voltage of the power MOSFET. The control circuit includes a PWM circuit and a start-up circuit. The PWM circuit provides a control signal to the power MOSFET to switch the power MOSFET on and off in response to the feedback signal. The start-up circuit charges a bypass capacitor at the first terminal in response to the voltage at the tap terminal until a voltage at the first terminal reaches a first voltage level. | 06-26-2014 |
20140153297 | POWER SUPPLY CONTROLLER WITH INPUT VOLTAGE COMPENSATION FOR EFFICIENCY AND MAXIMUM POWER OUTPUT - An apparatus includes an ON/OFF controller for regulating an output of a switched mode power supply by selectively enabling current conduction by a power switch within enabled switching cycles and disabling current conduction by the power switch within disabled switching cycles. The controller includes a logic block and a time-to-frequency converter. The logic block generates a drive signal that enables the current conduction by the power switch within respective enabled switching cycles and disables the current conduction by the power switch within respective disabled switching cycles. The time-to-frequency converter generates a variable-frequency clock signal that defines durations of the switching cycles, where the time-to-frequency converter increases a duration of a switching cycle in response to a decrease in duration of current conduction by the power switch in a previously enabled switching cycle. | 06-05-2014 |
20140140115 | Monolithic AC/DC Converter for Generating DC Supply Voltage - An integrated circuit (IC) comprises a rectifier/regulator circuit coupled to receive an ac source voltage and output a regulated dc voltage. The rectifier/regulator circuit includes first and second switching elements that provide charging current when enabled. The first and second switching elements do not provide charging current when disabled. A sensor circuit is coupled to sense the regulated dc voltage and generate a feedback control signal coupled to the rectifier/regulator circuit that enables the first and second switching elements when the regulated do voltage is above a target voltage, and disables the first and second switching elements when the regulated do voltage is below the target voltage. | 05-22-2014 |
20140134966 | NOISE CANCELLATION FOR A MAGNETICALLY COUPLED COMMUNICATION LINK UTILIZING A LEAD FRAME - An integrated circuit package includes an encapsulation and lead frame with a portion of the lead frame disposed within the encapsulation. The lead frame includes a first conductor formed in the lead frame having a first conductive loop and a third conductive loop disposed substantially within the encapsulation. A second conductor is formed in the lead frame galvanically isolated from the first conductor. The second conductor includes a second conductive loop disposed substantially within the encapsulation proximate to the first conductive loop to provide a communication link between the first and second conductors. The third conductive loop is wound in an opposite direction relative to the first conductive loop in the encapsulation. | 05-15-2014 |
20140133186 | SWITCH MODE POWER CONVERTERS USING MAGNETICALLY COUPLED GALVANICALLY ISOLATED LEAD FRAME COMMUNICATION - An integrated circuit package for use in a switch mode power converter comprises an encapsulation and a lead frame. A portion of the lead frame is disposed within the encapsulation. The lead frame includes a first conductor having a first conductive loop disposed substantially within the encapsulation. The lead frame also includes a second conductor galvanically isolated from the first conductor. The second conductor includes a second conductive loop disposed substantially within the encapsulation proximate to and magnetically coupled to the first conductive loop to provide a communication link between the first and second conductors. A first control die including a first control circuit is coupled to the first conductor. A second control die including a second control circuit is coupled to the second conductor. One or more control signals are communicated between the first and second control dice through the communication link. | 05-15-2014 |
20140132184 | Power Supply Circuit with a Control Terminal for Different Functional Modes of Operation - A method of operation for flyback power converter includes operating a controller of the flyback power converter in a regulation mode when a control signal is below a first threshold. The control signal is provided as an input to a terminal of the flyback power converter. When the control signal is below a second threshold and above the first threshold, the controller is operated in a limiting mode. The controller is operated in an external command mode when the control signal is below a third threshold and above the second threshold. Lastly, when the control signal is above the third threshold, the controller is operated in a protection mode. | 05-15-2014 |
20140132182 | FEEDBACK CIRCUIT FOR NON-ISOLATED POWER CONVERTER - A feedback circuit for a power converter (e.g., a non-isolated converter) is disclosed. The feedback circuit may include a sense circuit coupled to receive an output current of the converter. A sense voltage may be generated across the sense circuit and a voltage-to-current converter may be used to convert the sensed voltage into a feedback signal representative of the output current. The voltage-to-current converter may include a variable shunt regulator, resistor, and transistor. A voltage across the shunt regulator may change in response to a change in voltage across the sense circuit, and the feedback signal may change in response to a change in the voltage across the shunt regulator. A controller may be coupled to receive the feedback signal from the feedback circuit and may control switching of a power switch to regulate the output current based at least in part on the feedback signal. | 05-15-2014 |
20140131843 | MAGNETICALLY COUPLED GALVANICALLY ISOLATED COMMUNICATION USING LEAD FRAME - An integrated circuit package includes an encapsulation and a lead frame. A portion of the lead frame is disposed within encapsulation. The lead frame includes a first conductor having a first conductive loop disposed substantially within the encapsulation. The lead frame also includes a second conductor that is galvanically isolated from the first conductor. The second conductor includes a second conductive loop that is substantially disposed within the encapsulation proximate to and magnetically coupled to the first conductive loop to provide a communication link between the first and second conductors. | 05-15-2014 |
20140126249 | SWITCHED AVERAGING ERROR AMPLIFIER - A signal averaging circuit includes a plurality of switched weighted current sources to generate a total amount of charge. The total amount of charge is representative of a weighted sum of a plurality of input signal samples during an active period of a read enable signal. A timing control signal generator is coupled to receive an input signal and the read enable signal and sequentially switch the plurality of switched weighted current sources to adjust the total amount of charge in response to the input signal during the active period of the read enable signal. A storage circuit is coupled to the plurality of switched weighted current sources to convert the total amount of charge into a voltage representative of an output signal. | 05-08-2014 |
20140126246 | METHOD AND APPARATUS FOR DIGITAL CONTROL OF A SWITCHING REGULATOR - An on/off controller device includes a control circuit to generate a control signal to switch a power switch between an on state and an off state to transfer energy from a primary side to a secondary side of a switched mode power supply. A comparator is coupled to generate an enable signal that enables and disables the switching of the power switch by the control circuit. The comparator compares a feedback signal with a variable threshold and switches the enable signal between enabling and disabling the switching of the power switch. The variable threshold is modulated to increase a fundamental frequency of the switching of the power switch by the control circuit. The variable threshold is modulated with a fixed amplitude pulse that is combined with a second threshold to modulate the variable threshold between a first higher value and a second lower value. | 05-08-2014 |
20140124789 | GaN High Voltage HFET with Passivation Plus Gate Dielectric Multilayer Structure - A method of fabricating a multi-layer structure for a power transistor device includes performing, within a reaction chamber, a nitrogen plasma strike, resulting in the formation of a nitride layer directly on a nitride-based active semiconductor layer. A top surface of the nitride layer is then exposed to a second source. A subsequent nitrogen-oxygen plasma strike results in the formation of an oxy-nitride layer directly on the nitride layer. The nitride layer comprises a passivation layer and the oxy-nitride layer comprises a gate dielectric of the power transistor device. | 05-08-2014 |
20140119059 | SPLIT CURRENT MIRROR LINE SENSING - Apparatus and methods for filtering the transients of an input signal of an integrated circuit while maintaining a constant voltage at an input terminal of the integrated circuit are disclosed. In one example, the integrated circuit can be a controller of a switched-mode power supply. The controller can include a line sensing circuit coupled to receive an input signal representative of the line voltage and operable produce an output signal that can be used by other circuits within the controller. The input signal may include a current through a sense resistor coupled between the input of the power supply and the line sensing circuit. The output signal may include a scaled and filtered version of this current. The line sensing circuit can be coupled to the input terminal of the controller to receive the input signal or can directly receive the input signal. | 05-01-2014 |
20140111113 | SIMPLIFIED CURRENT SENSE FOR BUCK LED DRIVER - A current sense and feedback circuit is provided for a non-isolated Buck power converter to maintain constant current load regulation. The Buck converter may have a high side power switch and may include an input port, a switcher unit including a switch and a controller, an inductor coupled to the output, and a freewheeling diode for circulating the inductor current when the switch is open. The simplified current sense and feedback circuit of the power converter may include a current sense resistor module coupled to the freewheeling diode to provide a sense signal to the controller. The controller may also be coupled to the output of the power converter to sense an over voltage condition. The simplified current sense and feedback circuit may provide output regulation while maintaining a low component count, small size, and low loss that makes the power converter suitable for use in compact design applications. | 04-24-2014 |
20140110721 | Second Schottky Contact Metal Layer to Improve GaN Schottky Diode Performance - A Schottky contact is disposed atop the surface of the semiconductor. A first Schottky contact metal layer is disposed atop a first portion of the semiconductor surface. A second Schottky contact metal is disposed atop a second portion of the surface layer and joins the first Schottky contact metal layer. A first. Schottky contact metal layer has a lower work function than the second Schottky contact metal layer. | 04-24-2014 |
20140104895 | METHOD AND APPARATUS FOR PROGRAMMING A POWER CONVERTER CONTROLLER WITH AN EXTERNAL PROGRAMMING TERMINAL HAVING MULTIPLE FUNCTIONS - A power converter includes an energy transfer element and a power switch coupled the energy transfer element and an input of the power converter. A control circuit is coupled to generate a switching signal to control switching of the power switch in response to a feedback signal representative of an output of the power converter. A programming interface circuit is coupled to the control circuit and a coupling switcher coupled to the programming interface circuit. A programming terminal is selectively coupled to the programming interface circuit through the coupling switcher. A programming circuit coupled to the programming terminal is coupled to the programming interface circuit through the coupling switcher during a startup programming condition and during a fault condition of the power converter, and is decoupled from the programming interface circuit by the coupling switcher during a normal operating condition of the power converter. | 04-17-2014 |
20140104888 | SEMICONDUCTOR DEVICE WITH SHARED REGION - A semiconductor device having a JFET and diode, includes a substrate, a second well region, and a second doped region that are of a first conductivity type. The JFET also includes a first well region, a first doped region, and a shared region that are of the second conductivity type. The second well region is disposed in the substrate adjacent to the first well region. A source of the JFET includes the first doped region disposed in the first well region. An anode of the diode includes the second doped region disposed in the second well region. Both a drain of the JFET and a cathode of the diode include the shared region disposed in the first well region. A diode current flows along a first lateral axis of the device while a JFET current flows along a second lateral axis of the device. | 04-17-2014 |
20140104887 | PROGRAMMING OF AN INTEGRATED CIRCUIT ON A MULTI-FUNCTION TERMINAL - Methods and apparatuses for programming a parameter value in an IC (e.g., any power electronic device, such as a controller of a power converter) are disclosed. The parameter can be selected/programmed by selecting a clamp using an external optional (selectively inserted) diode coupled to a multi-function programming terminal. In particular, a controller IC for a power converter can be externally programmed via one or more multiple function terminals during startup of the converter to select between two or more options using the external programming terminal(s). Once programming is complete, internal programming circuitry may be decoupled from the programming terminal and during normal operation the programming terminal may then be used for another function, such as a bypass (BP) terminal to provide a supply voltage to the IC or other required functionalities. | 04-17-2014 |
20140103829 | FEED FORWARD IMBALANCE CORRECTOR CIRCUIT - A circuit includes an input to be coupled to receive a rectified line voltage having a controlled conduction phase angle in each half line cycle. An active device is coupled to a feedback terminal of a controller. The feedback terminal is coupled to receive a feedback signal representative of an output of a power supply. The active device includes a control terminal coupled to receive a signal representative of the input. The active device is coupled to adjust the feedback signal on the feedback terminal in response to the control of the conduction phase angle of the rectified line voltage in each half line cycle. | 04-17-2014 |
20140098571 | SATURATION PREVENTION IN AN ENERGY TRANSFER ELEMENT OF A POWER CONVERTER - A controller for use in a power converter includes logic circuits to turn on and off a switch to regulate an output quantity. A first integrating capacitor is charged with a combination of a first current and a second current while the switch is turned on. The first current is proportional to a reset voltage and the second current is proportional to an input voltage. A reference generation circuit including a second integrating capacitor is charged with the first current during a previous switching cycle of the switch. The reference generation circuit generates a reference voltage in response to the second integrating capacitor. A comparator provides a stop signal to the logic circuits to turn off the switch in response to a comparison of a voltage across the first integrating capacitor with the reference voltage. | 04-10-2014 |
20140097803 | METHOD AND APPARATUS FOR IMPLEMENTING A POWER CONVERTER INPUT TERMINAL VOLTAGE DISCHARGE CIRCUIT - A circuit includes a control circuit coupled to detect whether an electrical energy source is coupled to an input of a power converter. A switch is coupled to the control circuit to transfer energy from the input of the power converter to an output of the power converter during a first operating mode. The control circuit is coupled to drive the switch in the first operating mode when the electrical energy source is coupled to the input of the power converter. The control circuit is coupled to drive the switch in a second operating mode when the electrical energy source is uncoupled from the input of the power converter. The control circuit is coupled to discharge a capacitance coupled between input terminals of the power converter through the switch to a threshold voltage in less than a maximum period of time in the second operating mode. | 04-10-2014 |
20140091859 | DETECTOR CIRCUIT WITH LOW THRESHOLD VOLTAGE AND HIGH VOLTAGE INPUT - An integrated circuit includes a high voltage transistor having a first terminal coupled to sense a high voltage terminal and a control terminal coupled to a regulated voltage, which is regulated with respect to a ground terminal and is substantially less than a high voltage that the high voltage terminal is adapted to withstand. A logic gate is also included and is coupled to be powered from the regulated voltage. The logic gate has an input threshold that is less than the regulated voltage. An input terminal of the logic gate is coupled to a second terminal of the high voltage transistor. An output of the logic gate is coupled to indicate that a voltage sensed between the high voltage terminal and the ground terminal is less than the input threshold voltage of the logic gate. | 04-03-2014 |
20140077266 | Heterostructure Transistor with Multiple Gate Dielectric Layers - A heterostructure semiconductor device includes a first active layer and a second active layer disposed on the first active layer. A two-dimensional electron gas layer is formed between the first and second active layers. A first gate dielectric layer is disposed on the second active layer. A second gate dielectric layer is disposed on the first gate dielectric layer. A passivation layer is disposed over the second gate dielectric layer. A gate extends through the passivation layer to the second gate dielectric layer. First and second ohmic contacts electrically connect to the second active layer. The first and second ohmic contacts are laterally spaced-apart, with the gate being disposed between the first and second ohmic contacts. | 03-20-2014 |
20140071725 | CONTROLLER WITH PUNCTUATED SWITCHING CONTROL CIRCUIT - A power supply controller includes a switching signal generator, a zero crossing detection (ZCD) circuit, first and second logic gates, and an interval generator. The switching signal generator generates a switching signal and the ZCD circuit generates a ZCD signal that pulses each zero-crossing of an ac input voltage. The first logic gate generates a first output when the ZCD signal pulses while the output of the power supply is below a threshold reference. The second logic gate generates a second output when the ZCD signal pulses while the output of the power supply is above the threshold reference. The interval generator is enabled in response to the first output and disabled in response to the second output. The interval generator allows the switching signal to pass through the interval generator to the switch when enabled and does not allow the switching signal to pass when disabled. | 03-13-2014 |
20140063867 | APPARATUS AND METHOD FOR SENSING OF ISOLATED OUTPUT - A switched-mode power supply includes an energy transfer element coupled between a primary side and a secondary side. A first main terminal of a switch is coupled to the energy transfer element and a second main terminal of the switch is coupled to an input of the primary side. A driver circuit is coupled to drive the switch to be open at a first one of a plurality of levels and closed at a second one of the plurality of levels. The driver circuit is coupled to drive the switch to be substantially independent of a voltage between the first and second main terminals at a third one of the plurality of levels. A current conducted between the first and second main terminals at the third one of the plurality of levels is sufficient to only partially discharge a capacitance that is coupled to the first main terminal. | 03-06-2014 |
20140063866 | METHOD AND APPARATUS FOR A CONTROL CIRCUIT RESPONSIVE TO AN IMPEDANCE COUPLED TO A CONTROL CIRCUIT TERMINAL - A controller includes a current sense circuit and a voltage regulation circuit. The current sense circuit generates a first signal that indicates whether a current through a sense terminal exceeds a first threshold current level, which indicates a fault condition of a power converter. The voltage regulation circuit regulates the sense terminal to a first voltage level when the current through the terminal is less than the first threshold current level and regulates the sense terminal to a second voltage level when the current exceeds the first threshold current level. The current sense circuit generates a second signal that indicates whether the current through the sense terminal exceeds a second threshold current level while the sense terminal is regulated to the second voltage level. The response circuit generates an output signal that determines a response of the controller to the fault condition based on the second signal. | 03-06-2014 |
20140063863 | ENERGY TRANSFER ASSEMBLY WITH TUNED LEAKAGE INDUCTANCE AND COMMON MODE NOISE COMPENSATION - An energy transfer assembly includes first and second windings wound around a bobbin. The first winding has a first number of layers proximate to a first end and a second number of layers proximate to a second end of the bobbin. The second winding has a third number of layers proximate to the first end and a fourth number of layers proximate to the second end. At least a portion of one of the first and second windings overlaps at least a portion of the other one of the first and second windings. A degree of overlap between the first and second windings is non-uniform. An isolation barrier is between the first and second windings and around the bobbin. A distance between the isolation barrier and an axis of the bobbin varies along the length of the bobbin. | 03-06-2014 |
20140063862 | VARYING SWITCHING FREQUENCY AND PERIOD OF A POWER SUPPLY CONTROLLER - A controller includes a PWM circuit and a timing circuit. The PWM circuit controls a switch in response to a clock signal. A switching period of the clock signal is based on a charging and discharging time of a capacitor included in the timing circuit. Both first and second current sinks discharge the capacitor while the timing circuit is in a normal discharging mode that is when an on time of the switch is less than a threshold time. The second current sink is prevented from discharging the capacitor such that the capacitor is discharged with the first current sink and not the second current sink while the timing circuit is in an alternative discharging mode that is when the on time of the switch exceeds the threshold time. The discharging of the capacitor in the alternative discharging mode increases the switching period of the clock signal. | 03-06-2014 |
20140055293 | DIGITAL-TO-ANALOG CONVERTER TO PRODUCE PAIRED CONTROL SIGNALS IN A POWER SUPPLY CONTROLLER - An controller for use in a power supply includes a variable oscillator and a digital-to-analog converter (DAC). The variable oscillator generates a switching signal to control a first switch of the power supply to regulate an output current of the power supply. The variable oscillator sets a duration of an on-time of the switching signal to be inversely proportional to a magnitude of a first analog signal. The variable oscillator also sets a switching period of the switching signal to be inversely proportional to a magnitude of a second analog signal. The digital-to-analog converter (DAC) converts binary digits into the first and second analog signals, such that a sum of the magnitude of the first analog signal and the magnitude of the second analog signal is a fixed value. | 02-27-2014 |
20140049241 | DIMMING CONTROL FOR A SWITCHING POWER SUPPLY - An example controller includes a measurement block and a drive block. The measurement block determines an amount of time that a dimmer circuit, that is coupled to an input of a power supply, disconnects an ac input voltage. The drive block generates a drive signal to control switching of a switch included in the power supply. The drive block operates a closed loop dimming control when the amount of time is less than or equal to a threshold and operates an open loop dimming control when the amount of time is greater than the threshold. The closed loop dimming control includes setting one or more operating conditions of the drive signal in response to a feedback signal that is representative of an output quantity of the power supply. The open loop dimming control includes holding the one or more operating conditions of the drive signal to a value. | 02-20-2014 |
20140045318 | FORMING A TAPERED OXIDE FROM A THICK OXIDE LAYER - Processes for forming a tapered field plate dielectric in a semiconductor substrate are provided. The process may be used to form a variety of types of devices, such as Schottky diodes, HVFETs, JFET, IGBT, bipolar transistors, and the like. The process may include etching a trench in a semiconductor wafer, depositing an insulating layer on the semiconductor wafer to form a gap within the trench, depositing a masking layer on the insulating layer, and alternatingly etching the masking layer and the insulating layer to form a tapered field plate dielectric region. | 02-13-2014 |
20140042533 | Segmented Pillar Layout for a High-Voltage Vertical Transistor - In one embodiment, a transistor fabricated on a semiconductor die includes a first section of transistor segments disposed in a first area of the semiconductor die, and a second section of transistor segments disposed in a second area of the semiconductor die adjacent the first area. Each of the transistor segments in the first and second sections includes a pillar of a semiconductor material that extends in a vertical direction. First and second dielectric regions are disposed on opposite sides of the pillar. First and second field plates are respectively disposed in the first and second dielectric regions. Outer field plates of transistor segments adjoining first and second sections are either separated or partially merged. | 02-13-2014 |
20140036551 | METHOD AND APPARATUS FOR ON/OFF CONTROL OF A POWER CONVERTER - A power converter includes an energy transfer element coupled between a power converter input and a power converter output. A power switch is coupled to the energy transfer element and the power converter input. A feedback sampling circuit is coupled to receive a feedback signal representative of the power converter output to generate at least one feedback signal sample during each switching cycle. A switch conduction scheduling circuit is coupled to set a number of enabled cycles and a number of disabled cycles of the power switch in a plurality of future switching cycles in response to the feedback signal samples for each present switching cycle and one or more past switching cycles. A switch conduction control circuit is coupled to enable or disable conduction of the power switch during a switching cycle to control an amount of energy transferred from the power converter input to the power converter output. | 02-06-2014 |
20140033527 | LOW-COST TRANSFORMER ASSEMBLY - Power is supplied on a circuit board assembly by attaching a drum core inductor to a circuit board. The drum core inductor has a first winding wound around the drum core inductor. The first winding has first and second ends coupled to the drum core inductor. A bobbin is attached to the circuit board. The bobbin has a second winding wound around the bobbin. The second winding has first and second ends coupled to the bobbin. The drum core inductor and the bobbin are attached to the circuit board. The drum core inductor is inside an opening of the bobbin. The drum core inductor and the bobbin are detached from each other. A power switch coupled to the first winding is switched to control a transfer of energy from an input power source through the first and second windings to a load coupled to the second winding. | 02-06-2014 |
20140030868 | DEPOSIT/ETCH FOR TAPERED OXIDE - A process for fabricating a tapered field plate dielectric for high-voltage semiconductor devices is disclosed. The process may include depositing a thin layer of oxide, depositing a polysilicon hard mask, depositing a resist layer and etching a trench area, performing deep silicon trench etch, and stripping the resist layer. The process may further include repeated steps of depositing a layer of oxide and anisotropic etching of the oxide to form a tapered wall within the trench. The process may further include depositing poly and performing further processing to form the semiconductor device. | 01-30-2014 |
20140022825 | METHOD AND APPARATUS TO SELECT A PARAMETER/MODE BASED ON A MEASUREMENT DURING AN INITIALIZATION PERIOD - A power supply control circuit includes a threshold detection circuit coupled to a first terminal to measure a signal at the first terminal during a duration of an initialization period after a fourth terminal has been charged to a supply threshold value. A regulator circuit is coupled between a second terminal and the fourth terminal to charge the fourth terminal to the supply threshold value during the initialization period of the power supply control circuit. A selection circuit is coupled to the threshold detection circuit to select a parameter/mode in response to the signal measured at the first terminal. The first terminal is further coupled to receive one or more additional signals during normal operation at times other than the initialization period to provide at least one additional function for the power supply control circuit after the initialization period is complete. | 01-23-2014 |
20140016377 | METHOD AND APPARATUS TO CONTROL A POWER CONVERTER HAVING A LOW LOOP BANDWIDTH - A controller for use in a power converter includes a comparator coupled to receive a signal representative of an output of the power converter. A counter is coupled to an output of the comparator to sample the output of the comparator a plurality of times within a period. A state machine is coupled to an output of the counter to control switching of the power converter according to one of a plurality of operating condition states in response to the output of the counter. The state machine is coupled to be updated at an end of the period. | 01-16-2014 |
20140009086 | SINGLE-STAGE POWER SUPPLY WITH POWER FACTOR CORRECTION AND CONSTANT CURRENT OUTPUT - An example power supply includes an energy transfer element, a switch, and a controller. The switch is coupled to the energy transfer element to control a transfer of energy from an input to a galvanically isolated output of the power supply. The controller includes a delayed ramp generator, an integrator, an arithmetic operator, and a drive signal generator. The integrator generates a first signal responsive to integrating an input current of the power supply. The arithmetic operator generates a second signal responsive to the first signal and responsive to a ratio of a rectified input voltage to a dc output voltage of the power supply. The drive signal generator generates a drive signal in response to a delayed ramp signal and the second signal to control switching of the switch to provide power factor correction of the power supply and to provide a regulated current at the output. | 01-09-2014 |
20140001515 | STATIC DISCHARGE SYSTEM | 01-02-2014 |
20140001479 | SWITCHING DEVICE WITH CHARGE DISTRIBUTION STRUCTURE | 01-02-2014 |
20130342129 | FLICKER PREVENTION WITH SWITCHED BULK CAPACITOR - This relates to an apparatus and method for selectively adding a capacitance to an input of a power converter of a power conversion system. A power conversion system may selectively introduce additional input capacitance in response to an input voltage. In one example, a power conversion system operates in a first mode (dimming mode) and engages a selective capacitor circuit to introduce additional capacitance to an input of a power converter. In a second mode (non-dimming mode), the power conversion system disengages the selective capacitor circuit from the input of the power converter. | 12-26-2013 |
20130336022 | SAMPLE AND HOLD BUFFER - This relates to sampling a feedback signal representative of an output of a power converter. The sampling is performed using a buffer sampling circuit having three sample and hold stages coupled in series to sense and store the feedback signal. The first stage is coupled to sample and hold the feedback signal on a capacitor. If the output diode is conducting, the sampled signal is transferred to the second stage. If the output diode is conducting, the first stage will sample the feedback signal and the sampled signal will be transferred to be sampled and held by the second stage. When the output diode stops conducting, the sampled voltage held by the second stage is transferred to the third stage. The third stage stores the sampled voltage on a capacitor. As such, the controller may sample the feedback signal near the end of the output diode conduction time. | 12-19-2013 |
20130336021 | VARIABLE FREQUENCY TIMING CIRCUIT FOR A POWER SUPPLY CONTROL CIRCUIT - A timing circuit of a controller generates a clock signal having a switching period for use by a pulse width modulation (PWM) circuit to control a switch of a power supply. The switching period of the clock signal is based on a charging time plus a discharging time of a capacitor included in the timing circuit. A first current source charges the capacitor while the timing circuit is in a normal charging mode. A second current source charges the capacitor while the timing circuit is in an alternative charging mode that is when the on time of the switch exceeds a threshold time. The current provided by the second current source is less than the current provided by the first current source such that the switching period of the clock signal is increased in response to the timing circuit entering the alternative charging mode. | 12-19-2013 |
20130336020 | METHOD AND APPARATUS TO REDUCE AUDIO FREQUENCIES IN A SWITCHING POWER SUPPLY - An example power supply regulator includes an energy transfer element, a switch, and a controller. The controller includes a switch signal generator, a modulation circuit, and a multi-cycle modulator circuit. The modulation circuit modulates the period of a modulation switching signal when an equivalent switching frequency is greater than a reference frequency and fixes the switching period when the equivalent switching frequency is less than the reference frequency. The multi-cycle modulator circuit enables the switch signal generator to provide a switch signal uninterrupted if the equivalent switching frequency is greater than the reference frequency and disables the switch signal generator for a first time period and then enables the switch signal generator for a second time period when the equivalent frequency is less than the reference frequency. The multi-cycle modulator circuit varies the first time period to regulate the output. | 12-19-2013 |
20130336019 | METHOD AND APPARATUS FOR DETERMINING ZERO-CROSSING OF AN AC INPUT VOLTAGE TO A POWER SUPPLY - An example controller for a power supply includes a first circuit and a drive signal generator. The first circuit receives a first signal representative of a switch current flowing through a switch of the power supply and then generates a second signal in response the switch current not reaching a current threshold within an amount of time. The second signal indicates when a dimming circuit at an input of the power supply is utilized. The drive signal generator generates a drive signal to control switching of the switch in response to the second signal, where energy is transferred across an energy transfer element of the power supply in response to the switching of the switch. | 12-19-2013 |
20130330888 | IN SITU GROWN GATE DIELECTRIC AND FIELD PLATE DIELECTRIC - Methods and apparatuses are disclosed for providing heterostructure field effect transistors (HFETs) with high-quality gate dielectric and field plate dielectric. The gate dielectric and field plate dielectric are in situ deposited on a semiconductor surface. The location of the gate electrode may be defined by etching a first pattern in the field plate dielectric and using the gate dielectric as an etch-stop. Alternatively, an additional etch-stop layer may be in situ deposited between the gate dielectric and the field plate dielectric. After etching the first pattern, a conductive material may be deposited and patterned to define the gate electrode. Source and drain electrodes that electrically contact the semiconductor surface are formed on opposite sides of the gate electrode. | 12-12-2013 |
20130329462 | POWER LIMITING BY MODULATING CLOCK - A clock generation circuit for use in a power converter controller includes a modulation signal generator that is coupled to generate a modulation signal in response to an input sense signal representative of an input voltage of a power converter. The modulation signal is responsive to the input sense signal when the input sense signal is greater than a first input threshold. A clock modulator circuit is coupled to receive the modulation signal and a first clock signal from an oscillator. The clock modulator circuit is coupled to generate a second clock signal in response to the first clock signal and the modulation signal. An average frequency of the second clock signal is responsive to the modulation signal. | 12-12-2013 |
20130328114 | Integrated Transistor and Anti-Fuse as Programming Element for a High-Voltage Integrated Circuit - A semiconductor device includes an N type well region in a P type substrate. A source region of a MOSFET is laterally separated from a boundary of the well region, which includes the drain of the MOSFET. An insulated gate of the MOSFET extends laterally from the source region to at least just past the boundary of the well region. A polysilicon layer, which forms a first plate of a capacitive anti-fuse, is insulated from an area of the well region, which forms the second plate of the anti-fuse. The anti-fuse is programmed by application of a voltage across the first and second capacitive plates sufficient to destroy at least a portion of the second dielectric layer, thereby electrically shorting the polysilicon layer to the drain of the HVFET. | 12-12-2013 |
20130328060 | LAYOUT DESIGN FOR A HIGH POWER, GaN-BASED FET - A FET includes a first and second set of finger arrays that each include a source, gate and drain. A first source pad is electrically coupled to source electrodes in the first set of finger arrays. A second source pad is electrically coupled to the source electrodes in the second set of finger arrays. A common drain pad is electrically coupled to drain electrodes in the first and second set of finger arrays. A first gate pad is electrically coupled to gate electrodes in the first set of finger arrays. A second gate pad is electrically coupled to gate electrodes in the second set of finger arrays. A substrate is also provided on which are disposed the first and second set of finger arrays, the first and second source pads, the common drain pad, and the first and second gate pads. | 12-12-2013 |
20130320882 | INTEGRATED ON-TIME EXTENSION FOR NON-DISSIPATIVE BLEEDING IN A POWER SUPPLY - An example controller for a switched mode power supply includes a zero crossing detector, drive logic, and a logic gate. The zero-crossing detector generates a zero-crossing signal indicating a zero-crossing condition in the power supply. The drive logic generates a drive logic output signal in response to the zero-crossing signal and in response to a feedback signal, where the drive logic output signal is representative of an on-time of a switch to regulate an output of the power supply. The logic gate is coupled to receive a first signal representative of a current through the switch and a second signal representative of a zero-crossing time threshold. The logic gate is further coupled to extend the on-time of the switch until current through the switch reaches a zero-crossing current threshold or until the on-time of the switch reaches the zero-crossing time threshold. | 12-05-2013 |
20130320482 | High-Voltage Monolithic Schottky Device Structure - A semiconductor device includes a pillar formed on a substrate of the same conductivity type. The pillar has a vertical thickness that extends from a top surface down to the substrate. The pillar extends in first and second lateral directions in a loop shape. First and second dielectric regions are disposed on opposite lateral sides of the pillar, respectively. First and second conductive field plates are respectively disposed in the first and second dielectric regions. A metal layer is disposed on the top surface of the pillar, the metal layer forming a Schottky diode with respect to the pillar. When the substrate is raised to a high-voltage potential with respect to both the metal layer and the first and second field plates, the first and second field plates functioning capacitively to deplete the pillar of charge, thereby supporting the high-voltage potential along the vertical thickness of the pillar. | 12-05-2013 |
20130320199 | OPTICALLY CONTROLLED SILICON CARBIDE AND RELATED WIDE-BANDGAP TRANSISTORS AND THYRISTORS - An optically active material is used to create power devices and circuits having significant performance advantages over conventional methods for affecting optical control of power electronics devices and circuits. A silicon-carbide optically active material is formed by compensating shallow donors with the boron related D-center. The resulting material can be n-type or p-type but it is distinguished from other materials by the ability to induce persistent photoconductivity in it when illuminated by electromagnetic radiation with a photon energy in excess of the threshold energy required to photoexcite electrons from the D-center to allowed states close to the conduction band edge, which varies from polytype to polytype. | 12-05-2013 |
20130307495 | METHOD AND APPARATUS TO INCREASE EFFICIENCY IN A POWER FACTOR CORRECTION CIRCUIT - A power factor correction (PFC) controller includes a capacitor, an error amplifier, a switching frequency adjuster, a comparator, and a drive signal generator. The current source generates a current that is representative of an instantaneous input voltage of a PFC converter to charge the capacitor when a power switch of the PFC converter is off. The switching frequency adjuster generates an adjusted error signal in response to an error signal generated by the error amplifier. The comparator compares a voltage on the capacitor with the adjusted error signal to generate a first signal to end an off time of the power switch. The drive signal generator controls switching of the power switch in response to the first signal. The switching frequency adjuster changes the adjusted error signal in response to changes in the error signal to adjust an average switching frequency of the power switch. | 11-21-2013 |
20130278159 | BLEEDER CIRCUIT FOR USE IN A POWER SUPPLY - A bleeder circuit for use in a power supply of a lighting system includes a first terminal to be coupled to a first input of the power supply. A second terminal is to be coupled to a second input of the power supply. An edge detection circuit is coupled between the first and second terminals of the bleeder circuit. The edge detection circuit is coupled to output an edge detection signal in response to an input signal between the first and second inputs. A variable current circuit is coupled to the edge detection circuit and coupled between the first and second terminals of the bleeder circuit. The variable current circuit is coupled to conduct a bleeder current between the first and second terminals of the bleeder circuit in response to the edge detection signal. | 10-24-2013 |
20130250457 | ADJACENT TERMINAL FAULT DETECTION - This relates to detecting unwanted couplings between a protected terminal and other terminals in an integrated controller of a power supply. Offset and clamp circuitry may apply a positive or negative offset voltage and clamp current to one or more terminals of the controller. In the event that a terminal having the offset voltage and clamp current is accidentally coupled to the protected terminal, the offset voltage and clamp current may be applied to the protected terminal. The protected terminal may be coupled to a fault detection circuitry operable to detect a fault signal at the protected terminal. The fault detection circuitry of the controller may cause the power supply to shut down in response to a detection of the fault signal at the protected terminal or may cause the power supply to shut down in response to a detection of a predefined threshold number of cycles in which the fault signal is detected. | 09-26-2013 |
20130242619 | RESET VOLTAGE CIRCUIT FOR A FORWARD POWER CONVERTER - An example method includes controlling a duty ratio of a switch to regulate an output of a forward power converter and storing a first voltage. The first voltage is equal to an input voltage of the forward power converter when the input voltage is at a steady-state value. The method also includes resetting a transformer of the forward power converter when the switch is in an OFF state by setting a voltage across a primary winding of the transformer to the stored first voltage in response to a drop in the input voltage to below the steady-state value. Further included in the method is increasing the duty cycle of the switch to greater than fifty (50) percent in response to the drop in the input voltage to maintain regulation at the output of the forward power converter. | 09-19-2013 |
20130241440 | PHASE ANGLE MEASUREMENT OF A DIMMING CIRCUIT FOR A SWITCHING POWER SUPPLY - An example switched mode power supply includes a timer, a threshold adjust circuitry, a comparator, and a control circuitry. The timer times a duration between crossings of a phase-dimmed signal across a first threshold. The threshold adjust circuitry adjusts a second threshold representative of a desired output of the switched mode power supply, where the second threshold is adjusted responsive to the timed duration between crossings. The comparator compares a feedback signal with the second threshold and generates a comparison result. The control circuitry controls switching of a power switch responsive to the comparison result to regulate the output of the switched mode power supply. | 09-19-2013 |
20130234243 | Checkerboarded High-Voltage Vertical Transistor Layout - In one embodiment, a transistor fabricated on a semiconductor die is arranged into sections of elongated transistor segments. The sections are arranged in rows and columns substantially across the semiconductor die. Adjacent sections in a row or a column are oriented such that the length of the transistor segments in a first one of the adjacent sections extends in a first direction, and the length of the transistor segments in a second one of the adjacent sections extends in a second direction, the first direction being substantially orthogonal to the second direction. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. | 09-12-2013 |
20130232358 | METHOD AND APPARATUS FOR INCREASING THE POWER CAPABILITY OF A POWER SUPPLY - One controller for a power supply includes an oscillator, a first circuit, a counter, and a pause circuit. The first circuit generates a drive signal to control switching of a switch to regulate an output of the power supply. The first circuit initiates an on time period of the switch in response to both a clock signal of the oscillator and an enable signal that is generated in response to a feedback signal of the power supply. The counter receives the enable signal and generates an output signal when the counter reaches a count value indicating that the enable signal has been idle for an amount of time. The pause circuit generates a pause signal in response to the output signal of the counter. The oscillator is paused in response to the pause signal and a maximum on time period of the switch is extended while the oscillator is paused. | 09-05-2013 |
20130223106 | ASYMMETRIC SWITCH FORWARD CONVERTER - A switching circuit for use in a power converter includes a first active switch coupled between a first terminal of an input of the power converter and a first terminal of a primary winding of a transformer. A second active switch is coupled between a second terminal of the input and a second terminal of the primary winding. An output capacitance of the first active switch is greater than an output capacitance of the second active switch. A first passive switch is coupled between the second terminal of the primary winding and the first terminal of the input. A second passive switch is coupled between the second terminal of the input and the first terminal of the primary winding. A reverse recovery time of the first passive switch is greater than a reverse recovery time of the second passive switch. | 08-29-2013 |
20130223105 | METHOD AND APPARATUS FOR A POWER SUPPLY CONTROLLER RESPONSIVE TO A FEEDFORWARD SIGNAL - An example power converter includes an energy transfer element, a switch, a feedback circuit, a feedforward circuit, and an integrated circuit controller. The integrated circuit controller includes a gain selector circuit and a switch duty cycle controller. The gain selector circuit selects a gain multiplier according to a value of a feedforward signal generated by the feedforward circuit and applies the gain multiplier to the feedforward signal to generate a duty cycle adjust signal. The switch duty cycle controller generates a drive signal to control the switch in response to a feedback signal generated by the feedback circuit. A duty cycle of the drive signal is varied in response to the duty cycle adjust signal such that the duty cycle varies according to a plurality of linear functions over a range of values of the feedforward signal. | 08-29-2013 |
20130215656 | LATCHING COMPARATOR - A latching comparator includes a switching logic circuit coupled to receive a latching signal, a first signal and a second signal. An output circuit having an input terminal is coupled to the switching logic circuit. The input terminal of the output circuit is coupled to receive both the first and second signals through the switching logic circuit in response to the latching signal being in a first state. The input terminal of the output circuit is coupled to receive only one of the first and second signals through the switching logic circuit in response to a signal representative of an output terminal of the output circuit and in response to the latching signal being in a second state. | 08-22-2013 |
20130215650 | VARIABLE TIME CLAMP FOR A POWER SUPPLY CONTROLLER - An example integrated circuit for use in a power supply includes a feedback terminal, a controller and a clamp. The feedback terminal is to be coupled to receive a feedback signal that is representative of a bias voltage across a bias winding of the power supply. The controller is to be coupled to control switching of a power switch included in the power supply in response to the feedback signal. The clamp is coupled to clamp the feedback terminal to a voltage for at least a time that the bias voltage is negative with respect to an input return of the power supply. | 08-22-2013 |
20130214702 | POWER CONVERTER WITH COMPENSATION CIRCUIT FOR ADJUSTING OUTPUT CURRENT PROVIDED TO A CONSTANT LOAD - A method for use in a power converter includes generating a peak input voltage signal that is representative of a peak value of the input voltage for phase angles less than a phase angle threshold and is representative of a value that is less than the peak value of the input voltage for phase angles greater than the phase angle threshold. The method also includes controlling a switching of a switch to regulate an output current of the power converter in response to the peak input voltage signal and the feedback signal. A compensation current is then added to the peak input voltage signal when the phase angle is greater than the phase angle threshold to allow for natural dimming at an output of the power converter. | 08-22-2013 |
20130207192 | Power Integrated Circuit with Incorporated Sense FET - In one embodiment, a power integrated circuit device includes a main lateral high-voltage field-effect transistor (HVFET) and an adjacently-located lateral sense FET, both of which are formed on a high-resistivity substrate. A sense resistor is formed in a well region disposed in an area of the substrate between the HVFET and the sense FET. A parasitic substrate resistor is formed in parallel electrical connection with the sense resistor between the source regions of the HVFET and the sense FET. Both transistor devices share common drain and gate electrodes. When the main lateral HVFET and the sense FET are in an on-state, a voltage potential is produced at the second source metal layer that is proportional to a first current flowing through the lateral HVFET. | 08-15-2013 |
20130194835 | FLYBACK CONVERTER WITH FORWARD CONVERTER RESET CLAMP - A power supply includes a forward converter having a first transformer coupled to an input of the power supply and to a first voltage output. The power supply also includes a separate flyback converter having a second transformer that is coupled to the input and to a second voltage output. A clamp reset circuit is coupled to the first transformer and to the second transformer. The clamp reset circuit includes a capacitor and a voltage limiting element. The voltage limiting element is coupled to prevent energy received at the capacitor from both the power converters from exceeding a threshold. The voltage limiting element limits a voltage on the capacitor. | 08-01-2013 |
20130194834 | POWER SYSTEM WITH SHARED CLAMP RESET - An example power supply includes a first power converter, a second power converter, and a shared clamp reset circuit. The first power converter is adapted to convert an input to a first voltage output and includes a first diode and a first transformer having a first primary winding. The second power converter is adapted to convert the input to a second voltage output and includes a second diode and a second transformer having a second primary winding. The shared clamp reset circuit is included in the first power converter and is coupled to the cathode of the first diode. The shared clamp reset circuit also includes a clamp connection that is coupled to the cathode of the second diode. The shared clamp reset circuit is adapted to manage leakage inductance energy within the first transformer and within the second transformer. | 08-01-2013 |
20130193864 | LED DIMMING CIRCUIT FOR SWITCHED DIMMING - A light emitting diode (LED) dimming module includes an energy storage circuit, a load interface circuit, and a switch circuit. The energy storage circuit provides a substantially continuous current in response to a converter current. The load interface circuit provides a modulated load current in response to the continuous current. The switch circuit, which is operatively coupled to the load interface circuit, switches in accordance with a duty cycle. The modulated load current is based on the duty cycle. | 08-01-2013 |
20130187219 | High-Voltage Vertical Transistor With a Varied Width Silicon Pillar - In one embodiment, a vertical HVFET includes a pillar of semiconductor material a pillar of semiconductor material arranged in a loop layout having at least two substantially parallel and substantially linear fillet sections each having a first width, and at least two rounded sections, the rounded sections having a second width narrower than the first width, a source region of a first conductivity type being disposed at or near a top surface of the pillar, and a body region of a second conductivity type being disposed in the pillar beneath the source region. First and second dielectric regions are respectively disposed on opposite sides of the pillar, the first dielectric region being laterally surrounded by the pillar, and the second dielectric region laterally surrounding the pillar. First and second field plates are respectively disposed in the first and second dielectric regions. | 07-25-2013 |
20130181624 | FEED FORWARD IMBALANCE CORRECTOR CIRCUIT - A circuit includes a first active device is coupled between a third terminal and a second terminal. The first active device has a control terminal coupled a first terminal to receive a signal representative of a rectified input voltage. A second active device is coupled between the control terminal of the first active device and the second terminal. The second active device has a control terminal coupled to a fourth terminal. The second active device is coupled to be controlled in response to a bypass voltage at the fourth terminal. The first active device is coupled to be controlled in response to the rectified input voltage and the bypass voltage. | 07-18-2013 |
20130170251 | METHOD AND APPARATUS FOR SENSING MULTIPLE VOLTAGE VALUES FROM A SINGLE TERMINAL OF A POWER CONVERTER CONTROLLER - A controller for use in a power converter includes a sensor coupled to receive a signal from a single terminal of the controller. The signal from the single terminal represents an output voltage of the power converter during at least a portion of an off time of a power switch and a line input voltage during a portion of an on time of the power switch. A switching control is to be coupled to switch the power switch to regulate the output of the power converter in response to the sensor. A power limiter is coupled to the sensor to output a power limit signal to the switching control in response to the line input voltage of the power converter. The switching control is further coupled to switch the power switch to regulate the output of the power converter in response to the power limit signal. | 07-04-2013 |
20130157440 | Composite wafer for fabrication of semiconductor devices - A composite wafer includes a first substrate having a first vertical thickness and a top surface, the top surface being prepared in a state for subsequent semiconductor material epitaxial deposition. A carrier substrate is disposed beneath the first substrate. The carrier substrate has a second vertical thickness greater than the first vertical thickness. An interlayer bonds the first substrate to the carrier substrate. | 06-20-2013 |
20130155733 | GENERATING A FAST RESET-SIGNAL USING A FAULT-PROTECTION LATCH - Methods and apparatuses are disclosed for monitoring an ac input for fault conditions. The ac input may be monitored by a latch-reset that uses the ac input to charge a line detection capacitor. The latch-reset may be configured such that the voltage at one end of the line detection capacitor drops below a line detection threshold voltage when the ac input is removed for longer than an allowable period of time or if the voltage of the ac input falls below an acceptable value. The drop in voltage at the end of the capacitor may cause an electrically coupled transistor to switch, thereby causing a reset-signal to be generated. | 06-20-2013 |
20130155724 | DETECTING OUTPUT DIODE CONDUCTION TIME FOR CABLE DROP COMPENSATION OF A POWER CONVERTER - An example controller for a power converter to provide power to a load through a distribution network includes a control circuit and a cable drop compensator. The control circuit outputs a drive signal to control switching of a switch to regulate an output of the power converter in response to a feedback signal. The cable drop compensator is coupled to adjust the feedback signal in response to a conduction time of an output diode of the power converter to compensate for a distribution voltage dropped across the distribution network. | 06-20-2013 |
20130146891 | ENHANCEMENT-MODE HFET CIRCUIT ARRANGEMENT HAVING HIGH POWER AND A HIGH THRESHOLD VOLTAGE - A circuit includes input drain, source and gate nodes. The circuit also includes a group III nitride enhancement-mode HFET having a source, drain and gate and a voltage shifter having a first terminal connected to the gate of the enhancement mode HFET at a common junction. The circuit also includes a load resistive element connected to the common junction. The drain of the enhancement-mode HFET serves as the input drain node, the source of the enhancement-mode HFET serves as the input source node and a second terminal of the voltage shifter serves as the input gate node. | 06-13-2013 |
20130141955 | CONTROLLER WITH PUNCTUATED SWITCHING CONTROL CIRCUIT - An example controller for use in a power supply includes a zero crossing detection (ZCD) circuit, a threshold detection circuit, and a punctuated switching control circuit. The ZCD circuit generates a ZCD signal that pulses each zero-crossing of an ac input voltage. The threshold detection circuit receives and compares an output of the power supply with a threshold reference. The punctuated switching control circuit generates a switching signal to control a switch to regulate the output of the power supply. The switching signal is generated to have intervals of switching and intervals of no switching, where each interval of switching begins responsive to the output of the power supply dropping below the threshold reference and each interval of no switching begins responsive to the output rising above the threshold reference. Each interval has a beginning that is synchronized with a pulse of the ZCD signal. | 06-06-2013 |
20130141948 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH OUTPUT RESET IN A POWER CONVERTER - A control circuit includes a feedback circuit, a drive signal generator, an unregulated dormant mode and output reset control circuit, and a counter. The feedback circuit generates an enable signal and in response, the drive signal generator regulates the output of the power converter. The unregulated dormant mode and output reset control circuit powers down the drive signal generator such that the regulation is ceased when the energy requirement at the output has fallen below a threshold. The drive signal generator is then powered up after a first period of time such that the regulation resumes. The counter then counts cycles of a clock signal for which the enable signal indicates an increase in the energy requirement at the output. The counter disables the drive signal generator when a count of the counter reaches a threshold number to discharge the output to less than a regulation output voltage value. | 06-06-2013 |
20130140605 | GaN high voltage HFET with passivation plus gate dielectric multilayer structure - A method of fabricating a multi-layer structure for a power transistor device includes performing, within a reaction chamber, a nitrogen plasma strike, resulting in the formation of a nitride layer directly on a nitride-based active semiconductor layer. A top surface of the nitride layer is then exposed to a second source. A subsequent nitrogen-oxygen plasma strike results in the formation of an oxy-nitride layer directly on the nitride layer. The nitride layer comprises a passivation layer and the oxy-nitride layer comprises a gate dielectric of the power transistor device. | 06-06-2013 |
20130140585 | JUNCTION BARRIER SCHOTTKY RECTIFIERS HAVING EPITAXIALLY GROWN P+-N JUNCTIONS AND METHODS OF MAKING - A junction barrier Schottky (JBS) rectifier device and a method of making the device are described. The device comprises an epitaxially grown first n-type drift layer and p-type regions forming p | 06-06-2013 |
20130128625 | APPARATUS AND METHOD FOR SENSING OF ISOLATED OUTPUT - A power converter includes a current controller coupled to an energy transfer element to selectively enable a first, second or third current in the current controller. The first current is substantially zero, the second current is greater than the third current, and the third current is greater than the first current. The third current only partially discharges a capacitance coupled to the energy transfer element and the current controller. A control circuit is to be coupled to the current controller to selectively enable the first, second or third current in the current controller. A first feedback circuit is coupled to generate a first feedback signal while the first current is enabled by the current controller after a full discharge pulse. A second feedback circuit is coupled to generate a second feedback signal while the first current is enabled in the controller after a partial discharge pulse. | 05-23-2013 |
20130121040 | METHOD AND APPARATUS TO REGULATE AN OUTPUT VOLTAGE OF A POWER CONVERTER AT LIGHT/NO LOAD CONDITIONS - An example controller for a primary side control power converter includes a feedback circuit, a driver circuit, and an adjustable voltage reference circuit. The feedback circuit compares a feedback signal representative of a bias winding voltage of the power converter with a voltage reference. The driver circuit outputs a switching signal having a switching period to control a switch to regulate an output of the power converter in response to the feedback signal and enables or disables a switching period based on the output of the feedback circuit. The adjustable voltage reference circuit adjusts the voltage reference by a first amount in response to a first number of disabled switching periods indicating a first load condition at the output of the power converter and by a second amount in response to a second number of disabled switching periods indicating a second load condition at the output of the power converter. | 05-16-2013 |
20130121035 | ULTRA LOW STANDBY CONSUMPTION IN A HIGH POWER POWER CONVERTER - A power converter includes a dc input having first and second terminals. A main converter is coupled to the first terminal of the dc input. A standby circuit coupled to the second terminal of the dc input and the main converter. The main converter is coupled to control a transfer of energy from the dc input through the standby circuit to a main output of the main converter during a normal operating condition of the power supply. The standby circuit is coupled to decouple the main converter from the second terminal of the dc input during a standby operating condition of the power converter. A standby converter is coupled to the first and second terminals of the dc input to control a transfer of energy from the dc input to a standby output of the standby converter during the standby operating condition of the power converter. | 05-16-2013 |
20130106379 | CONTROLLER COMPENSATION FOR FREQUENCY JITTER | 05-02-2013 |
20130100714 | POWER CONTROLLER WITH SMOOTH TRANSITION TO PULSE SKIPPING - A power converter control circuit includes a ramp signal circuit, a blanking circuit, and a pulse driver circuit. The ramp signal circuit provides a ramp signal in response to a power converter feedback signal and an enable signal. The blanking circuit provides a blanking signal in response to the ramp signal and a clock signal. The blanking signal is provided when both the ramp signal is increasing in value and the enable signal indicates a light load operating condition. The pulse driver circuit provides a power switch control pulse in accordance with the clock signal and in the absence of the blanking signal. | 04-25-2013 |
20130100710 | ACTIVE SURGE PROTECTION IN A POWER SUPPLY - A surge protection module is disclosed. An example surge protection module includes a first terminal coupled to a first output terminal of a rectifier of a power supply. A second terminal is coupled to a first input terminal of a switching converter of the power supply. A third terminal is coupled to a second output terminal of the rectifier and a second input terminal of the switching converter. A variable resistance circuit is coupled between the first and second terminals. A control circuit is coupled between the first and third terminals and coupled to control the variable resistance circuit. A resistance of the variable resistance circuit is responsive to a magnitude of a voltage between the first and third terminals. | 04-25-2013 |
20130083579 | PRE-BIASED SAMPLING FILTER - Methods and apparatuses are disclosed for sampling a feedback signal representative of an output of a power converter using a pre-biased filter capacitor. The pre-biased filter capacitor provides accurate sampling of the feedback signal during various load conditions. The pre-biased filter may be pre-charged to a pre-bias voltage that is below the regulated voltage of the feedback signal to reduce the amount of time required to charge the pre-biased filter capacitor to the regulated voltage of the feedback signal. | 04-04-2013 |
20130083572 | PROTECTION FOR INADVERTENT MISSING FEEDBACK VOLTAGE SIGNAL - Methods and apparatuses are disclosed for providing improved feedback sampling in a primary-side regulated power converter. A test sample may be taken prior to the default feedback sample. The voltage of the test sample may be compared to the voltage of the default feedback sample to determine if the voltage difference between the two samples exceeds a threshold. If the default sample is lower than the test sample by more than the threshold, the default sample may be flagged as being a potential false sample. If more than a set number of potentially false samples are obtained, the power converter may enter an auto-restart mode. | 04-04-2013 |
20130083566 | MULTI-STAGE SAMPLING CIRCUIT FOR A POWER CONVERTER CONTROLLER - An example controller for a power converter includes a track and hold circuit, a sample and hold circuit, and drive logic. The track and hold circuit receives a signal from a terminal of the controller that is representative of an output voltage of the power converter. The track and hold circuit includes a first capacitor that provides a first voltage that tracks the signal and then holds the first voltage. The sample and hold circuit samples the first voltage when the first voltage is held on the first capacitor. The sample and hold circuit includes a second capacitor coupled to hold a second voltage representative of the first voltage after a sample period, where the second capacitor has a capacitance value larger than that of the first capacitor. The drive logic controls the first switch to regulate an output of the power converter in response to the second voltage. | 04-04-2013 |
20130083565 | ON TIME SAMPLING PREVENTION - An example controller for a power converter includes a feedback sampling circuit, drive logic and a false sampling prevention circuit. The feedback sampling circuit is coupled to sample a feedback signal received from a terminal of the controller and to generate a sample signal representative of a value of the feedback signal. The drive logic is coupled to the feedback sampling circuit and coupled to control the power switch to regulate an output of the power converter in response to the sample signal. The false sampling prevention circuit is coupled to receive a sampling complete signal that indicates when the sampling of the feedback signal is complete. The false sampling prevention circuit is further coupled to the drive logic to extend the off time of the power switch until the sampling complete signal indicates that the sampling of the feedback signal by the feedback sampling circuit is complete. | 04-04-2013 |
20130077358 | CONTROLLER WITH CONSTANT CURRENT LIMIT - Methods and apparatuses are disclosed for generating a temperature independent current limit. The value of the temperature independent current limit may be determined based in part on an error signal representative of a difference between an actual output value and a desired output value of a power converter. When the error signal is below a lower threshold voltage, the temperature independent current limit may be set to a first value. When the error signal is above an upper threshold voltage, the temperature independent current limit may be set to a second, higher value. When the error signal is between the lower threshold voltage and the upper threshold voltage, the temperature independent current limit may change linearly with the error signal. The error signal may be adjusted to compensate for changes in the system caused by a change in temperature. | 03-28-2013 |
20130077357 | ADAPTIVE BIASING FOR INTEGRATED CIRCUITS - Methods and apparatuses are disclosed for generating an adjustable bias current. The value of the adjustable bias current may be determined based in part on an error signal representative of a difference between an actual output value and a desired output value of a power converter. When the error signal is below a lower threshold voltage, the adjustable bias current may be set to a first value. When the error signal is above an upper threshold voltage, the adjustable bias current may be set to a second, higher value. When the error signal is between the lower threshold voltage and the upper threshold voltage, the adjustable bias current may change linearly with the error signal. | 03-28-2013 |
20130077355 | APPARATUS AND METHOD FOR DETECTING A CHANGE IN OUTPUT VOLTAGE OF AN ISOLATED POWER CONVERTER - A power converter controller includes a drive circuit coupled to control switching of a power switch coupled to an energy transfer element and an input of the power converter. An output voltage sensor including first and second pulse sampler circuits is coupled to capture first and second peak voltages, respectively, that are representative of a second peak of a ringing voltage of a feedback signal representative of an output of the power converter. The first pulse sampler circuit is coupled to capture the first peak voltage at a first time in the feedback signal. The second pulse sampler circuit is coupled to capture the second peak voltage at a second time in the feedback signal. The drive circuit is coupled to receive a change signal from the output voltage sensor in response to the first and second peak voltages. | 03-28-2013 |
20130077350 | POWER SUPPLY CONTROLLER WITH MINIMUM-SUM MULTI-CYCLE MODULATION - An example power supply controller includes a signal separator circuit that generates a feedback signal. An error signal generator generates an error signal in response to the feedback signal. A control circuit generates a drive signal in response to the error signal. The drive signal controls switching of a switch. A multi-cycle modulation circuit is included in the control circuit and generates a skip signal in response to a start skip signal, a stop skip signal and a skip mask signal. The skip mask signal is generated in response to the skip signal. The start skip and stop skip signals cause the drive signal to start skipping or stop skipping, respectively, on-time intervals of cycles. The skip mask signal disables the start skip signal from causing the drive signal to start skipping the on-time intervals of cycles. | 03-28-2013 |
20130070488 | Power Supply Circuit with a Control Terminal for Different Functional Modes of Operation - A method of operation for flyback power converter includes operating a controller of the flyback power converter in a regulation mode when a control signal is below a first threshold. The control signal is provided as an input to a terminal of the flyback power converter. When the control signal is below a second threshold and above the first threshold, the controller is operated in a limiting mode. The controller is operated in an external command mode when the control signal is below a third threshold and above the second threshold. Lastly, when the control signal is above the third threshold, the controller is operated in a protection mode. | 03-21-2013 |
20130058182 | Method and Apparatus for Programming an Anti-Fuse Element in a High-Voltage Integrated Circuit - A method for programming a programmable block of a power IC device includes selecting an anti-fuse element of the programmable block to be programmed. The anti-fuse element includes first and second capacitive plates separated by a dielectric layer. A voltage pulse is then applied to a pin of the power IC device. The pin is connected to a drain of a high-voltage field-effect transistor (HVFET) that drives an external load via the pin during a normal operating mode of the power IC device. The voltage pulse, which is coupled to the first capacitive plate of the anti-fuse element, has a potential sufficiently high to cause a current to flow through the anti-fuse element that destroys at least a portion of the dielectric layer, thereby electrically shorting the first and second capacitive plates | 03-07-2013 |
20130057167 | DAMPER CIRCUIT FOR SWITCHED DIMMING - A power converter includes dimmer circuit, a rectifier circuit, and a thyristor damper circuit. The dimmer circuit provides a dimmer voltage in response to an input voltage. The rectifier circuit provides a rectified voltage in response to the dimmer voltage. The thyristor damper circuit dampens an input current associated with the rectified voltage based on the input current and ceases dampening the rectified voltage based on the rectified voltage. | 03-07-2013 |
20130051093 | METHOD AND APPARATUS FOR VARYING CURRENT LIMIT TO LIMIT AN OUTPUT POWER OF A POWER SUPPLY - A power supply controller includes an input voltage sense input and an output voltage sense input coupled to sense an input voltage and an output voltage of a power supply. A current limit circuit includes a first variable resistance coupled in parallel with a second variable resistance. The first variable resistance responsive the input voltage of the power supply and the second variable resistance is responsive to the output voltage of the power supply. The current limit circuit is coupled to generate a current limit signal in response to an equivalent resistance of the first variable resistance coupled in parallel with the second variable resistance. A drive signal generator is coupled to generate a drive signal in response to the current limit signal to drive a power switch of the power supply to limit an output power of the power supply in response to the input voltage. | 02-28-2013 |
20130043487 | LAYOUT DESIGN FOR A HIGH POWER, GaN-BASED FET - A FET includes a first and second set of finger arrays that each include a source, gate and drain. A first source pad is electrically coupled to source electrodes in the first set of finger arrays. A second source pad is electrically coupled to the source electrodes in the second set of finger arrays. A common drain pad is electrically coupled to drain electrodes in the first and second set of finger arrays. A first gate pad is electrically coupled to gate electrodes in the first set of finger arrays. A second gate pad is electrically coupled to gate electrodes in the second set of finger arrays. A substrate is also provided on which are disposed the first and second set of finger arrays, the first and second source pads, the common drain pad, and the first and second gate pads. | 02-21-2013 |
20130033902 | SMOOTH MODE TRANSITION PLATEAU FOR A POWER SUPPLY CONTROLLER - A power converter controller is disclosed. An example controller includes a drive signal generator coupled to generate a drive signal to control a switching of a power switch to control a transfer of energy from an input of a power supply to an output of the power supply. A feedback circuit is coupled to receive a feedback signal representative of the output of the power supply. The feedback circuit coupled to generate a control signal in response to the feedback signal. An oscillator circuit is coupled to generate an oscillating signal in response to the control signal. The drive signal generator is coupled to generate the drive signal in response to the oscillating signal. A frequency of the oscillating signal increases from a first frequency to a second frequency with respect to the control signal for a first range of control signal values. The frequency of the oscillating signal remains substantially equal to the second frequency for a second range of control signal values. The frequency of the oscillating signal decreases from the second frequency to a third frequency with respect to the control signal for a third range of control signal values. The first range of control signal values is less than the second range of control signal values and the second range of control signal values is less than the third range of control signal values. | 02-07-2013 |
20130027996 | VARIABLE FREQUENCY TIMING CIRCUIT FOR A POWER SUPPLY CONTROL CIRCUIT - An example integrated circuit controller includes a pulse width modulation (PWM) circuit and a timing circuit. The PWM circuit controls a switch to regulate an output of a power supply in response to a switch current flowing through the switch and in response to a clock signal having a switching period. The timing circuit provides the clock signal and includes a timing capacitor where the switching period of the clock signal is equal to a charging time that the timing capacitor charges to an upper reference voltage plus a discharging time that the timing capacitor discharges to a lower reference voltage. The timing circuit increases the charging time of the timing capacitor by decreasing a rate at which the timing capacitor is charged to increase the switching period of the clock signal if an on time of the switch is greater than or equal to a threshold time. | 01-31-2013 |
20130027991 | METHOD AND APPARATUS TO CONTROL A POWER CONVERTER HAVING A LOW LOOP BANDWIDTH - An example controller includes a comparator coupled to receive a feedback signal representative of an output of the power converter. A counter is coupled to receive an output of the comparator and a feedback sampling signal. The counter is coupled to sample the output of the comparator in response to the feedback sampling signal. A state machine is coupled to receive a feedback time period signal. The state machine is coupled to control switching of the power converter according to one of a plurality of operating conditions in response to the counter and the feedback time period signal. A period of the feedback time period signal is substantially greater than a period of the feedback sampling signal. The state machine is coupled to be updated in response to the feedback time period signal. | 01-31-2013 |
20130027990 | VARYING SWITCHING FREQUENCY AND PERIOD OF A POWER SUPPLY CONTROLLER - An example integrated circuit controller for use in a switching power supply includes a pulse width modulation (PWM) circuit and a timing circuit. The PWM circuit controls a switch to regulate an output of the power supply in response to a switch current flowing through the switch and in response to a clock signal having a switching period. The timing circuit provides the clock signal and increases the switching period in response to an on time of the switch exceeding a threshold time. | 01-31-2013 |
20130027815 | ADJACENT TERMINAL FAULT DETECTION - This relates to detecting unwanted couplings between a protected terminal and other terminals in an integrated controller of a power supply. Offset and clamp circuitry may apply a positive or negative offset voltage and clamp current to one or more terminals of the controller. In the event that a terminal having the offset voltage and clamp current is accidentally coupled to the protected terminal, the offset voltage and clamp current may be applied to the protected terminal. The protected terminal may be coupled to a fault detection circuitry operable to detect a fault signal at the protected terminal. The fault detection circuitry of the controller may cause the power supply to shut down in response to a detection of the fault signal at the protected terminal or may cause the power supply to shut down in response to a detection of a predefined threshold number of cycles in which the fault signal is detected. | 01-31-2013 |
20130027151 | PULSE WIDTH MODULATOR WITH TWO-WAY INTEGRATOR - An example PWM includes a driver and a two-way oscillator. The oscillator includes, a first frequency adjust current source, a second frequency adjust current source, a capacitor, a switching reference and a comparator. The capacitor integrates a frequency adjust current by charging with the first frequency adjust current source. The capacitor subsequently integrates a second frequency adjust current by discharging with the second frequency adjust current source. The switching reference outputs a first reference voltage and a second reference voltage responsive to an oscillator signal. The comparator compares the output of the switching reference with a voltage on the capacitor. The first and second frequency adjust current sources vary the first and second frequency adjust currents to vary the frequency of the PWM signal to spread energy of switching harmonics over a frequency band and to reduce EMI. | 01-31-2013 |
20130027014 | POWER SUPPLY CONTROLLER WITH AN INPUT VOLTAGE COMPENSATION CIRCUIT - An example controller for a power supply includes a drive signal generator and a compensation circuit. The drive signal generator is to be coupled to control switching of a switch included in the power supply to regulate an output voltage of the power supply in response to a sensed output voltage such that the output voltage of the power supply is greater than an input voltage of the power supply. The compensation circuit is coupled to the drive signal generator and is also coupled to output an offset current to adjust the sensed output voltage in response to the input voltage of the power supply. | 01-31-2013 |
20130021828 | INTEGRATED ON-TIME EXTENSION FOR NON-DISSIPATIVE BLEEDING IN A POWER SUPPLY - An example controller for a switched mode power supply includes a comparator, a drive logic, and an on-time extension block. The comparator has an output indicating whether the current through a switch of the power supply exceeds a zero-crossing current threshold. The drive logic is to generate a drive logic output signal in response to the current sense signal and in response to a feedback signal, where the drive logic output signal is representative of an on-time of the switch to regulate the output of the power supply. The on-time extension block is coupled to control switching of a switch and to extend the on-time until the output of the comparator indicates that the current sense signal reaches the zero-crossing current threshold or until the on-time of the switch reaches a zero-crossing time threshold. | 01-24-2013 |
20130021014 | METHOD AND APPARATUS FOR IMPLEMENTING SLEW RATE CONTROL USING BYPASS CAPACITOR - An example circuit includes a capacitance circuit coupled between a first node and a second node. A regulator circuit is coupled to the capacitance circuit to regulate a supply voltage across the capacitance circuit with a charge current during a normal operation mode of the circuit. A slew rate control circuit is coupled to the capacitance circuit and the regulator circuit. The slew rate control circuit is coupled to set a slew rate of a change in voltage over change in time between the first and second nodes during a power up mode of the circuit. The slew rate control circuit includes a transistor coupled between the first and second nodes to shunt excess current from the charge current. | 01-24-2013 |
20130021005 | SINGLE-STAGE POWER SUPPLY WITH POWER FACTOR CORRECTION AND CONSTANT CURRENT OUTPUT - An example controller for providing power factor correction and a constant current output in a power supply includes a means for generating a delayed ramp signal and a means for integrating an input current sense signal representative of an input current and for generating an input charge signal in response thereto. The controller also includes a means for determining a ratio of an input voltage sense signal to an output voltage sense signal and for generating an input charge control signal responsive to the input charge signal and the ratio of the input voltage sense signal to the output voltage sense signal. A means for comparing the input charge control signal to the delayed ramp signal to generate a drive signal to control a switch of the power supply is also included. | 01-24-2013 |
20130020965 | POWER CONVERTER WITH COMPENSATION CIRCUIT FOR ADJUSTING OUTPUT CURRENT PROVIDED TO A CONSTANT LOAD - A power converter for constant loads includes an energy transfer element, a switch, a controller, and a compensation circuit. The energy transfer element is coupled to receive a rectified voltage having a blocked portion that corresponds to a phase angle. The controller is coupled to control switching of the switch to regulate an output current of the power converter in response to a plurality of signals. The plurality of signals includes a peak input voltage signal and a feedback signal. The compensation circuit is coupled to output a compensation signal to adjust at least one of the plurality of signals in response to the phase angle exceeding a phase angle threshold. The compensation circuit does not output the compensation signal and does not adjust the at least one of the plurality of signals when the phase angle is less than the phase angle threshold. | 01-24-2013 |
20120326697 | Temperature Independent Reference Circuit - A temperature independent reference circuit includes first and second bipolar transistors with commonly coupled bases. First and second resistors are coupled in series between the emitter of the second bipolar transistor and ground. The first and second resistors have first and second resistance values, R | 12-27-2012 |
20120320640 | METHOD AND APPARATUS FOR PROGRAMMING A POWER CONVERTER CONTROLLER WITH AN EXTERNAL PROGRAMMING TERMINAL HAVING MULTIPLE FUNCTIONS - A power converter controller is disclosed. An example controller includes a control circuit coupled to receive a feedback signal representative of an output of the power converter. The control circuit coupled to control a switching of a power switch of the power converter in response to the feedback signal to control a transfer of energy from an input of the power converter to the output of the power converter. An internal programming interface circuit is coupled to the control circuit. A coupling switcher is coupled to the internal programming interface circuit. An external programming terminal is selectively coupled to the internal programming interface circuit through the coupling switcher. An external programming circuit coupled to the external programming terminal is coupled to the internal programming interface circuit through the coupling switcher during a startup programming condition and during a fault condition of the power converter. The external programming circuit that is coupled to the external programming terminal is decoupled from the internal programming interface circuit by the coupling switcher during a normal operating condition of the power converter. | 12-20-2012 |
20120320639 | METHOD AND APPARATUS TO SELECT A PARAMETER/MODE BASED ON A MEASUREMENT DURING AN INITIALIZATION PERIOD - A power supply includes an energy transfer element coupled between an input and an output. A switch is coupled to an input of the energy transfer element. A threshold detection circuit includes in an integrated circuit coupled to measure a signal from a resistive external circuit coupled between fourth and first external terminals of the integrated circuit during an initialization period after the fourth external terminal has been charged to a supply threshold value. A regulator circuit is coupled between second and fourth external terminals of the integrated circuit. The regulator circuit is coupled to charge the fourth external terminal to the supply threshold value during the initialization period. A selection circuit is coupled to the threshold detection circuit to select a parameter/mode of the integrated circuit in response to the measured signal. | 12-20-2012 |
20120320634 | METHOD AND APPARATUS FOR A CONTROL CIRCUIT WITH MULTIPLE OPERATING MODES - An example controller for use in a power converter includes an oscillator that is to be coupled to a switch of the power converter to determine a switching cycle period of the switch. The controller also includes means for controlling a duty cycle of the switch to regulate an output of the power converter and for maintaining a substantially constant rate of change of the duty cycle with respect to changes in a magnitude of a feedback signal as the controller transitions between duty cycle control modes such that a control loop gain of the power converter is substantially constant during the transition. | 12-20-2012 |
20120319744 | METHOD AND APPARATUS FOR SIMPLIFYING THE CONTROL OF A SWITCH - A half bridge converter includes a transformer with a high side switch coupled between a first input terminal and a primary winding of the transformer. A low side switch is coupled between a second input terminal and the primary winding. A first control circuit is coupled to the first input terminal and the primary winding to control the high side switch in response to a rate of voltage change with respect to time across the high side switch while the high side switch is off. A second control circuit coupled to the primary winding and the second input terminal to control the low side switch in response to a rate of voltage change with respect to time across the low side switch while the low side switch is off. | 12-20-2012 |
20120314457 | CONTROL ARRANGEMENT FOR A RESONANT MODE POWER CONVERTER - A resonant mode converter includes a PFC power converter having an input coupled to receive an input voltage. An LLC power converter is cascaded with the PFC power converter. The LLC power converter includes a transformer coupled to generate an output of the resonant mode converter. A feedback circuit is coupled to generate a first current representative of the output of the resonant mode converter. A control unit includes a current limiting circuit coupled to receive the first current and a second current generated in response to a reference voltage. The current limiting circuit is coupled to limit the first current in response to the second current. The control unit further includes an oscillator coupled to generate a control signal having a control frequency in response to the first current. The resonant mode converter output is controlled in response to the control frequency. | 12-13-2012 |
20120314453 | ELECTRONIC CIRCUIT CONTROL ELEMENT WITH TAP ELEMENT - An example control element for use in a power supply includes a high-voltage transistor and a control circuit to control switching of the high-voltage transistor. The high-voltage transistor includes a drain region, source region, tap region, drift region, and tap drift region, all of a first conductivity type. The transistor also includes a body region of a second conductivity type. An insulated gate is included in the transistor such that when the insulated gate is biased a channel is formed across the body region to form a conduction path between the source region and the drift region. A voltage at the tap region with respect to the source region is substantially constant and less than a voltage at the drain region with respect to the source region in response to the voltage at the drain region exceeding a pinch off voltage. | 12-13-2012 |
20120313140 | Method of Fabricating a Deep Trench Insulated Gate Bipolar Transistor - In one embodiment, a method comprises forming an epitaxial layer over a substrate of an opposite conductivity type, the epitaxial layer being separated by a buffer layer having a doping concentration that is substantially constant in a vertical direction down to the buffer layer. A pair of spaced-apart trenches is formed in the epitaxial layer from a top surface of the epitaxial layer down at least into the buffer layer. A dielectric material is formed in the trenches over the first and second sidewall portions. Source/collector and body regions of are formed at the top of the epitaxial layer, the body region separating the source/collector region of the pillar from a drift region of the epitaxial layer that extends from the body region to the buffer layer. An insulated gate member is then formed in each of the trenches adjacent to and insulated from the body region. | 12-13-2012 |
20120306012 | Power Integrated Circuit Device With Incorporated Sense FET - In one embodiment, a power integrated circuit device includes a main lateral high-voltage field-effect transistor (HVFET) and an adjacently-located lateral sense FET, both of which are formed on a high-resistivity substrate. A sense resistor is formed in a well region disposed in an area of the substrate between the HVFET and the sense FET. A parasitic substrate resistor is formed in parallel electrical connection with the sense resistor between the source regions of the HVFET and the sense FET. Both transistor devices share common drain and gate electrodes. When the main lateral HVFET and the sense FET are in an on-state, a voltage potential is produced at the second source metal layer that is proportional to a first current flowing through the lateral HVFET. | 12-06-2012 |
20120281439 | FLYBACK POWER SUPPLY WITH FORCED PRIMARY REGULATION - A power supply includes an energy transfer element having first, second and third windings. An input of the first winding is coupled to an input of the power supply and an output of the second winding is coupled to an output of the power supply. A secondary control circuit is coupled across the second winding to switch a switched element coupled to the second winding in response to a difference between an actual output value and a desired output value to force a current in the third winding that is representative of the difference between the actual output value and the desired output value. A primary control circuit is coupled to a primary switch and to the third winding. The primary control circuit is coupled to switch the primary switch in response to the current forced in the third winding by the secondary control circuit. | 11-08-2012 |
20120280734 | METHOD AND APPARATUS FOR PULSE WIDTH MODULATION - An integrated control circuit according to aspects of the present invention includes an oscillator, a capacitor, and a logic gate. The oscillator generates a periodic timing signal that cycles between a first logic state for a first time duration and a second logic state for a second time duration. The capacitor receives a charge current in response to the periodic timing signal transitioning to the first logic state, where a voltage on the capacitor increases for the first time duration to an initial value. The logic gate generates a periodic output signal having a duty ratio that is responsive to a time that it takes the capacitor to discharge from the initial value to a reference voltage. A period of the periodic output signal is the period of the periodic timing signal. | 11-08-2012 |
20120280670 | OFF-LINE CONVERTER WITH DIGITAL CONTROL - A power converter includes an input and an output. A regulation circuit is coupled between the power converter input and the power converter output. The regulation circuit is coupled to receive a feedback signal representative of the power converter output. The feedback signal has a first feedback state that represents a level at the power converter output that is above a threshold level and a second feedback state that represents a level at the power converter output that is below the threshold level. An oscillator is included in the regulation circuit that provides an oscillation signal that cycles between two states. The regulation circuit is coupled to be responsive to the oscillation signal and to a change between the first and second feedback states to enable or disable a flow of energy from the power converter input to the power converter output. | 11-08-2012 |
20120280666 | METHOD AND APPARATUS FOR A CONTROL CIRCUIT RESPONSIVE TO AN IMPEDANCE COUPLED TO A CONTROL CIRCUIT TERMINAL - A method, in a power supply controller, of responding to an increase in current through a terminal of the power supply controller, is disclosed. The method includes regulating the terminal to a first voltage level and sensing a magnitude of a first current through the terminal while the controller is regulating the terminal to the first voltage level. The method also includes providing an initial response by the power supply controller in response to the magnitude of the first current exceeding a first threshold current level and then regulating the terminal to a second voltage level after the magnitude of the first current exceeds the first threshold current level. The magnitude of a second current through the terminal is sensed while the controller is regulating the terminal to the second voltage level and the controller determines a final response based on the magnitude of the second current. | 11-08-2012 |
20120280629 | DIMMING CONTROL FOR A SWITCHING POWER SUPPLY - A switching power supply includes a switch and a controller for dimming control of the switching power supply. The controller includes a phase angle measurement block and a drive logic block. The phase angle measurement block is coupled to receive an input sense signal. The phase angle measurement block generates a phase angle signal representative of a phase angle of an input voltage of the power supply in response to the input sense signal. The drive logic block is coupled to control switching of the switch. The drive logic block controls the switch in a closed loop dimming control when the phase angle is less than or equal to a phase threshold and in a open loop dimming control when the phase angle is greater than the phase threshold. | 11-08-2012 |
20120280314 | Gate Pullback at Ends of High-Voltage Vertical Transistor Structure - In one embodiment, a transistor includes a pillar of semiconductor material arranged in a racetrack-shaped layout having a substantially linear section that extends in a first lateral direction and rounded sections at each end of the substantially linear section. First and second dielectric regions are disposed on opposite sides of the pillar. First and second field plates are respectively disposed in the first and second dielectric regions. First and second gate members respectively disposed in the first and second dielectric regions are separated from the pillar by a gate oxide having a first thickness in the substantially linear section. The gate oxide being substantially thicker at the rounded sections. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. | 11-08-2012 |
20120274298 | POWER FACTOR CORRECTION CONVERTER CONTROL OFFSET - A power supply arrangement includes a PFC converter, an LLC converter, a control unit and an offset unit. The control unit generates a control signal to control a duty cycle of a PWM (Pulse Width Modulation) signal to control the PFC converter. The control unit includes a PWM converter that generates the PWM signal to which a switching circuit is responsive to switch a current representing an input current of the PFC converter. An amplifier receives a current sense signal and provides the current representing the input current of the PFC converter. An offset unit generates a variable offset signal to offset the control signal or a signal used by the control unit to generate the control signal. The variable offset signal is an offset current coupled to offset the current sense signal received at the input of the amplifier. | 11-01-2012 |
20120273944 | Power Semiconductor Package With Bottom Surface Protrusions - A package includes a body that encapsulates a semiconductor die, the body having a first pair of opposing lateral sides, a second pair of opposing lateral sides, a top, and a bottom. The bottom has a primary surface and a plurality of protrusions that extend outward from the primary surface. When the package is mounted to a printed circuit board (PCB) the protrusions contact the PCB and the primary surface is disposed a first distance away from the PCB. The package further includes a plurality of leads that extend outward from the first pair of opposing lateral sides. | 11-01-2012 |
20120273885 | High-Voltage Transistor Structure with Reduced Gate Capacitance - In one embodiment, a high voltage field-effect transistor (HVFET) includes a field oxide layer that covers a first well region, the field oxide layer having a first thickness and extending in a second lateral direction from a drain region to near a second well region. A gate oxide covers a channel region and has a second dimension in a first lateral direction. A gate extends in the second lateral direction from the source region to over a portion of the field oxide layer, the gate being insulated from the channel region by the gate oxide, the gate extending in the first lateral dimension over an inactive area of the HVFET beyond the second dimension of the gate oxide, the gate being insulated from the first and second well regions over the inactive area by the field oxide layer. | 11-01-2012 |
20120262954 | OFF LINE RESONANT CONVERTER WITH MERGED LINE RECTIFICATION AND POWER FACTOR CORRECTION - An off line resonant converter with improved power factor and merged line rectification is disclosed. An example off line resonant converter includes a boost storage inductance circuit to be coupled to receive an ac input line voltage. A switcher circuit is coupled to the boost storage inductance circuit. The switcher circuit includes stacked first and second passive switching devices coupled to the boost storage inductance circuit. The switcher circuit further includes stacked first and second active bidirectional switching devices coupled to the stacked first and second passive switching devices. The stacked first and second active bidirectional switching devices are controlled to generate a square wave signal and to alternately store energy in and receive energy from the boost storage inductance circuit such that a pulsating current is conducted between the boost storage inductance circuit and the switcher circuit. The pulsating current is bidirectional and flows in a first direction when the ac input line voltage is at a first polarity. The pulsating current flows in an opposite second direction when the ac input line voltage is at a second polarity. A resonant circuit is coupled to an output of the switcher circuit to receive the square wave signal from the switcher circuit to generate an output of the resonant converter. | 10-18-2012 |
20120262895 | LOW-COST TRANSFORMER ASSEMBLY - A transformer assembly is disclosed. An example circuit board assembly includes a circuit board. A drum core inductor is also included and has a drum core, a first winding, and first and second terminals extending from a first end of the drum core inductor. A wire of the first winding is wound around an axis of the drum core. The first winding has first and second ends coupled to the first and second terminals of the drum core inductor, respectively. A bobbin has first and second terminals extending from a first end of the bobbin. A wire of a second winding is wound around an axis of the bobbin. The second winding has first and second ends coupled to the first and second terminals of the bobbin, respectively. The first ends of the drum core inductor and the bobbin are attached to a circuit board such that the drum core inductor is positioned on the circuit board inside an opening of the bobbin defined along the axis of the bobbin. The drum core inductor and the bobbin are detached from one another. | 10-18-2012 |
20120250368 | POWER SUPPLY CONTROLLER WITH INPUT VOLTAGE COMPENSATION FOR EFFICIENCY AND MAXIMUM POWER OUTPUT - A controller for regulating an output of a power supply includes a logic block and an oscillator. The logic block generates the drive signal to control switching of a power switch in response to a clock signal. The clock signal has a frequency that decreases responsive to a time period of the drive signal, where a decrease in the time period of the drive signal represents an increase in an input voltage of the power supply. The oscillator is coupled to generate the clock signal in response to a waveform having an amplitude swing. The oscillator alters the waveform in response to the time period of the drive signal. | 10-04-2012 |
20120250364 | FLYBACK CONVERTER WITH FORWARD CONVERTER RESET CLAMP - A power supply includes a first power converter having a first transformer coupled to an input of the power supply and to a first output of the power supply. A clamp reset circuit is coupled to the first transformer. The clamp reset circuit includes a capacitor coupled to the first power converter and a Zener diode coupled to the capacitor. A second power converter is coupled to the clamp reset circuit. The second power converter includes a second transformer coupled to the clamp circuit and to a second output of the power supply. The capacitor is coupled to store energy received from the first power converter and the second power converter. The Zener diode is coupled to prevent the energy received from the first power converter and the second power converter from exceeding a threshold. The Zener diode limits voltage on the capacitor. | 10-04-2012 |
20120250360 | LLC CONTROLLER WITH PROGRAMMABLE FRACTIONAL BURST FREQUENCY - A controller for use in an LLC resonant converter is disclosed. An example controller is controlled by detecting a maximum frequency signal to set a maximum switching frequency of the LLC resonant converter. A burst stop frequency and a burst start frequency are programmed in response to the maximum switching frequency. The burst stop frequency and the burst start frequency are fractions of the maximum switching frequency. The LLC resonant converter is switched in response to a feedback signal to regulate an output of the LLC resonant converter. The steps of switching the LLC resonant converter in a burst mode in response to the feedback signal reaching a value corresponding to the programmed burst start frequency and of stopping the switching of the LLC resonant converter in the burst mode in response to the feedback signal reaching a value corresponding to the programmed burst stop frequency are repeated. | 10-04-2012 |
20120246495 | METHOD AND APPARATUS TO AUTHENTICATE A POWER SUPPLY - A power bus monitor for use in an electronic product is coupled to receive power from an external power supply. The power bus monitor includes a signal detector coupled to an output of the external power supply to receive and demodulate information encoded on the output of the external power supply into a sequence of bits. A decoder is coupled to receive the sequence of bits from the signal detector and decrypt the sequence of bits. A logical comparator is coupled to receive the sequence of bits decrypted by the decoder. The logical comparator is coupled to assert an authentication signal indicating the external power supply is authorized to provide power to the electronic product when the logical comparator recognizes the sequence of bits decrypted by the decoder as a key. | 09-27-2012 |
20120243277 | METHOD AND APPARATUS TO REDUCE LINE CURRENT HARMONICS FROM A POWER SUPPLY - In one aspect, a power converter includes a power switch, an energy storage element, a driver, a first calculator, and a second calculator. The first calculator coupled to determine an end of an on time of a power switch of the power converter by integrating an input current to output an on time signal representative of the end of the on time of the power switch. The second calculator coupled to determine an end of an off time of the power switch by integrating a difference between an input voltage and an output voltage to output an off time signal representative of the end of the off time of the power switch. The driver controls the power switch such that an input current of the power converter is substantially proportional to an input voltage of the power converter in response to the on time signal and the off time signal. | 09-27-2012 |
20120243266 | METHOD AND APPARATUS FOR HIGH-SIDE INPUT WINDING REGULATION - A controller for use in a power converter includes a control circuit coupled to control switching of a power switch coupled between a positive input supply rail of the power converter and an energy transfer element input of the power converter. A sampling circuit is coupled to the control circuit and is coupled to receive a signal across the energy transfer element input during an off time of the power switch to provide a sampled output of the converter. The sampled output of the power converter is disabled from being resampled by the sampling circuit during an on time of the power switch. A switch conduction scheduling circuit is included in the control circuit and is coupled to the sampling circuit such that the control circuit is coupled to switch the power switch in response to the sampled output of the power converter. | 09-27-2012 |
20120238063 | Termination and Contact Structures for a High Voltage Gan-Based Heterojunction Transistor - A semiconductor device is provided that includes a substrate, a first active layer disposed over the substrate, and a second active layer disposed on the first active layer. The second active layer has a higher bandgap than the first active layer such that a two-dimensional electron gas layer arises between the first active layer and the second active layer. A termination layer, which is disposed on the second active layer, includes InGaN. Source, gate and drain contacts are disposed on the termination layer. | 09-20-2012 |
20120224399 | METHOD AND APPARATUS TO REDUCE AUDIO FREQUENCIES IN A SWITCHING POWER SUPPLY - An example controller for use in a power supply regulator includes a switch signal generator, a modulation circuit, and a multi-cycle modulator circuit. The modulation circuit modulates the period of a modulation switching signal when an equivalent switching frequency is greater than a reference frequency and fixes the switching period when the equivalent switching frequency is less than the reference frequency. The multi-cycle modulator circuit enables the switch signal generator to provide a switch signal uninterrupted if the equivalent switching frequency is greater than the reference frequency and disables the switch signal generator for a first time period and then enables the switch signal generator for a second time period when the equivalent frequency is less than the reference frequency. The multi-cycle modulator circuit varies the first time period to regulate the output. | 09-06-2012 |
20120223799 | TRANSVERSE SHROUD AND BOBBIN ASSEMBLY - A transformer assembly includes a vertical bobbin and a shrouding element. The vertical bobbin includes a first winding portion, a second winding portion, and a flange. The flange is disposed between the first winding portion and the second winding portion. The flange includes a flange edge. The shrouding element, which substantially covers the first winding portion or the second winding portion, includes a shrouding edge that is operatively coupled to the flange edge. The flange edge and the shrouding edge have at least one complementary corrugation. In one example, the flange edge includes at least one groove and the shrouding edge includes at least one protrusion that is complementary to the groove. In another example, the shrouding edge includes at least one groove and the flange edge includes at least one protrusion that is complementary to the groove. | 09-06-2012 |
20120223795 | SHROUD FOR BOBBIN - A shroud includes a shrouding element and a window. The shrouding element is adapted to substantially cover either a first winding portion or a second winding portion of a vertical bobbin. The window, which is formed in the shrouding element, allows access to the first winding portion or the second winding portion (whichever is substantially covered by the shrouding element) through the shrouding element. The vertical bobbin has electrical terminals on a single end of its center axis and is designed to lie perpendicular to the PCB. | 09-06-2012 |
20120223746 | METHOD AND APPARATUS SWITCHING A SEMICONDUCTOR SWITCH WITH A MULTI-STAGE DRIVE CIRCUIT - A multi-stage drive circuit is to be coupled to a semiconductor switch having a drive terminal, a first terminal and a second terminal, to switch the semiconductor switch on and off. The multi-stage drive circuit includes a first drive circuit, a second drive circuit and a selector circuit. The first drive circuit is to be coupled to provide a first drive signal to the drive terminal of the semiconductor switch and the second drive circuit is to be coupled to provide a second drive signal to the drive terminal of the semiconductor switch. The selector circuit is to be coupled to turn on the first and second drive circuits to provide the first and second drive signals to the drive terminal, respectively. The selector circuit turns on the second drive circuit responsive to a voltage between the first and second terminals of the semiconductor switch falling to a threshold value. | 09-06-2012 |
20120218788 | METHOD AND APPARATUS FOR DIGITAL CONTROL OF A SWITCHING REGULATOR - In one aspect, a power supply includes an energy transfer element, a switch, a feedback circuit, a comparator, a state machine, and a control circuit. The feedback circuit generates a feedback signal representative of an output level of the power supply. The comparator provides a feedback state signal having a first feedback state that represents the output level of the power supply being above a threshold level and a second feedback state that represents the output level being below the threshold level. The state machine selectively modulates a first signal in response to the feedback state signal, where the first signal is the feedback signal or the threshold value signal. The control circuit is coupled to control switching of the switch to regulate the output level of the power supply in response to the feedback state signal. | 08-30-2012 |
20120218786 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH AN EVENT COUNTER IN A POWER CONVERTER - An example power converter includes an energy transfer element, a switch, and a control circuit. The control circuit includes a drive signal generator and an unregulated dormant mode control circuit. The unregulated dormant mode control circuit renders dormant the drive signal generator thereby ceasing the regulation of the output by the drive signal generator when the energy requirement of the one or more loads falls below a threshold for more than a first period of time. The drive signal generator is unresponsive to changes in the energy requirements of the one or more loads when dormant. The unregulated dormant mode control circuit powers up the drive signal generator after a second period of time has elapsed, such that the drive signal generator is again responsive to changes in the energy requirement of the one or more loads after the second period of time has elapsed. | 08-30-2012 |
20120218784 | DC CONVERTER WITH INDEPENDENTLY CONTROLLED OUTPUTS - A controller for use in a power supply includes a clock coupled to output a clock signal. The clock signal determines a frequency. A modulator is coupled to receive the clock signal. The clock signal is divided into N cycles within the power supply. N is an integer greater than one. The modulator is coupled to receive N feedback signals from N output circuits during each respective one of the N cycles to control conduction times of a primary switch during each respective one of the N cycles to regulate N outputs of a power supply. Each of the N feedback signals is representative of a respective one of N output voltages of a respective to one of the N outputs of the power supply. | 08-30-2012 |
20120206842 | FAULT CONDITION PROTECTION - A switched mode power supply includes a transformer and an integrated circuit regulator. The integrated circuit regulator is coupled to the transformer and includes switching regulator logic, a counter, and a switching transistor. The regulator logic generates a switching signal in response to the feedback signal. The counter receives the feedback signal, where the feedback signal periodically cycles between a first state and a second state when the switched mode power supply operates normally. An output of the counter indicates an auto-restart mode of the regulator in response to the feedback signal remaining in the first state for a predetermined count due to a fault condition. The switching transistor is coupled to be turned on and off in response to the switching signal when the output of the counter does not indicate the auto-restart mode and is disabled when the output of the counter indicates the auto-restart mode. | 08-16-2012 |
20120199885 | Integrated Transistor and Anti-Fuse Programming Element for a High-Voltage Integrated Circuit - A semiconductor device includes an N type well region in a P type substrate. A source region of a MOSFET is laterally separated from a boundary of the well region, which includes the drain of the MOSFET. An insulated gate of the MOSFET extends laterally from the source region to at least just past the boundary of the well region. A polysilicon layer, which forms a first plate of a capacitive anti-fuse, is insulated from an area of the well region, which forms the second plate of the anti-fuse. The anti-fuse is programmed by application of a voltage across the first and second capacitive plates sufficient to destroy at least a portion of the second dielectric layer, thereby electrically shorting the polysilicon layer to the drain of the HVFET. | 08-09-2012 |
20120188800 | ASYMMETRIC SWITCH FORWARD CONVERTER - A switching circuit for use in a power supply includes a first active switch coupled to a first terminal of a primary winding of a transformer. A second active switch is coupled to a second terminal of the primary winding of the transformer. An output capacitance of the first active switch is greater than an output capacitance of the second active switch. A first passive switch is coupled to the second active switch and to the second terminal of the primary winding. A second passive switch is coupled to the first active switch and to the first terminal of the primary winding. A reverse recovery time of the first passive switch is greater than a reverse recovery time of the second passive switch. A recovery circuit is coupled to receive a current from the first passive switch. | 07-26-2012 |
20120188799 | METHOD AND APPARATUS FOR INCREASING THE POWER CAPABILITY OF A POWER SUPPLY - One example controller for a power supply includes an oscillator, a drive signal generator, and a restart circuit. The oscillator generates a clock signal and the drive signal generator controls switching of a switch to regulate an output of the power supply in response to the clock signal. The restart circuit generates a restart signal in response to a current through the switch and in response to an absolute maximum on time period. The oscillator generates the clock signal to have a fixed maximum frequency in response to the restart signal indicating that the current through the switch reaches a current limit threshold within the absolute maximum on time period. The oscillator also generates the clock signal to have a variable minimum frequency in response to the restart signal indicating that the current through the switch has not reached the current limit threshold within the maximum on time period. | 07-26-2012 |
20120170329 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE IN A POWER CONVERTER - A control circuit includes a drive signal generator controlling switching of a power switch to regulate a flow of energy to one or more loads coupled to a power converter output. A regulator circuit charges a capacitor to a first voltage and stops charging the capacitor if an energy requirement of the one or more loads falls below a threshold. The regulator again charges the capacitor after the capacitor is discharged from the first voltage to a second voltage. An unregulated dormant mode control circuit renders dormant the drive signal generator and the regulator circuit while the capacitor is discharged from the first voltage to the second voltage causing the regulation of the flow of energy to the power converter output to cease. The drive signal generator and the regulator circuit are powered up after the capacitor is discharged from the first voltage to the second voltage. | 07-05-2012 |
20120170327 | APPARATUS AND METHOD FOR DETECTING A CHANGE IN OUTPUT VOLTAGE OF AN ISOLATED POWER CONVERTER - An output voltage sensor for use in a power converter controller includes a first pulse sampler circuit coupled to receive a feedback signal representative of an output of a power converter. The first pulse sampler circuit is coupled to capture a first peak voltage representative of a second peak of a ringing voltage of the feedback signal at a first time in the feedback signal. A second pulse sampler circuit is coupled to receive the feedback signal representative of the output of the power converter. The second pulse sampler circuit is coupled to capture a second peak voltage representative of the second peak of the ringing voltage of the feedback signal at a second time in the feedback signal. The output voltage sensor is coupled to output a change signal to a drive circuit of the power converter controller in response to the first and second peak voltages. | 07-05-2012 |
20120163043 | METHOD AND APPARATUS TO REGULATE AN OUTPUT VOLTAGE OF A POWER CONVERTER AT LIGHT/NO LOAD CONDITIONS - An example controller for a primary side control power converter includes a feedback circuit, a driver circuit, and an adjustable voltage reference circuit. The feedback circuit is coupled to compare a feedback signal representative of a bias winding voltage of the power converter with a voltage reference. The driver circuit is coupled to output a switching signal to control a switch of the power converter to regulate an output of the power converter in response the feedback circuit. The adjustable voltage reference circuit is coupled to adjust the voltage reference such that the bias winding voltage is adjusted nonlinearly in response to a load condition at the output of the power converter. The adjustable voltage reference circuit is further coupled to detect the load condition in response to the switching signal. | 06-28-2012 |
20120163041 | METHOD AND APPARATUS FOR A POWER SUPPLY CONTROLLER RESPONSIVE TO A FEEDFORWARD SIGNAL - An example power supply controller includes a switch duty cycle controller coupled to receive a feedback signal and a duty cycle adjust signal. The switch duty cycle controller is coupled to generate a drive signal coupled to control switching of a switch, which is coupled to an energy transfer element, to regulate energy delivered from an input of a power supply to an output of the power supply. The power supply controller also includes a gain selector circuit coupled to receive an input voltage signal, which is representative of an input voltage to the power supply, to generate the duty cycle adjust signal received by the switch duty cycle controller. The duty cycle of the drive signal to be varied in response to a plurality of linear functions over a range of values of the input voltage signal. | 06-28-2012 |
20120161815 | METHOD AND APPARATUS FOR TIME-DIFFERENTIAL COMPARISON OF AN ANALOG SIGNAL - A time-differential analog comparator is disclosed. An example apparatus according to aspects of the present invention includes a source of a variable frequency signal having a frequency responsive to an analog input. A counting circuit is coupled to count cycles of the variable frequency signal. The counting circuit is coupled to count in a first direction for a first time interval and is coupled to count in a second direction opposite to the first direction for a second time interval that occurs after an end of the first time interval. The counting circuit outputs a digital count signal and an evaluation circuit is coupled to generate a decision signal in response to the digital count signal after an end of the second time interval. The first time interval is not equal to the second time interval to generate an offset in the decision signal. | 06-28-2012 |
20120161739 | VARIABLE TIME CLAMP FOR A POWER SUPPLY CONTROLLER - An example integrated circuit for use in a power supply includes a feedback terminal and a controller having a variable time clamp (VTC). The feedback terminal is to be coupled to receive a feedback signal and the controller is to be coupled to enable or disable the conduction of a power switch during a switching cycle in response to the feedback signal. The controller includes a current limit comparator coupled to terminate the conduction of the power switch during an enabled switching cycle in response to a current through the power switch exceeding a variable current limit. The VTC is coupled to clamp the feedback terminal to a voltage for a clamp time that is responsive to the variable current limit. | 06-28-2012 |
20120155129 | METHOD AND APPARATUS TO LIMIT OUTPUT POWER IN A SWITCHING POWER SUPPLY - An example power supply includes an energy transfer element, a switch, and a controller. The controller includes a modulator, a drive signal generator, a comparator, and a variable current limit generator. The modulator generates an enable signal having logic states responsive to a feedback signal. The drive signal generator either enables or skips enabling a switch of the power supply during a switching period in response to the logic state of the enable signal. The comparator asserts an over current signal to disable the switch if the switch current exceeds a variable current limit. The variable current limit generator sets the variable current limit to a first current limit in response to one logic state of the enable signal and sets the variable current limit to a second current limit if the enable signal transitions logic states and the over current signal is asserted during the switching period. | 06-21-2012 |
20120151749 | METHOD AND APPARATUS FOR ADJUSTING DISPLACEMENT CURRENT IN AN ENERGY TRANSFER ELEMENT - Example methods include calculating a first number of turns of a shield winding included in an energy transfer element of a power supply. A first number of turns of the shield winding is calculated for the power supply to have a low noise current in an input conductor of the power supply. The method then includes increasing the first number of turns to a second number of turns. The power supply is then operated, which generates a first voltage waveform of a voltage between the input conductor and an output conductor of the power supply. An impedance is then inserted between the shield winding and the input conductor. The noise current is reduced by adjusting a value of the impedance until a second voltage waveform of the voltage between the input conductor and the output conductor reverses polarity to be the opposite of a polarity of the first voltage waveform. | 06-21-2012 |
20120147632 | APPARATUS AND METHOD FOR SENSING OF ISOLATED OUTPUT - A controller for use in a power converter includes a control circuit to be coupled to a current controller coupled to an energy transfer element. A first, second or third current is enabled in the current controller in response to the control circuit. The first current is substantially zero, the second current is greater than the third current, and the third current is greater than the first current. The third current only partially discharges a capacitance coupled to a terminal coupled between the energy transfer element and the current controller. A first feedback circuit coupled to the control circuit generates a first feedback signal after a full discharge pulse of current through the current controller. A second feedback circuit coupled to the control circuit generates a second feedback signal after a partial discharge pulse of current through the current controller. | 06-14-2012 |
20120146715 | Temperature Independent Reference Circuit - A temperature independent reference circuit includes first and second bipolar transistors with commonly coupled bases. First and second resistors are coupled in series between the emitter of the second bipolar transistor and ground. The first and second resistors have first and second resistance values, R | 06-14-2012 |
20120146607 | METHOD AND APPARATUS FOR INPUT CHARGE CONTROL OF A POWER SUPPLY - An example power supply includes an energy transfer element, a switch and a controller. The controller includes a logic circuit and a constant current control circuit. The logic circuit generates a drive signal to control the switch in response to a control signal. The constant current control circuit generates the control signal in response to a received input current sense signal, input voltage sense signal, and output voltage sense signal. An integrator included in the constant current control circuit integrates the input current sense signal to generate an integrated signal representative of a charge taken from the input voltage source. The constant current control circuit is adapted to generate the control signal to provide a constant current at the output of the power supply such that the integrated signal is proportional to a ratio of the output voltage sense signal to the input voltage sense signal. | 06-14-2012 |
20120146141 | ELECTRONIC CIRCUIT CONTROL ELEMENT WITH TAP ELEMENT - A technique for controlling a power supply with power supply control element with a tap element. An example power supply control element includes a power transistor that has first and second main terminals, a control terminal and a tap terminal. A control circuit is coupled to the control terminal. The tap terminal and the second main terminal of the power transistor are to control switching of the power transistor. The tap terminal is coupled to provide a signal to the control circuit substantially proportional to a voltage between the first and second main terminals when the voltage is less than a pinch off voltage. The tap terminal is coupled to provide a substantially constant voltage that is less than the voltage between the first and second main terminals to the control circuit when the voltage between the first and second main terminals is greater than the pinch-off voltage. | 06-14-2012 |
20120146105 | High-voltage transistor device with integrated resistor - A high-voltage device structure comprises a resistor coupled to a tap transistor that includes a JFET in a configuration wherein a voltage provided at a terminal of the JFET is substantially proportional to an external voltage when the external voltage is less than a pinch-off voltage of the JFET. The voltage provided at the terminal being substantially constant when the external voltage is greater than the pinch-off voltage. One end of the resistor is substantially at the external voltage when the external voltage is greater than the pinch-off voltage. When the external voltage is negative, the resistor limits current injected into the substrate. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. | 06-14-2012 |
20120140528 | FORWARD CONVERTER TRANSFORMER SATURATION PREVENTION - A power converter in one aspect limits the magnetic flux in a transformer. A control circuit included in the power converter includes a pulse width modulator, a logic circuit and a saturation prevention circuit. The saturation prevention circuit asserts a first signal when a first integral value of the input voltage reaches a first threshold value and asserts a second signal after a delay time that begins when a difference between the first integral value and a second integral value of a reset voltage of the transformer falls to a second threshold value. The logic circuit turns off the switch when the first signal is asserted, and allows the switch to turn on and off in accordance with the pulse width modulator when the second signal is asserted. | 06-07-2012 |
20120140525 | ENERGY TRANSFER ASSEMBLY WITH TUNED LEAKAGE INDUCTANCE AND COMMON MODE NOISE COMPENSATION - An energy transfer assembly with tuned leakage inductance and common mode noise compensation is disclosed. An example energy transfer assembly for use in a resonant power converter includes a first winding wound around a bobbin mounted on a magnetic core. The first winding has a first number of layers proximate to a first end along a length of the bobbin and a second number of layers proximate to a second end along the length of the bobbin. The energy transfer assembly also includes a second winding wound around the bobbin. The second winding has a third number of layers proximate to the first end along the length of the bobbin and a fourth number of layers proximate to the second end along the length of the bobbin. The first and second windings are wound around the bobbin such that at least a portion of one of the first and second windings overlaps at least a portion of an other one of the first and second windings around the bobbin. A degree of overlap between the first and second windings is non-uniform between the first and second ends along the length of the bobbin such that a ratio of the first number to the third number does not equal a ratio of the second number to the fourth number. | 06-07-2012 |
20120139342 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH OUTPUT RESET IN A POWER CONVERTER - An implementation of an unregulated dormant mode with an output reset controller in a power converter is disclosed. An example method for controlling an output of a power converter includes generating a drive signal with a drive signal generator to regulate a flow of energy to one or more loads coupled to an output of the power converter in response to an energy requirement of the one or more loads. The drive signal generator is rendered dormant to cease for a first time period the regulation of energy flow to the one or more loads when the energy requirement of the one or more loads falls below a threshold value. The energy requirement of the one or more loads is not responded to during the first time period. The drive signal generator is then powered up to resume after the first time period has elapsed the regulation of energy flow to the one or more loads. After the first time period has elapsed, it is identified whether there is an increase in the energy requirement of the one or more loads. If there is the increase in the energy requirement of the one or more loads, the output of the power converter is reset to allow a voltage at the output of power converter to be discharged during a second time period after the first time period has elapsed to a value substantially below a normal regulation output voltage. | 06-07-2012 |