Entries |
Document | Title | Date |
20080310192 | Output power limit for a switching mode power converter by a current limit signal having a multi-slope waveform - A current limit signal having a multi-slope waveform is provided for a power converter that has a power switch switched to convert an input voltage to an output voltage, for output power control more preciously. The current flowing through the power switch has a maximum value being a function of a duty cycle of the power switch when the power converter operates at a constant output power condition. The current limit signal is generated according to the function, and is compared with a sensing signal produced from the current flowing through the power switch, so as to turn off the power switch if the sensing signal is not lower than the current limit signal. | 12-18-2008 |
20090040796 | BIPOLAR TRANSISTOR DRIVERS - We describe a switching power converter comprising a bipolar switching device (BJT or IGBT) switching an inductive load, and including a closed-loop control system. The control system comprises a voltage sensing system to sense a voltage on a collector terminal of the switching device and provide a voltage sense signal; a controller; and a drive modulation system coupled to an output of the controller for modulating a drive to the control terminal of said bipolar switching device responsive to a controller control signal; wherein said controller is configured to monitor changes in the sensed voltage during a period when said switching device is switched on and to control said drive modulation system to control the degree of saturation of said bipolar switching device when the device is switched on and hence improve turn-off times. | 02-12-2009 |
20090086514 | Method and apparatus for providing power conversion using an interleaved flyback converter with automatic balancing - A method and apparatus for converting DC input power to DC output power. The apparatus comprises a plurality of parallel connected flyback circuits. A controller is coupled to the switches within the flyback circuits to provide accurate timing and automatic current balancing amongst the plurality of flyback circuits. | 04-02-2009 |
20090103335 | OVERCURRENT-PROTECTED SWITCHING-MODE POWER SUPPLY - A DC-to-DC converter having an active switch connected between a pair of DC input terminals via the primary winding of a transformer whose secondary winding is connected to a pair of DC output terminals via a rectifying and smoothing circuit. Operating under the control of an output voltage detector circuit, a switch control signal generator rapidly turns the active switch on and off so as to keep the DC output voltage constant. For overcurrent protection, a current detect resistor is connected in series with the active switch for providing an uncorrected current detect signal indicative of the current flowing through the active switch. An overcurrent protector generates, in response to a clocked ramp voltage, a correction voltage which builds up with time during each conducting period of the active switch. The correction voltage is subtracted from the uncorrected current detect signal to provide a corrected current detect signal. The switch control signal generator is caused to turn off the active switch when the corrected current detect signal rises to an overcurrent threshold. | 04-23-2009 |
20090316445 | High Voltage Power Supply - This invention pertains to the control of high voltage power, and in particular to control of high voltage power from low voltage sources while reducing unwanted self resonance in the windings of a self oscillating flyback converter. | 12-24-2009 |
20100054001 | AC/DC Converter with Power Factor Correction - A power converter is configured for usage in a power factor correction system. The power converter comprises a transformer with a primary winding and a secondary winding which isolates a primary side from a secondary side. A primary side switch is coupled to the primary winding. An isolator coupled to the primary side switch isolates the primary side from the secondary side and comprises a signal pathway passing a digital signal from the primary side to the secondary side. Power factor correction circuitry is coupled to the primary side switch and adjusts electric load characteristics to improve power factor toward unity. | 03-04-2010 |
20100165673 | Power supply having a two-way DC to DC converter - A power supply having a two-way DC to DC converter has an AC to DC converter and a two-way DC to DC converter. When an AC power is input to the AC to DC converter, the AC to DC converter transforms the AC power to a middle level DC power and the two-way DC to DC converter transforms the middle level DC power to a low level DC power. When the AC power is unavailable and the two-way DC to DC converter obtains an external DC power, the two-way DC to DC converter transforms the external DC power to the middle level DC power. Therefore, if the power supply obtains the external DC power, the power supply can still output the middle level DC power even the AC power is unavailable. | 07-01-2010 |
20100172159 | MULTIPLE-OUTPUT SWITCHING POWER SUPPLY UNIT - A multiple-output switching power supply unit includes: a voltage generating circuit Q | 07-08-2010 |
20100202166 | ENERGY SAVING LUMENS SETTABLE DEVICE FOR FLUORESCENT LAMPS - A circuit to supply an AC voltage to a fluorescent lamp load from an AC supply converts the supply to DC, boosts the voltage in a converter and then drives an inverter from the smoothed boosted voltage in such a manner that the inverter will not start if the load is too low and the inverter frequency is almost constant. The power factor of the circuit is maintaining very close to unity. | 08-12-2010 |
20100220504 | Power supply apparatus having multiple outputs - A power supply apparatus having multiple outputs is described. The power supply apparatus having multiple outputs which comprises a transformer, a first output circuit generating a first output voltage with respect to a power transferred to a secondary side of the transformer, and a first output controller generating a first control signal for controlling a power supply provided to a primary side of the transformer, includes: a second output circuit generating a second output voltage with respect to the power transferred to the secondary side of the transformer; and a second output controller controlling an output of the second output voltage, wherein the second output circuit includes a second switch performing a switching operation on current flows of the second output circuit, and the second output controller controls the switching operation of the second switch according to the first control signal and the second output voltage. Accordingly, a plurality of output circuits are provided in the secondary side of the transformer, and an output voltage of each output circuit is individually controlled. In addition, power losses are reduced and efficiency is increased, a simple configuration can be implemented, and stable control of the output voltages of the multiple outputs can be achieved. | 09-02-2010 |
20100302817 | DC-DC CONVERTER - A DC-DC converter includes a plurality of switch elements connected in series between both ends of a DC power source, a series circuit of a primary winding of a transformer and a capacitor, connected between a connection point of the plurality of switch elements and an end of the DC power source, a rectifying-smoothing circuit to rectify and smooth a voltage generated by a secondary winding of the transformer into a DC voltage, and a controller to change a switching frequency of the plurality of switch elements according to a feedback signal generated from the DC voltage and alternately turn on/off the plurality of switch elements. The controller includes a nonlinear response unit | 12-02-2010 |
20100321963 | SWITCHING POWER SUPPLY APPARATUS AND SEMICONDUCTOR DEVICE - A semiconductor device providing a control circuit for controlling a switching power supply apparatus includes: an intermittent-oscillation control circuit which outputs an enable signal providing instructions to execute and suspend switching alternately; a turn-on control circuit which changes between an execution state and a suspension state of the switching according to the enable signal, and outputs, only in the execution state, a turn-on signal which turns on the switching element with a switching period; and an intermittent-oscillation frequency control circuit which causes the turn-on control circuit to delay the changing between the execution state and the suspension state so that an intermittence period including periods during which the turn-on control circuit is in the execution state and the turn-on control circuit is in the suspension state falls outside of a specific time range. Intermittent oscillation is thus operated out of a specific frequency band within an audible frequency range. | 12-23-2010 |
20100328972 | VOLTAGE CONVERTER CIRCUIT AND METHOD FOR A CLOCK SUPPLY OF ENERGY TO AN ENERGY STORAGE - The present invention provides a voltage converter circuit for the clocked supply of energy to an energy storage based on an input voltage applied at an input applied at an input of the voltage converter circuit. The voltage converter circuit includes an energy storage and a switch arrangement, wherein the switch arrangement has a first switch and a second switch which are connected in parallel to each other and coupled to the energy storage. The first switch of the switch arrangement has a smaller turn-on voltage according to amount than the second switch, wherein a control terminal of the first switch is wired up such that the first switch is active in a startup phase of the voltage converter circuit to supply energy to the energy storage, and wherein a control terminal of the second switch is wired up such that the second switch is active after the startup phase to supply energy to the energy storage in a clocked way. Further, the voltage converter circuit has a feedback circuit which is implemented to provide a feedback signal depending on a change of the energy stored in the energy storage or depending on an amount of energy stored in the energy storage, wherein the feedback circuit has a switchable coupling element which is implemented to couple the feedback signal to the control terminal of the second switch, and wherein the switchable coupling element is implemented to provide a stronger coupling effect in a startup phase than after the startup phase. | 12-30-2010 |
20110019441 | METHOD AND APPARATUS FOR DIGITAL CONTROL OF A SWITCHING REGULATOR - In one aspect, a power supply regulator includes a feedback terminal, a node, a control circuit, a first current source, and a second current source. The node is coupled to the feedback terminal to provide a feedback state signal in response to a feedback current through the feedback terminal. The feedback state signal has feedback states that represent an output of the power supply. The control circuit is to be coupled to a power switch and to receive the feedback state signal to regulate the output of the power supply. The first current source is coupled to the node to provide a first current to the node. The second current source is coupled to the node to selectively remove a second current from the node to modulate the feedback current and to alter the feedback state of the feedback state signal. | 01-27-2011 |
20110038183 | SWITCHING REGULATOR HAVING TERMINAL FOR FEEDBACK SIGNAL INPUTTING AND PEAK SWITCHING CURRENT PROGRAMMING - A switching regulator of a power converter is provided and includes a feedback-input circuit, a programming circuit, and a peak-current-threshold circuit. The feedback-input circuit is coupled to a terminal of the switching regulator for receiving a feedback signal. The feedback-input circuit is operated in a first range of a terminal signal. The programming circuit is coupled to the terminal for generating a programming signal. The programming signal is operated in a second range of the feedback signal. The peak-current-threshold circuit generates a threshold signal in accordance with the programming signal. The feedback signal is coupled to regulate the output of the power converter, and the threshold signal is coupled to limit a peak switching current of the power converter. | 02-17-2011 |
20110038184 | Isolated AC-DC Converter with Master Controller on Secondary Side and Slave Controller on Primary Side - An isolated alternating current (AC)-direct current (DC) converter is disclosed. The isolated AC-DC converter comprises a slave control circuit including a slave driver module configured to receive a command and to control coupling of the slave control circuit to a primary-side inductor of a transformer based on the command, a master control circuit coupled to a secondary-side inductor of the transformer, the master control circuit including a master control module configured to sense a feedback voltage across a load and to generate the command based on the feedback voltage and a reference voltage, and a coupler configured to communicate the command from the master control module to the slave driver module and to provide isolation between the master control module and the slave driver module. | 02-17-2011 |
20110044076 | SYSTEMS AND METHODS FOR LOAD COMPENSATION WITH PRIMARY-SIDE SENSING AND REGULATION FOR FLYBACK POWER CONVERTERS - System and method for regulating an output voltage of a power conversion system. The system includes a sampling component located on a chip configured to receive an input voltage through a terminal. The sampling component is configured to sample the input voltage and generate a sampled voltage. Additionally, the system includes an error amplifier configured to process information associated with the sampled voltage and a threshold voltage and generate a first output signal, and a first signal generator configured to generate a second output signal and one or more third output signals. Moreover, the system includes a comparator configured to receive the first output signal and the second output signal and generate a comparison signal, and a gate driver directly or indirectly coupled to the comparator and configured to generate a drive signal based on at least information associated with the comparison signal. | 02-24-2011 |
20110096573 | CONTROL CIRCUITS AND METHODS FOR SWITCHING MODE POWER SUPPLIES - Circuits and method for sensing a system output voltage change and transmitting an electrical signal to an auxiliary winding on the primary side. In an embodiment, a primary side controller detects the electrical signal and turns a power switch on and off to transfer energy from a primary winding to a secondary winding. A secondary side controller generates a voltage pulse at a terminal of the secondary winding when the system output voltage is below a reference voltage. The secondary side controller includes an input terminal connected to a system output, an output terminal connected to a terminal of the secondary winding, and a ground terminal connected to a ground potential of the system output. | 04-28-2011 |
20110103104 | BIAS AND DISCHARGE SYSTEM FOR LOW POWER LOSS START UP AND INPUT CAPACITANCE DISCHARGE - A power supply including an AC input, a filter, a full wave rectifier, a converter, a second rectifier, and a bias system. The filter includes at least one differential capacitor coupled to the AC input. The full wave rectifier develops a DC bus voltage on a DC bus node. The converter includes a controller and operates to convert the DC bus voltage to a regulated output voltage. The second rectifier is coupled to the AC input for developing a DC bias voltage on a DC bias node. The bias system is coupled between the DC bias node and a reference node and provides at least one start-up voltage to the controller, such as a supply voltage or a sense voltage or the like. The bias circuit includes at least one current discharge path for discharging each differential capacitor within a predetermined time period when AC line voltage is removed. | 05-05-2011 |
20110110123 | SWITCHING MODE POWER SUPPLY SPECTRUM SHAPING AND THE METHOD THEREOF - Embodiments of circuits and methods for a switching mode power supply are described in detail herein. In one embodiment, a switching mode power supply includes a transformer having a primary winding and a secondary winding to supply power to a load, a feedback circuit that generates a feedback signal that varies in relation to the load on the secondary winding, a switching circuit coupled to the primary winding to control current flow through the primary winding, and a control circuit coupled to the switching circuit to control the on/off status of switching circuit in response to the feedback signal and the current flow through the primary winding. The control circuit comprises a spectrum shaping circuit configured to generate a spectrum shaping signal in response to the feedback signal. The spectrum shaping signal can then be used to regulate the switching frequency and the spectrum shaping range. | 05-12-2011 |
20110110124 | METHOD OF FORMING A SWITCHING REGULATOR AND STRUCTURE THEREFOR - In one embodiment, a power supply controller is configured to receive a sense signal (CS) having a negative value that is proportional to the input voltage. The power supply controller uses the sense signal to limit the switch ( | 05-12-2011 |
20110110125 | METHOD AND APPARATUS TO LIMIT MAXIMUM SWITCH CURRENT IN A SWITCHING POWER SUPPLY - An example integrated circuit for use in a power supply includes a switch, a terminal and a controller. The controller is coupled to control switching of the switch to regulate the output of the power supply in response to a feedback signal received at the terminal. The controller includes a comparator and an oscillator. The comparator is coupled to detect when a switch current through the switch exceeds a current limit and the oscillator is coupled to extend an off time of the switch in response to the comparator detecting that the switch current exceeds a current limit and if an on time of the switch is substantially equal to a sum of a leading edge blanking period and a current limit delay time period. The oscillator extends the off time of the switch independent of the feedback signal. | 05-12-2011 |
20110157925 | ENERGY-SAVING POWER CONVERTER HAVING SUSPEND MODE - The present invention relates to an energy-saving power converter having a suspend mode. The power converter includes an output port for being electrically connected to the electricity consuming device; a voltage-transforming unit for outputting an output voltage appropriate to the needs of the electricity consuming device; a sensor for assessing the electricity consuming mode of the electricity consuming device, and a switch for selectively determining whether the sensor is to be powered. A wake-up unit is further provided to generate a wake-up signal for activating the voltage-transforming unit to provide power normally. The invention therefore solves the problem of unnecessary energy consumption resulted from a constant voltage conversion during the course when the electricity consuming device need not be supplied with power. | 06-30-2011 |
20110194315 | 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. | 08-11-2011 |
20110194316 | SWITCHING POWER SUPPLY DEVICE - A switching power supply device including: a switching element which performs a switching operation; an output voltage generation circuit; a transformer reset detection circuit which generates a transformer reset signal; a secondary-side on-time signal generation circuit; a feedback control circuit which generates a feedback signal; a switching element drive circuit which controls the switching operation of the switching element according to the feedback signal; and an output voltage correcting signal generation circuit which generates an output voltage correcting signal from the feedback signal and a secondary-side on-time signal, and supplies the output voltage correcting signal to the feedback control circuit. | 08-11-2011 |
20110199795 | METHOD AND APPARATUS FOR A HIGH VOLTAGE POWER SUPPLY CIRCUIT - A power converter is disclosed. An example 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. A control circuit is coupled to receive a feedback signal representative of the power converter output during a feedback portion of an off time of the power switch. The control circuit is coupled to generate an output signal in response to the feedback signal. The output signal is coupled to be received by the power switch to control switching of the power switch to control a fraction of the feedback portion of the off time of the power switch that the feedback signal is above a threshold and another fraction of the feedback portion of the off time of the power switch that the feedback signal is below the threshold. | 08-18-2011 |
20110199796 | STRUCTURE OF A POWER SUPPLY - An improved structure of a power supply is based on an emitter-switched PWM controller and special structure transformer. An improved structure of a power supply mainly describes two primary side regulation (here called “PSR”) solutions based on above PWM controller that is used in charger/adapter solutions. These PSR solutions employ a transformer with special winding structure. It is required that adjacent reeling between its input bias winding and output winding, in which the input side of the transformer is connected to an AC input and an emitter-switched PWM controller, and the output side of the transformer is connected to a rectified diode. The present invention further provides low cost PSR solutions with higher system reliability, better line/load regulation, and short circuit characteristic. | 08-18-2011 |
20110211372 | COMPENSATION CIRCUITS AND CONTROL METHODS OF SWITCHED MODE POWER SUPPLY - A compensation circuit has a resistor, a switch and a compensation capacitor. The resistor and the switch are connected in series between a power node and a compensation node. The compensation capacitor is connected to the compensation node, whose voltage is responsive to the output power source. For a predetermined period of time after the voltage falls below a predetermined value, the switch is open and no current flows through the resistor from the power node to the compensation node. | 09-01-2011 |
20110211373 | 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 duty cycle of a pulse width modulated switching signal to provide a fixed peak switching current in the switch during light load conditions and a variable peak switching current during load conditions other than the light load condition. The multi-cycle modulator circuit enables the switch signal generator to provide a switch signal uninterrupted if the load condition is other than the light load condition 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 load condition is the light load condition. The multi-cycle modulator circuit adjusts the first time period in response to the feedback signal to regulate the output. | 09-01-2011 |
20110255313 | METHOD AND APPARATUS FOR REGULATING A DIODE CONDUCTION DUTY CYCLE - A power converter control method and apparatus is disclosed. An example control circuit includes a clock signal generator coupled to generate a clock signal to control switching of a power switch to be coupled to the control circuit. A feedback circuit is coupled to receive a feedback signal which is representative of an output of a power converter during a duration of a feedback portion of an off time of the power switch. The feedback circuit is coupled to respond to the feedback signal to control the clock signal generator to regulate a ratio of the duration of the feedback portion of the off time of the power switch divided by a duration of a total power switch switching cycle period. | 10-20-2011 |
20110267850 | Method and Apparatus of Operating a Primary-Side-Regulation Power Converter at Both Continuous Current Mode and Discontinuous Current Mode - A method and an apparatus of operating a primary-side-regulation power converter at both continuous current mode and discontinuous current mode are provided. The apparatus includes a switching circuit, a signal generator, a correlation circuit, and a feedback modulator. The signal generator generates a half signal and a second sampling pulse in response to a switching signal. The correlation circuit receives the half signal, the second sampling pulse and a switching-current signal for generating a modulating current. The feedback modulator modulates a feedback signal in response to the modulating current, a detection signal and the switching signal. The detection signal obtained from a transformer is correlated to an output voltage of the primary-side-regulation power converter. An on-period of the half signal is half of an on-period of the switching signal. The switching-current signal is sampled at a falling-edge of the half signal. | 11-03-2011 |
20110292693 | DIRECT-CURRENT POWER SUPPLY DEVICE - In a direct-current power supply device that includes a smoothing capacitor C | 12-01-2011 |
20120008347 | METHOD FOR OPERATING A DC/DC CONVERTER CIRCUIT CONFIGURATION AND DC/DC CONVERTER CIRCUIT CONFIGURATION - A DC/DC converter circuit configuration contains a rectifier configuration, an inductance and at least one circuit breaker for switching the inductance on its input side. When controlling the circuit configuration, an off time of the circuit breaker is variably changed on the basis of the output power of the circuit configuration and the circuit breaker is respectively switched on in the region of a minimum of a voltage curve across the circuit breaker in order to minimize the switching losses and achieve a high level of efficiency. | 01-12-2012 |
20120014142 | POWER CONVERSION APPARATUS FOR CORRECTING POWER FACTOR - A power conversion apparatus for correcting power factor, which converts an input voltage to an output voltage, comprises: an inductive component, a unidirectional conducting component, a switch, an energy storage component, a capacitive component, and an output circuit. The unidirectional conducting component connects to the inductive component and the switch in series. The energy storage component connects to the switch and the capacitive component in series. The capacitive component has a bias voltage. The output circuit couples to the energy storage component for outputting the output voltage. Wherein, the switch in a conduction state is capable of charging the inductive component by applying the input voltage and charging the energy storage component by applying the bias voltage, and the switch in a cutoff state is capable of discharging the capacitive component and the energy storage component to the output circuit and discharging the inductive component to the capacitive component. | 01-19-2012 |
20120044724 | SWITCHING POWER SUPPLY APPARATUS - A switching power supply apparatus that can precisely control the overload protection voltage is provided. The apparatus includes a secondary current on-period detection circuit for detecting the time between turn-off of the switching device and off-timing of the secondary current; and an output power limiting circuit for comparing the output signal of the secondary current on-period detection circuit with a signal indicating a predetermined maximum secondary current on-period, and for outputting an output power limiting signal for reducing or stopping power supply to a load to a switching signal control circuit when the former signal is higher than the latter signal, wherein the maximum secondary current on-period is arranged to correspond to the secondary current on-period when the device current flowing through the switching device reaches the maximum current defined by the switching signal control circuit, or the oscillation frequency of the device current reaches the maximum oscillation frequency defined by the oscillator, and the second DC voltage from the output voltage generation circuit is released from constant-voltage control and reduced. | 02-23-2012 |
20120057376 | POWER SUPPLY CIRCUIT - It is an object to obtain a detection circuit for detecting feedback voltage without variation in output voltage/current or in output voltage by the operation temperature, and a power supply circuit including thereof. A power supply circuit includes a detection circuit, an amplifier circuit outputting an output voltage, a control circuit, and a divider circuit. The detection circuit includes first and second reference voltage generation circuits and an input signal adjustment circuit. The control circuit is electrically connected to the amplifier circuit and includes the detection circuit, an error amplifier circuit, a pulse width modulation driver, a triangle-wave generation circuit, and a capacitor. The divider circuit is electrically connected to the amplifier circuit and the control circuit and inputs a voltage obtained by dividing the output voltage to the second reference voltage generation circuit. Note that the first and second reference voltage generation circuits are each a reference voltage circuit. | 03-08-2012 |
20120075890 | GATE DRIVER AND SWITCHING POWER SOURCE APPARATUS - A gate driver of a switching element includes a first capacitor having a first end connected to a DC power source, a first switch having a first electrode connected to the first end of the first capacitor and a second electrode connected to a negative electrode of the DC power source, a second switch having a third electrode connected to the second electrode and the negative electrode of the DC power source and a fourth electrode connected to the first capacitor, a second capacitor connected in parallel with the third and fourth electrodes of the second switch and having a first end connected to the DC power source, and a negative voltage controller connecting the gate of the switching element to the second end of the first capacitor and a second end of the second capacitor when the switching element is turned off. | 03-29-2012 |
20120081931 | METHOD AND APPARATUS TO CONTROL A POWER CONVERTER HAVING A LOW LOOP BANDWIDTH - An example controller includes a feedback sensor circuit that receives a feedback signal representative of an output of a power converter. A feedback sampling signal generator is coupled to generate a feedback sampling signal. The feedback sensor circuit samples the feedback signal in response to the feedback sampling signal. A state machine controls switching of a switch of a power converter circuit according to one of a plurality of operating condition states in response to the feedback sensor circuit. Each of the plurality of operating condition states includes a substantially fixed switch on time. A feedback time period signal generator generates a feedback time period signal received by the state machine. A period of the feedback time period signal is substantially greater than a period of the feedback sampling signal. The state machine is updated in response to the feedback time period signal. | 04-05-2012 |
20120113689 | SWITCHING POWER SUPPLY DEVICE - A switching power supply device that includes a feedback terminal to which a feedback signal according to a load state is input, and a comparator which compares a terminal voltage of the feedback terminal with a reference voltage and determines whether the load state is a normal load state or a light load state. The switching power supply device also includes pull-up resistors which are connected to the feedback terminal, a switch element which switches resistance values of the pull-up resistors according to the change of the load state, and a switch element which switches the resistance values of the pull-up resistors according to whether the input voltage is high or low. | 05-10-2012 |
20120113690 | METHOD AND APPARATUS FOR A HIGH VOLTAGE POWER SUPPLY CIRCUIT - A power switch is switched to regulate an output of a power converter. A feedback signal representative of a power converter output during a feedback portion of an off time of the power switch is received. The feedback signal is above a threshold during a fraction of the feedback portion of the off time of the power switch and the feedback signal is below the threshold during another fraction of the feedback portion of the off time of the power switch. The fractions of the feedback portion of the off time of the power switch are regulated in response to the feedback signal by controlling the switching the power switch. | 05-10-2012 |
20120134182 | CONTROL CIRCUITS AND METHODS FOR SWITCHING MODE POWER SUPPLIES - A switching mode power supply (SMPS) includes a transformer having a primary winding, a secondary winding for providing an output voltage, and an auxiliary winding. The SMPS also includes a power switch coupled to the primary winding. A first control circuit is coupled to the secondary winding, and is configured to provide a first electrical signal to the secondary winding when the output voltage of the SMPS is less than a reference voltage during a discontinuous time, whereupon a second electrical signal is induced in the auxiliary winding. A second control circuit is coupled to the auxiliary winding and the power switch. The second control circuit is configured to regulate the output of the SMPS by controlling the power switch in response to a feedback voltage signal from the auxiliary winding, and is further configured to turn on the power switch in response to the second electrical signal. | 05-31-2012 |
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 |
20120163042 | CIRCUIT AND METHOD OF FREQUENCY JITTER, AND APPLICATION THEREOF IN SWITCHED-MODE POWER SUPPLY (SMPS) - The present invention is to provide a frequency jitter circuit and a method for generating frequency jitter. The frequency jitter circuit, comprising: an oscillating circuit, configured to generate an oscillating frequency output signal; a decoding circuit, configured to be controlled by said oscillating frequency output signal for generating several pulse output signals; a delay circuit, through which said oscillating frequency output signal is passed for generating a frequency jitter output signal that is delayed a period of time compared to said oscillating frequency output signal. Application of the invention into switched-mode power supply might reduce EMI average noise in the switched-mode power supply, and smooth energy spectrum density. | 06-28-2012 |
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 |
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 |
20120250367 | CONTROL DEVICE OF THE SWITCHING FREQUENCY OF A QUASI-RESONANT SWITCHING CONVERTER AND RELATED CONTROL METHOD - A control device for a QR switching power converter is described; said power converter is adapted to convert an input signal to a DC output signal and comprises a power switch connected to said input signal and adapted to regulate said DC output signal and magnetic storage means. The control device is able to determine the switching frequency of the power switch and it is supplied by a feedback signal deriving from a feedback circuit coupled to the output signal of the power converter; said control device performs a control loop regulating the DC output signal by controlling a control variable. The control device comprises modulating means adapted to modulate said control variable as a function of at least one modulating signal having a frequency higher than the control loop bandwidth. | 10-04-2012 |
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 |
20120268971 | POWER SUPPLY FOR CONTROLLING CURRENT - The present invention relates to a power supply for controlling current that uses a flyback converter for electrical insulation between a load line unit and the power supply for controlling current. In a transformer (a flyback converter) having a flyback structure in the present invention, disclosed is a device which expects a current of the second coil by sensing a current of the first coil of the transformer, and controls the current flowing through the load line unit. A level detector is included, which updates a duty time or an on-time of the switch by transferring a reset signal to an integrator and a second sampler in accordance with a cycle of an input power. As a result, it is possible to reduce power loss by increasing a power factor through the adjustment of the phase of the current of the load line unit and an input voltage. | 10-25-2012 |
20120300508 | SYSTEMS AND METHODS FOR FLYBACK POWER CONVERTERS WITH SWITCHING FREQUENCY AND PEAK CURRENT ADJUSTMENTS - System and method for regulating a power converter. The system includes a comparator configured to receive a first signal and a second signal and generate a comparison signal based on at least information associated with the first signal and the second signal. The first signal is associated with at least an output current of a power converter. Additionally, the system includes a pulse-width-modulation generator configured to receive at least the comparison signal and generate a modulation signal based on at least information associated with the comparison signal, and a driver component configured to receive the modulation signal and output a drive signal to a switch to adjust a primary current flowing through a primary winding of the power converter. The modulation signal is associated with a modulation frequency corresponding to a modulation period. | 11-29-2012 |
20120314459 | FEEDBACK CIRCUIT AND POWER SUPPLY DEVICE INCLUDING THE SAME - Disclosed are a feedback circuit and a power supply device including the same. The power supply device converts input voltage into output voltage suitable for load condition according to a switching operation of a power switch. The feedback circuit includes a first diode connected to a first sensing voltage corresponding to output voltage and a second diode connected to the output voltage. The feedback circuit generates feedback voltage by using voltage passing through a conducted diode of the first and the second diodes. The power supply device controls a switching operation of the power switch depending on the feedback voltage. | 12-13-2012 |
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 |
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 |
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 |
20130044520 | SWITCH CONTROL CIRCUIT, POWER FACTOR CORRECTOR INCLUDING THE SAME, AND DRIVING METHOD OF THE POWER FACTOR CORRECTOR - The present invention relates to a switch control circuit, a power factor corrector including the same, and a driving method thereof. According to an exemplary embodiment of the present invention, a turn-on time of a power switch is controlled according to a zero crossing voltage to sense a voltage of both terminals of the power switch, and a turn-off time of the power switch is controlled according to a feedback voltage corresponding to the output voltage. At this time, the switching frequency of the power switch is sensed by the zero crossing voltage and the switching frequency is restricted by a predetermined threshold frequency. | 02-21-2013 |
20130044521 | SWITCHING POWER SUPPLY WITH OPTIMIZED THD AND CONTROL METHOD THEREOF - A switching power supply comprising a switching circuit and a controller. The controller comprises a preprocessing circuit, a first multiplier, a first comparing circuit and a logic circuit. The controller comprises a preprocessing circuit, a first multiplier, a first comparing circuit and a logic circuit. The preprocessing circuit generates a first multiplication input signal based on the input voltage and output voltage of the switching circuit. The first multiplier multiplies the first multiplication input signal by a second multiplication input signal and generates a first product signal. The first comparing circuit compares a current sensing signal representative of the input current with the first product signal and generates a first comparison signal. The logic circuit turns off a main switch in the switching circuit when the current sensing signal is larger than the first product signal. | 02-21-2013 |
20130063986 | CONTROL CIRCUIT FOR CONTROLLING THE MAXIMUM OUTPUT CURRENT OF POWER CONVERTER AND METHOD THEREOF - A control circuit of the power converter according to the present invention comprises a feedback circuit, an output circuit and an adaptive clamping circuit. The feedback circuit generates a feedback signal in accordance with an output of the power converter. The output circuit generates a switching signal in accordance with the feedback signal for regulating the output of the power converter. The adaptive clamping circuit limits the level of the feedback signal under a first level for a first load condition. The feedback circuit determines a slew rate of the feedback signal for increasing the level of the feedback signal from the first level to a second level. The adaptive clamping circuit is disabled and the level of the feedback signal can be increased to the second level for a second load condition. | 03-14-2013 |
20130063987 | CONTROL CIRCUIT OF SWITCHING POWER SUPPLY SYSTEM AND SWITCHING POWER SUPPLY SYSTEM - An input voltage detection unit detects whether an AC input voltage is the voltage of a 100V system or of a 200V system. In response, a frequency decreasing gain setting unit switches between frequency decreasing gain characteristics relative to load factors. The frequency decreasing gain characteristics are established so that the initiation of a decrease in a feed back signal in the 100V system is earlier than that in the 200V system. By switching the frequency decreasing gain characteristics based on an AC input signal, the characteristics, in which a decrease in a feed back signal in the 200V system is earlier than that in the 100V system, are cancelled to allow load factors, at each of which a power supply operation frequency reaches the audible region, to be approximately the same to enable a vibration isolating measure to be independent of the AC input voltage. | 03-14-2013 |
20130070487 | DRIVE CIRCUIT - A drive circuit drives a normally-on high-side switch Q | 03-21-2013 |
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 |
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 |
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 |
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 |
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 |
20130100715 | SYSTEMS AND METHODS FOR REDUCING ELECTOMAGNETIC INTERFERENCE USING SWITCHING FREQUENCY JITTERING - System and method are provided for regulating a power converter. The system includes a signal processing component configured to receive a first input signal and a second input signal, process information associated with the first input signal and the second input signal, and output a drive signal to a switch based on at least information associated with the first input signal and the second input signal. The first input signal is associated with at least a feedback signal related to an output voltage of the power converter. The second input signal is associated with at least a primary current flowing through a primary winding of the power converter. The signal processing component is further configured to change a peak value of the primary current within a first predetermined range, and change the switching frequency of the power converter within a second predetermined range. | 04-25-2013 |
20130121039 | SWITCHING AMPLIFIER WITH PULSED CURRENT SUPPLY - A switching amplifying method or a switching amplifier for obtaining one or more than one linearly amplified replicas of an input signal, is highly efficient, and does not have the disadvantage of “dead time” problem related to the class D amplifiers. Said switching amplifying method comprises the steps of: receiving the input signal; pulse modulating the input signal for generating a pulse modulated signal; switching a pulsed current from a direct current (DC) voltage according to the pulse modulated signal; conducting said pulsed current positively or negatively to a filter according to the polarity of the input signal; filtering said pulsed current positively or negatively conducted to the filter for outputting an output signal by the filter. | 05-16-2013 |
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 |
20130128627 | SWITCH CONTROL METHOD, SWITCH CONTROLLER, AND CONVERTER COMPRISING THE SWITCH CONTROLLER - The present invention relates to a converter, a switch controller controlling switching operation of a power switch in the converter, and a switch control method. An exemplary embodiment of the present invention generates a reference current corresponding to an output current of the converter and generates a control voltage that depends on the reference current. The exemplary embodiment controls an increase or a decrease of the control voltage and determines a switching frequency of the power switch according to the control voltage. The exemplary embodiment controls on-time of the power switch using a reference voltage determined according to a control current that depends on the reference current. | 05-23-2013 |
20130148388 | AC-DC flyback converter and loop compensation method thereof - The prevent invention provides an AC-DC flyback converter and a loop compensation method thereof. The AD-DC flyback converter comprises an isolating transformer, a power switch, and a feed control module. The feed control module includes a compensating circuit, a voltage buffer, and an error amplifier having a first resistor and a second resistor, and a pulse width modulation controller. With the AC-DC flyback converter and the loop compensating method, the system stability can be improved and the loop bandwidth can be reduced. | 06-13-2013 |
20130182464 | DC Converter With Low Starting Voltage - The present invention relates to an electronic circuit with which input voltages at an input of the circuit are converted into higher output voltages at an output of the circuit, whereby the voltage conversion already starts at low voltages at the input. According to the present invention, the DC converter circuit for the generation of an output voltage from an input voltage (V | 07-18-2013 |
20130188401 | CAPACITOR DISCHARGING CIRCUIT AND CONVERTER - A capacitor discharging circuit and a converter are disclosed. The converter comprises: a capacitor connected between the live line and null line of an AC power input terminals, a conversion module coupled to the capacitor and comprising an energy storage component at least, an energy transfer unit coupled with the energy storage component and the capacitor, an AC power-off detecting unit and a control unit; wherein the energy transfer unit comprises a switch device; when AC power is disconnected, the AC power-off signal triggers the control unit to output a switch driving signal, controlling the operation of the energy transfer unit to transfer the energy stored in the capacitor to the energy storage component to discharge the capacitor. | 07-25-2013 |
20130194837 | CONTROL CIRCUIT AND METHOD FOR A FLYBACK CONVERTER TO COMPENSATE FOR AN ENTRY POINT OF A BURST MODE - A control circuit and method are provided for a flyback converter converting an input voltage to an output voltage, to compensate for an entry point of a burst mode of the flyback converter, so that the entry point is not affected by the input voltage, and audible noise resulted from a higher input voltage is reduced without impacting the light load efficiency of the flyback converter. | 08-01-2013 |
20130201730 | Alternating Parallel Fly Back Converter with Alternated Master-Slave Branch Circuits - An alternating parallel flyback converter with alternated master and slave circuit branches is provided. The flyback converter includes a master flyback circuit branch, a slave flyback circuit branch connected with the master flyback circuit branch in parallel, and a controller. The controller controls the operation of each of the flyback circuit branches based on the current and the voltage at the output terminal of the flyback converter. The master flyback circuit branch operates continuously while the slave flyback circuit branch only operates when the output power of the flyback converter is higher than a threshold. The master flyback circuit branch and the slave flyback circuit branch are periodically alternated, and in particular, through zero crossing of the power. With the flyback converter of the present invention, the reliability and the service life of the converter can be improved. | 08-08-2013 |
20130201731 | POWER FACTOR CORRECTION DEVICE, AND CONTROLLER AND THD ATTENUATOR USED BY SAME - A power factor correction device, and a controller and a total harmonic distortion (THD) attenuator used by same. The power factor correction device comprises a converter and a controller ( | 08-08-2013 |
20130215649 | PRIMARY-SIDE REGULATED MODULATION CONTROLLER WITH IMPROVED TRANSIENT RESPONSE AND AUDILE NOISE - A switching mode power supply, and a primary-side controlled PFM converter using the primary-side regulated PFM controller are discussed. In present embodiment, the primary side cycle by cycle switch peak current is no longer a constant. The time detector is added to monitor the waveform of primary-side sample voltage and then generate the duty cycle. The transfer function should be selected to satisfy a specific relationship of switching frequency and switch peak current against with output loading current. The new design shows higher switching frequency but lower value of switch peak current at light load condition. This resolves the audible noise and poor transient response issue from the prior art PFM controller. | 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 |
20130223108 | CONSTANT VOLTAGE CONSTANT CURRENT CONTROLLER AND CONTROL METHOD THEREOF - The present invention relates to a constant voltage constant current (CVCC) controller, and associated control methods. In one embodiment, a CVCC controller for a flyback converter can include: (i) a current controller configured to generate an error signal by comparing an output current feedback signal against a reference current; (ii) a voltage controller configured to receive an output voltage feedback signal and a reference voltage, and to generate a control signal; (iii) a selector configured to control the flyback converter to operate in a first or a second operation mode based on the control signal, and to further generate a constant voltage or a constant current control signal based on the error signal; and (iv) a pulse-width modulation (PWM) controller configured to generate a PWM control signal to control a main switch, and to maintain the output voltage and/or current of the flyback converter as substantially constant. | 08-29-2013 |
20130235623 | TWO-SWITCH FLYBACK POWER CONVERTERS - A two-switch Flyback power converter is disclosed. The two-switch Flyback power converter comprises a transformer, a first switch, a second switch, and a control circuit. The transformer includes a primary-winding and a secondary-winding. The primary-winding has a first winding and a second winding. The first switch is coupled to switch the first winding. The second switch is coupled to switch the first winding and the second winding. The control circuit generates a first-drive signal and a second-drive signal to control the first switch and the second switch for switching the transformer and regulating an output of the two-switch Flyback power converter. The two-switch Flyback power converter with less capacitance of the bulk capacitor or bulk capacitor-less can reduce the voltage ripples at the output voltage for cost saving. | 09-12-2013 |
20130250629 | CONSTANT VOLTAGE CONSTANT CURRENT CONTROL CIRCUITS AND METHODS WITH IMPROVED LOAD REGULATION - The present invention discloses CVCC circuits and methods with improved load regulation for an SMPS. In one embodiment, the CVCC can include: a voltage feedback circuit to generate an output voltage feedback signal; a current feedback circuit to generate an output current feedback signal; a control signal generating circuit that receives the output voltage feedback signal and the output current feedback signal, and generates a constant voltage/constant current control signal; a first enable signal generating circuit that compares a first reference voltage and the constant voltage/constant current control signal to generate a first enable signal; and a PWM controller that generates a PWM control signal based on the constant voltage/constant current control signal to control a main switch of the flyback SMPS. | 09-26-2013 |
20130258723 | SYSTEMS AND METHODS FOR CONSTANT VOLTAGE CONTROL AND CONSTANT CURRENT CONTROL - System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal, a second controller terminal and a third controller terminal. The system controller is configured to receive an input signal at the first controller terminal and turn on or off a switch based on at least information associated with the input signal to adjust a primary current flowing through a primary winding of the power conversion system, receive a first signal at the second controller terminal from the switch, and charge a capacitor through the third controller terminal in response to the first signal. | 10-03-2013 |
20130272036 | SYSTEMS AND METHODS FOR REGULATING POWER CONVERSION SYSTEMS WITH OUTPUT DETECTION AND SYNCHRONIZED RECTIFYING MECHANISMS - System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal and a second controller terminal. The system controller is configured to receive at least an input signal at the first controller terminal, and generate a gate drive signal at the second controller terminal based on at least information associated with the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power conversion system. The system controller is further configured to, if the input signal is larger than a first threshold, generate the gate drive signal at a first logic level to turn off the transistor. | 10-17-2013 |
20130272037 | POWER SUPPLY CIRCUIT FOR REMOTELY TURNING-ON ELECTRICAL APPLIANCES - A power supply circuit for an electrical appliance, including a turning-on stage configured for determining a transition from a turned-off state, in which the power supply circuit is off and does not supply electric power, to a turned-on state of the power supply circuit. The turning-on stage includes a transducer of the remote-control type configured for triggering the transition in response to the reception of a wireless signal. In some embodiments, operating power is transmitted from a remote controller to a control circuit of the electronic equipment, such that the electronic equipment can be turned on remotely but draws zero standby power. | 10-17-2013 |
20130329470 | CONTROL DEVICE FOR A DC-DC CONVERTER - A control device controls a switching circuit of a DC-DC converter. The switching circuit includes a half-bridge with at least first and second switches connected between an input voltage and a reference voltage. The converter comprises a transformer with a primary coupled with the center point of the half-bridge and a secondary coupled with a load. The control device comprises an error detector configured to determine an error signal representing a difference between a first signal representative of the voltage across the load and a first reference signal and a frequency controller configured to increase the switching frequency of the half-bridge when the error signal is kept below a second signal. | 12-12-2013 |
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 |
20140016376 | CONFIGURABLE POWER CONTROLLER WITH COMBINATION INPUT - Embodiments described herein describe a power supply configured to provide power to an output load via a power supply transformer. The power supply includes a controller configured to operate in a configuration state and an operating state. During the configuration state, the controller receives a configuration signal from a sense circuit coupled to the controller and selects one of a plurality of operating modes from the configuration signal. During the operating state, the controller controls a switch coupled to the transformer based on the selected operating mode and a sense signal received from the sense circuit representative of the power provided to the output load by the power supply. When the switch is closed, current flows from a power source through the transformer, and when the switch is open, current is prevented from flowing from the power source through the transformer. | 01-16-2014 |
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 |
20140036552 | SEMICONDUCTOR DEVICE PROVIDED WITH SWITCHING POWER SUPPLY DEVICE WITH INTERMITTENT OSCILLATION CONTROL - A control circuit varies an intermittent oscillation frequency using a period signal. A period signal period signal frequency is set to a frequency lower than the intermittent oscillation frequency, or is set to be higher than the intermittent oscillation frequency and to a frequency other than integer multiples of the intermittent oscillation frequency. The phase difference of the period signal with respect to an intermittent oscillation control signal is set so that the distribution of the intermittent oscillation frequency is dispersed. | 02-06-2014 |
20140056037 | CONTROL CIRCUIT AND INTERLEAVED POWER SUPPLY INCLUDING THAT CONTROL CIRCUIT - A control circuit that controls an interleaved power supply, and an interleaved power supply including that control circuit, which are unlikely to be affected by a variation among components and are suitable for mass production, are provided. The clock generator generates a clock pulse having a predetermined frequency. The signal doubler generates a master switch on-interval pulse signal indicating information concerning an on-interval of the master switch based on the clock pulse and a master drive pulse signal that switch-drives the master switch of the master converter, and generates a doubled duty pulse signal having a duty that is double that of the master switch on-interval pulse signal. The edge pulse generator generates a first edge pulse signal based on the master drive pulse signal, and generates a second edge pulse signal based on the doubled duty pulse signal. The slave drive pulse signal generator generates, based on the first edge pulse signal and the second edge pulse signal, a slave drive pulse signal that switch-drives the slave switch so that an on-interval of the slave switch is identical to an on-interval of the master switch. | 02-27-2014 |
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 |
20140071717 | SWITCHING POWER SUPPLY APPARATUS AND SEMICONDUCTOR DEVICE - A switching power supply apparatus includes: an input terminal; an output terminal; a switching element; an input and output converting unit which converts input voltage applied through the switching element into output voltage to supply output power to a load; an output voltage feedback unit which outputs a feedback signal, based on the output voltage; a switch current detecting unit which detects current flowing through the switching element; an oscillating frequency setting unit which sets the switching frequency of the switching element, based on the feedback signal; a peak current setting unit which controls turn-off of the switching element by setting a current threshold such that a switch current peak (i) is constant regardless of a change in the output power and (ii) increases as the input voltage increases; and a switching control unit which controls switching operation of the switching element. | 03-13-2014 |
20140085943 | Controller with Quasi-Resonant Mode and Continuous Conduction Mode and Operating Method Thereof - The present invention relates to a controller with quasi-resonant mode and continuous conduction mode and an operating method thereof. The controller comprises: a transformer, a switching unit, a load-detecting unit and a controlling unit, and the transformer has a first winding and a secondary winding. The secondary winding connects to a load in parallel, and the switching unit electrically couples to the first winding. The load-detecting unit electrically couples to the switching unit for detecting status of the load. The controlling unit electrically couples between the switching unit and the load-detecting unit for switching operating modes between a quasi-resonant mode and a continuous conduction mode based on the status of the load. | 03-27-2014 |
20140092647 | FLYBACK CONVERTER AND METHOD FOR CONTROLLING A FLYBACK CONVERTER - A flyback converter includes a transformer and a controller operable for controlling a switch coupled in series with a primary winding of the transformer. The controller is configured to operate in multiple modes including a burst mode and a standby mode. In the burst mode, the controller generates a first plurality of discrete pulse groups to turn on the switch and a duration of each pulse in the first plurality of discrete pulse groups is determined by a first reference signal having a first predetermined voltage. In the standby mode, the controller generates a second plurality of discrete pulse groups to turn on the switch and a duration of each pulse in the second plurality of discrete pulse groups is determined by a second reference signal having a second predetermined voltage which is greater than the first predetermined voltage of the first reference signal. | 04-03-2014 |
20140092648 | SWITCH-MODE POWER SUPPLY CONTROL APPARATUS AND FLYBACK SWITCH-MODE POWER SUPPLY INCLUDING THE CONTROL APPARATUS - The present invention discloses a switch-mode power supply control apparatus comprising a PWM controller for outputting a driving signal and a short-circuit protection module coupled to a detection terminal. The detection terminal receives a zero-crossing detection voltage. If the time that the detection voltage input to the detection terminal is lower than a first reference voltage exceeds a predetermined time period, the short-circuit protection module determines that a short-circuit abnormal situation occurs, the short-circuit protection module outputs a short-circuit signal to the PWM controller, and the driving signal output by the PWM controller becomes a turn-off signal. If the short-circuit protection module does not detect the short-circuit abnormal situation, the PWM controller operates normally. The present invention further discloses a flyback switch-mode power supply comprising the switch-mode power supply control apparatus. The flyback switch-mode power supply has a low power consumption when a short-circuit protection is taking place. Also, the transformer will not be saturated, which may otherwise lead to the damage of the power transistor. Further, the present invention makes it easier to test the short-circuit performance. | 04-03-2014 |
20140098579 | SWITCHED-MODE POWER SUPPLY - Consistent with example embodiments disclosed, there are switched-mode power supplies (SMPS) in which a signaling capacitor transmits information across a transformer of the power supply. Such embodiments can avoid drawing power from the output capacitor in order to provide communication signals and so do not cause a drop in the output voltage when signaling to the primary side. Further, the switched mode power supply can send signals from the secondary side of the transformer to the primary side via the transformer itself and so may not require the incorporation of an opto-coupler. Such embodiments may reduce production costs, the printed circuit board (PCB) footprint and reduce the no-load power consumption of the SMPS. | 04-10-2014 |
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 |
20140126250 | CONTROL CIRCUIT OF POWER CONVERTER WITH TEMPERATURE CONTROL AND METHOD FOR CONTROLLING POWER CONVERTER - A control circuit of a power converter and a method for controlling the power converter are provided. The control circuit of the power converter comprises a switching circuit and a temperature-sensing device. The switching circuit generates a switching signal in response to a feedback signal, and the switching circuit generates a current-sensing signal for regulating an output of the power converter. The temperature-sensing device generates a temperature signal in response to temperature of the temperature-sensing device. | 05-08-2014 |
20140140109 | FLYBACK POWER SUPPLY REGULATION APPARATUS AND METHODS - Apparatus and methods disclosed herein are associated with a primary side voltage and/or current regulator (PSR) in a flyback power converter. Apparatus and methods sense characteristics of a waveform generated in an auxiliary primary winding of a flyback transformer at a single terminal of the PSR. The waveform is analyzed, and error signals derived therefrom are used to maintain constant voltage and/or constant current regulation and to generate a peak current stabilization signal that is independent of line input voltage. | 05-22-2014 |
20140146580 | CABLE COMPENSATION CIRCUIT AND POWER SUPPLY INCLUDING THE SAME - A cable compensation circuit compensates a voltage drop in a cable coupled between a power supply and a load. The cable compensation circuit includes: a node where a voltage that depends on an input voltage of the power supply during a turn-on period of a power switch of the power supply and depends on an output voltage of the power supply during a turn-off period of the power switch is generated; a sensing RC filter generating a sense voltage that depends on a diode current by filtering the voltage of the node; and an averaging RC filter generating an average voltage by averaging the sense voltage. | 05-29-2014 |
20140160810 | Digital Communication Link Between Secondary Side and Primary Side of Switching Power Converter - A switching power converter provides a communication link between a secondary side and a primary side of the switching power converter. During a messaging mode, the communication link enables information to be transmitted from an electronic device coupled to the secondary side to a controller on the primary side. The communication link may be used to transmit operating parameters related to powering the electronic device. The switching power converter may then adapt its switching operation to achieve different regulated output voltage and/or current to accommodate the detected electronic device. | 06-12-2014 |
20140185337 | TRANSVERSE SHIELD WIRE FOR ENERGY TRANSFER ELEMENT - Energy transfer elements having a shield to reduce EMI while maintaining a low profile are disclosed. In one example, the transformer may include a transverse shield wire that may be utilized to keep displacement current within the energy transfer element. While windings of the energy transfer element are generally wound axially around the axis of a bobbin in a direction generally perpendicular to the axis of the bobbin, the transverse shield wire may be placed on the bobbin extending over multiple power windings of the energy transfer element in a transverse direction. The transverse shield wire may be situated outside all other windings wound around the bobbin. In some examples, one end of the transverse shield wire may be coupled to a switching node of the energy transfer element while the other end of the transverse shield wire may be coupled to a winding of the energy transfer element. | 07-03-2014 |
20140204627 | SYSTEMS AND METHODS FOR DRIVING A BIPOLAR JUNCTION TRANSISTOR BY ADJUSTING BASE CURRENT WITH TIME - System and method for driving a bipolar junction transistor for a power converter. The system includes a current generator configured to output a drive current signal to a bipolar junction transistor to adjust a primary current flowing through a primary winding of a power converter. The current generator is further configured to output the drive current signal to turn on the bipolar junction transistor during a first time period, a second time period, and a third time period, the second time period separating the first time period from the third time period, drive the bipolar junction transistor to operate in a hard-saturation region during the first time period and the second time period, and drive the bipolar junction transistor to operate in a quasi-saturation region during the third time period. | 07-24-2014 |
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 |
20140211519 | SINGLE-STAGE PFC CONVERTER WITH CONSTANT VOLTAGE AND CONSTANT CURRENT - An exemplary embodiment of a switching controller for a power converter is provided. The switching controller for a power converter comprises: a power device, an input circuit and a compensation capacitor. The power device is coupled to switch a transformer of the power converter for regulating an output voltage and an output current of the power converter. The input circuit is coupled to the transformer to sample an input signal which is correlated to the output voltage of the power converter to obtain a feedback signal. The feedback signal is utilized to generate a switching signal for controlling the power device. The switching signal is modulated to operate the power converter in boundary current mode (BCM) or discontinuous current mode (DCM). | 07-31-2014 |
20140233275 | ADAPTIVE ACTIVE CLAMP OF FLYBACK POWER CONVERTER WITH HIGH EFFICIENCY FOR HEAVY LOAD AND LIGHT LOAD - A control circuit of a flyback power converter according to the present invention comprises a low-side transistor, an active-damper, a high-side drive circuit, and a controller. The low-side transistor is coupled to switch a transformer. The active-damper is coupled in parallel with the transformer. The high-side drive circuit is coupled to drive the active-clamper. The controller generates a switching signal and an active-clamp signal. The switching signal is coupled to drive the low-side transistor. The switching signal is generated in accordance with a feedback signal for regulating an output of the flyback power converter. The active-clamp signal is coupled to control the high-side drive circuit and the active-damper. The active-clamp signal is generated in response to a demagnetizing time of the transformer. The pulse number of the active-clamp signal is less than the pulse number of the switching signal in a light load condition. | 08-21-2014 |
20140241014 | SYSTEMS AND METHODS FOR REAL-TIME SIGNAL SAMPLING IN POWER CONVERSION SYSTEMS - System and method for regulating a power conversion system. An example system controller includes a signal processing component and a driving component. The signal processing component is configured to receive a feedback signal associated with an output signal of a power conversion system and generate a processed signal based on at least information associated with the feedback signal. The driving component is configured to generate a drive signal based on at least information associated with the processed signal and output the drive signal to a switch in order to affect a primary current flowing through a primary winding, the drive signal being associated with a demagnetization period corresponding to a demagnetization process of the power conversion system. The signal processing component is further configured to, sample and hold the feedback signal a plurality of times during the demagnetization period to generate a plurality of sampled and held signals. | 08-28-2014 |
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 |
20140268923 | MAGNETIC SENSING TECHNIQUE FOR POWER SUPPLY SYSTEMS - One embodiment includes a power supply system including a transformer comprising a primary, secondary, and auxiliary winding that are magnetically coupled. The system also includes a switch stage that generates a current through the primary winding in response to activation of a switch based on a control signal that is generated based on a feedback voltage associated with the auxiliary winding. The current can be induced in the secondary winding. The system also includes an output stage coupled to the secondary winding and that generates an output voltage based on the current induced in the secondary winding. The system further includes a feedback stage coupled to the auxiliary winding and comprising a discriminator configured to determine a zero-current condition associated with the current induced in the auxiliary winding based on monitoring a change in slope of the feedback voltage and to measure the feedback voltage during the zero-current condition. | 09-18-2014 |
20140268924 | CONTROL CIRCUIT FOR FLYBACK POWER CONVERTER AND CALIBRATION METHOD THEREOF - A control circuit of a flyback power converter includes a first reference signal generating circuit for generating a first reference signal; a reference signal adjusting circuit for generating an adjustment signal according to the first reference signal and a test signal corresponding to an output voltage signal of the flyback power converter, and to generate a second reference signal according to the adjustment signal and the first reference signal; an error detection circuit for generating an error signal according to the second reference signal and a feedback signal; and a control signal generating circuit for generating a control signal according to the error signal to control operations of a power switch to thereby adjust the test signal. The feedback signal corresponds to a current flowing through a primary side coil of the power converter or a sensing voltage of an inductive coil of the power converter. | 09-18-2014 |
20140286058 | UNDERVOLTAGE PROTECTION CIRCUIT, UNDERVOLTAGE PROTECTION METHOD AND SWITCHING POWER SUPPLY - In one embodiment, an undervoltage protection circuit for a switching power supply can include: (i) an undervoltage detection circuit that determines whether an input voltage of the switching power supply is in an undervoltage state; (ii) a selection circuit configured to select a first or a second control signal to be provided as a main control signal to a control circuit; (iii) the control circuit being configured, in response to the main control signal being the first control signal, to control a switching operation of a power transistor in the switching power supply such that an output voltage of the switching power supply is maintained as substantially stable; and (iv) the control circuit being configured, in response to the main control signal being the second control signal, to control the switching operation of the power transistor to reduce an input power of the switching power supply. | 09-25-2014 |
20140293660 | Switched Mode Power Supply - A switching power converter includes an inductor coupled to a terminal operably supplied with an input voltage. A semiconductor switch is coupled to the inductor and configured to enable and disable an input current passing through the inductor in accordance with a drive signal. A current sense circuit is coupled to the inductor or the semiconductor switch and is configured to generate a current sense signal representing the input current passing through the inductor or the semiconductor switch. A control circuit receives the current sense signal and is configured to: close the semiconductor switch regularly in accordance with a clock frequency, to integrate the current sense signal thus providing an integrated current sense signal to compare the integrated current sense signal with a threshold that is a function of the input voltage. | 10-02-2014 |
20140328090 | SWITCHING POWER SUPPLY APPARATUS AND SEMICONDUCTOR DEVICE - A switching power supply apparatus includes a PFM control circuit that outputs a clock signal Set such that a switching frequency of a switching element varies in accordance with a load state. The clock signal Set determines a turn-on timing of the switching element. A reference value of a current flowing through the switching element determines a turn-off timing of the switching element. A modulation signal is applied to the turn-off timing of the switching element to modulate one of a peak value of a drain current flowing through the switching element and an on-time of the switching element. Input control is performed separately on the clock signal Set and the modulation signal. Accordingly, even when the clock signal Set and the modulation signal contribute to each other to offset each other, modulation effects are not cancelled. | 11-06-2014 |
20140340944 | METHOD PROVIDING SHORT-CIRCUIT PROTECTION AND FLYBACK CONVERTER UTILIZING THE SAME - A method providing short-circuit protection and a flyback converter utilizing the same wire are disclosed. The a method, adopted by a flyback converter, includes a transformer, including generating a feedback voltage according to an output voltage output from a secondary winding of the transformer; controlling a primary current through a primary winding of the transformer based on the feedback voltage; determining a sense voltage according to the primary current; determining a short circuit based on the sense voltage; setting the primary current according to a short-circuit sense voltage limit when a short circuit occurs; and setting the primary current according to a normal sense voltage limit when a short circuit does not occur. | 11-20-2014 |
20140340945 | POWER CONTROLLER WITH PULSE SKIPPING - A controller for a power converter includes a drive circuit coupled to generate a drive signal in response to an error signal representative of a load of the power converter. The drive circuit includes a pulse skipping circuit coupled to generate a blanking signal in response to the error signal. The pulse skipping circuit includes an enable circuit and a blanking circuit. The enable circuit is coupled to output an enable signal in response to the error signal. The blanking circuit is coupled to output the blanking signal in response to the enable signal and a ramp signal. The ramp signal is generated in response to the error signal. A duration of the blanking signal corresponds to a length of time for the ramp signal to reach a reference signal. The length of time is responsive to the error signal. | 11-20-2014 |
20140340946 | POWER SWITCH DRIVING CIRCUITS AND POWER CONVERTERS THEREOF - In one embodiment, a power switch driving circuit can include: (i) an upper switch having a first power terminal coupled to a voltage source, and a second power terminal coupled to a driving signal; (ii) a lower switch having a first power terminal coupled to the driving signal, and a second power terminal coupled to a first voltage level, where the first voltage level is higher than a first ground potential; (iii) an upper switch driving sub circuit configured to receive a control signal, and to drive the upper switch in response thereto; and (iii) a lower switch driving sub circuit configured to receive the control signal, and to drive the lower switch in response thereto, where the upper and lower switch driving sub circuits are coupled to a second ground potential. | 11-20-2014 |
20140362614 | SWITCHING POWER SUPPLY DEVICE, SWITCHING POWER SUPPLY CONTROL METHOD AND ELECTRONIC APPARATUS - Provided is a switching power supply device in a critical mode, including a load detection section that detects a load. When the detected load is lighter than a setting value, an upper limit of a switching frequency is lowered stepwise. | 12-11-2014 |
20140362615 | POWER SUPPLY APPARATUS AND PRINTING APPARATUS - The power supply includes a transformer for generating a first output voltage by a first secondary winding, and a superimposing voltage by a second secondary winding, and a driver. Furthermore, the circuit includes first and second rectifying and smoothing circuits for respectively rectifying and smoothing the first output voltage and superimposing voltage, and an adder for adding the rectified and smoothed superimposing voltage on the rectified and smoothed first output voltage to output a second output voltage. The first and second output voltages are fed back respectively by DC coupling, the fed-back first and second output voltages are respectively adjusted by first and second feedback factors, and the adjusted feedback components are combined and amplified to be applied to the driver for PWM-control. | 12-11-2014 |
20150009721 | VOLTAGE CONVERTER CONTROLLER AND VOLTAGE CONVERTER CIRCUIT - A voltage converter controller and a voltage converter circuit, either of which includes a voltage-drop compensating circuit for compensating a voltage drop between an output voltage and a load. The voltage-drop compensating circuit includes a trans-conductance stage and a squarer. The trans-conductance stage outputs a compensating sink current to a voltage dividing terminal of the output voltage and outputs a compensating source current to a reference voltage terminal of an error amplifier. An input terminal of the squarer is coupled to an output terminal of the error amplifier. An output terminal of the squarer is coupled to an input terminal of the trans-conductance stage. | 01-08-2015 |
20150009722 | POWER SUPPLY - Provided is regulation of a line current. The regulation of the line current includes comparing a reference voltage with a line sensing voltage to generate a feedback voltage, and controlling a switching operation of a power switch using the feedback voltage. The reference voltage may be a voltage having a constant level, a voltage which varies according to an output current, or a voltage which follows a sine wave to compensate a power factor. Provided is sensing of an output current. The sensing of the output current includes sensing the output current using a feedback voltage corresponding to a voltage between both terminals of an inductor connected to a power switch, a peak of current flowing through the power switch, and a switching cycle of the power switch. | 01-08-2015 |
20150023070 | AC/DC CONVERTER - A first rectified voltage obtained by rectifying an AC voltage is input to an input detection terminal of a control circuit. A first NMOS transistor configured as a depletion-type high-voltage element, and its drain is connected to the input detection terminal, and its gate is connected to its source. An AC voltage detection circuit detects the amplitude of the AC voltage based on a current that flows through the first NMOS transistor. | 01-22-2015 |
20150029762 | VOLTAGE CONVERTER COMPENSATION APPARATUS AND METHODS - On the secondary side of a flyback switching power converter, a compensation diode and a voltage divider with an averaging circuit generate an output current-compensated reference voltage that is proportional to converter output current. The current-compensated reference voltage is added to a regulation feedback controller reference voltage, which in turn adjusts the negative feedback signal to the PWM regulation controller on the primary side in proportion to the converter output current draw. The net effect is to increase the converter output voltage set-point in proportion to the converter output current draw as compensation for a voltage drop in a cable connecting the converter to a powered device. More precisely-regulated voltage levels may be delivered to an input of the powered device as a result. | 01-29-2015 |
20150055379 | SWITCHED-MODE POWER SUPPLY FOR PROVIDING A STABLE OUTPUT VOLTAGE - The present invention is a switched-mode power supply for providing a stable output voltage. An excitation winding, a vice-output winding and an active snubber circuit are connected to a primary side of a flyback-based transformer. A main-output winding is connected to a secondary side of the transformer. A primary-side PWM controller and a secondary-side PWM controller are respectively connected to the primary side and the secondary side of the transformer. By a time-shared-energy-transfer method, the main-output winding and the vice-output winding are controlled to sequentially extract demand electricity from the transformer during a same switching cycle. Additionally, by a time-shared-energy transformation, the output voltage on the secondary side of the transformer is stabilized to be provided between a stable minimal voltage and a preset higher voltage for satisfying a heavy-loading status and a light-loading status. | 02-26-2015 |
20150055380 | POWER DELIVERY DEVICE, AC ADAPTER AND ELECTRONIC APPARATUS - A power delivery (PD) device includes: an AC/DC converter connected to an AC input, the AC/DC converter configured to change the AC input to a desired voltage value to be output in accordance with a first voltage changing control signal supplied from outside; and a DC/DC converter connected between an output of the AC/DC converter and a DC output, the DC/DC converter configured to change the output from the AC/DC converter to a desired voltage value to be output as a DC output in accordance with a second voltage changing control signal supplied from outside, wherein the AC/DC converter at a previous stage and the DC/DC converter at a subsequent stage are interlocked to change the output voltage to desired target voltage. There can be provided the PD device capable of delivering power with high power efficiency over the wide voltage ranges. | 02-26-2015 |
20150062981 | SYSTEMS AND METHODS FOR ADJUSTING FREQUENCIES AND CURRENTS BASED ON LOAD CONDITIONS OF POWER CONVERSION SYSTEMS - Systems and methods are provided for regulating a power conversion system. An example system controller includes a driving component and a detection component. The driving component is configured to output a driving signal to a switch associated with a first current flowing through a primary winding of a power conversion system, the switch including a first switch terminal related to a first voltage and a second switch terminal related to a second voltage, the driving signal being associated with a plurality of switching periods. The detection component is configured to receive an input signal associated with a difference between the first voltage and the second voltage, detect at least one valley of the input signal in magnitude during a detection period for the first switching period, and output a detection signal based on at least information associated with the input signal to affect the driving signal. | 03-05-2015 |
20150070946 | METHOD AND APPARATUS FOR POWER DRIVING - Aspects of the disclosure provide a power circuit to provide electric energy with control and protection for driving a load, such as a light emitting diode (LED) array, and the like. The power circuit includes a converter, a voltage feedback module, a current feedback module and a controller. The converter is configured to receive electric energy from an energy source and to deliver the electric energy for driving the load. The voltage feedback module is configured to generate a first feedback signal based on a voltage of the delivered electric energy. The current feedback module is configured to generate a second feedback signal based on a current of the delivered electric energy. The controller is configured to receive the first feedback signal and the second feedback signal, and to control the converter to receive and deliver the electric energy based on the first feedback signal and the second feedback signal. | 03-12-2015 |
20150085537 | CONTROL METHOD, POWER CONVERTING CIRCUIT AND AC-DC POWER CONVERTER USING THE SAME - In one embodiment, a method of controlling an AC-DC power converter, can include: (i) receiving, by a filter capacitor, a first branch current from an input current of the AC-DC power converter; (ii) receiving, by a power converting circuit, a second branch current from the input current; (iii) receiving, by the power converting circuit, a feedback signal that represents an output signal of the power converting circuit, and a triangular wave signal that is determined by the first branch current; (iv) generating a first conduction time based on the feedback signal such that the power converting circuit produces a first converting current; and (v) generating a second conduction time based on the triangular wave signal such that the power converting circuit produces a second converting current having a same absolute value as the first branch current. | 03-26-2015 |
20150085538 | INSULATED POWER SUPPLY APPARATUS - An insulated power supply apparatus includes an upper arm transformer which has a primary side coil and a secondary side coil, a lower arm transformer which has a primary side coil and a secondary side coil, and a power supply control section which has a voltage control switching element and an integrated circuit which turns on or off the voltage control switching element. At least one of the upper arm transformer and the lower arm transformer is adjacent to the power supply control section when viewing a surface of the substrate from a front thereof. An electric path transfers output voltage of the secondary side coil of the transformer adjacent to the power supply control section, to the integrated circuit. The integrated circuit turns on or off the voltage control switching element to perform feedback control so that the output voltage detected via the electric path reaches a target voltage. | 03-26-2015 |
20150098256 | CONTROLLER FOR ADJUSTING AN OUTPUT VOLTAGE OF A POWER CONVERTER AND RELATED METHOD THEREOF - A controller for adjusting an output voltage of a power converter includes a gate control signal generation circuit, a feedback signal detection module, and a reference voltage generation module. The gate control signal generation circuit generates a gate control signal to a power switch of a primary side of the power converter according to a reference voltage and a plurality of signals corresponding to the primary side and a secondary side of the power converter. The feedback signal detection module generates a logic signal according to a combination corresponding to the plurality of signals. The reference voltage generation module generates the reference voltage to the gate control signal generation circuit according to the logic signal. The power switch adjusts the output voltage of the secondary side of the power converter according to the gate control signal. | 04-09-2015 |
20150117072 | SOFT-START SWITCHING POWER CONVERTER - A soft-start switching power converter includes a voltage converting circuit and a soft-start circuit. The voltage converting circuit includes a transformer, and a first switch which includes a first terminal connected to the transformer, a second terminal providing a trigger signal, and a control terminal receiving a control signal, and which is controlled to switch between conduction and nonconduction, such that the transformer generates a feedback voltage. The soft-start circuit receives the trigger signal, generates the control signal according to the trigger signal, and determines whether or not to clamp the control signal at a preset voltage level based on the trigger signal. | 04-30-2015 |
20150311806 | METHOD AND CIRCUIT OF DETECTING ATTACHMENT AND DETACHMENT BETWEEN A PORTABLE DEVICE AND A POWER CONVERTER - A method and a circuit of detecting attachment and detachment between a portable device and a power converter are provided. The method and the circuit confirm attachment of the portable device to the power converter and generate an attachment signal. The method and the circuit further detect a bus voltage of the power converter for confirming detachment of the portable device from the power converter. | 10-29-2015 |
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 |
20150333633 | Single-Pole Switch Power Source - A single-stage switched-mode power supply comprises: a dual-source ac rectifying unit (501), for converting an alternating current input by an alternating current power source into at least two direct current sources, namely, a first direct current source (606) and a second direct current source (607); a combination switch unit, at least comprising a first switch circuit (603) and a second switch circuit (605), used for respectively performing power conversion on the first direct current source (606) and the second direct current source (607), to output a direct current, wherein the first direct current source (606) is connected to the first switch circuit (603) through an energy-storage capacitor (604), the first switch circuit (603) is any circuit capable of functioning as a switch circuit, and the second switch circuit (605) is a circuit capable of functioning as a flyback switch circuit. The single-stage switch power supply has complete power factor correction and output hold-up time, and further improves power source conversion efficiency. | 11-19-2015 |
20150372600 | CONVERTER AND METHOD FOR CONTROLLING THE SAME - A method for controlling converter such as a Flyback converter is disclosed. A load of the Flyback converter varies between zero and a peak value. The method includes: a load detecting step for detecting the load; and an operating mode control step for controlling the Flyback converter to switch between two or more of a continuous conduction mode, a valley conduction mode and a burst mode according to the load. A converter such as a Flyback converter is also provided. | 12-24-2015 |
20160006341 | TRAILING EDGE DETECTOR USING CURRENT COLLAPSE - A controller for a power converter compares a voltage sense signal to a first reference and compares a current sense signal to a current sense signal. The voltage sense signal is representative of an input voltage of the power converter. The current sense signal is representative of a current through the power converter. A slope of the voltage sense signal is measured over time. An edge detection is asserted by the controller when (1) the voltage sense signal is larger than the first reference, (2) the current sense signal is lower than the second reference, and (3) the slope is a negative slope. | 01-07-2016 |
20160079867 | TRAILING EDGE DETECTOR USING CURRENT COLLAPSE - A controller for a power converter includes an edge detection circuit including a first circuit coupled to coupled to compare a voltage sense signal representative of an input voltage to a first reference, and a second circuit coupled to compare a current sense signal representative of an input current to a second reference. A slope sense circuit is coupled to measure a slope of the voltage sense signal over time. An edge driver circuit is coupled to generate an edge signal that indicates that an edge has been determined when the voltage sense signal is greater than the first reference, the current sense signal is lower than the second reference, and the slope is negative. 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. | 03-17-2016 |
20160087539 | 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. An input for receiving an enable signal including enable events is 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 enable events and vary the current limit threshold in response to the enable events of the enable signal. | 03-24-2016 |
20160094131 | POWER CONVERTER WITH POWER FOLDBACK - A controller for use in a power converter includes a drive circuit coupled to control switching of a power switch of the power converter to regulate the output of the power converter. A limit sense circuit is coupled to output a limit sense signal in response to a condition of the power converter. The drive circuit is coupled to operate in a first operation mode if there is a no limit condition. The first operation mode includes regulating the output of the power converter with a regulated output voltage and a first maximum output current. The drive circuit is coupled to operate in a second operation mode if there is a limit condition. The second operation mode regulating the output of the power converter with the regulated output voltage and a second maximum output current wherein the second maximum output current is less than the first maximum output current. | 03-31-2016 |
20160134194 | PHASE ANGLE DETECTION MODULE FOR POWER CONVERTER - A power converter controller asserts a leading edge signal when a leading edge of a voltage signal is detected. The voltage sense signal is representative of an input voltage of the power converter. A trailing edge signal is asserted when a trailing edge of the voltage signal is detected. A first state of a threshold signal is generated when the voltage sense signal is at or above an upper threshold and generating a second state of the threshold signal when the voltage sense signal is at or below a lower threshold. A conduction signal is updated in response to the leading edge signal, the trailing edge signal, and the threshold signal. The conduction signal is for controlling a switch coupled to regulate an output of the power converter. | 05-12-2016 |
20160141961 | POWER CONVERTER CONTROLLER WITH STABILITY COMPENSATION - A switch mode power converter includes a primary side, an energy transfer element, and a secondary side. The secondary side includes output terminals coupled to a load and an output capacitance across the output terminals. The secondary side further includes a compensation signal generator—configured to generate a compensation signal. The compensation signal compensates charging the output capacitance with power transferred from the primary side to the secondary side. The secondary side further includes computational circuitry configured to output an adjusted compensation signal that compensates, based on the compensation signal, one of an output sense signal representative of an output signal at the output terminals and a reference signal representative of a desired output voltage of the switch mode power converter. The secondary side further includes a comparator to compare the adjusted compensation signal with the other one of the output sense signal and the reference signal. | 05-19-2016 |
20160181928 | INTEGRATED CIRCUIT WITH SELECTION BETWEEN PRIMARY SIDE VOLTAGE REGULATION AND SECONDARY SIDE VOLTAGE REGULATION | 06-23-2016 |
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