| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 363210140 | Having synchronous rectifier | 78 |
| 20080205090 | Isolated Dc-Dc Converter - A secondary-side rectifying and smoothing circuit rectifies and smoothes an output voltage from a secondary coil of a transformer and outputs a rectified and smoothed voltage to the outside. A tertiary-side rectifying and smoothing circuit rectifies and smoothes an output voltage from a tertiary coil to produce a direct-current voltage and detects and outputs the direct-current voltage as a detected voltage of the output voltage from the secondary-side rectifying and smoothing circuit. A control circuit controls the switching operation of a main switching device on the basis of the detected voltage so that the output voltage is stabilized. The secondary-side rectifying and smoothing circuit includes a rectification-side synchronous rectifier and a commutation-side synchronous rectifier as rectifying devices. The tertiary-side rectifying and smoothing circuit includes a commutation-side synchronous rectifier as a rectifying device that rectifies the output voltage from the tertiary coil, the commutation-side synchronous rectifier being switched on when the main switching device is turned off. | 08-28-2008 |
| 20080253150 | Flyback converter providing simplified control of rectifier MOSFETS when utilizing both stacked secondary windings and synchronous rectification - The present invention provides methods and systems for a flyback converter arranged with synchronous rectifier MOSFETS in such a manner that they operate with a common source potential while still providing for the use of a stacked output winding. With a common source potential, a single rectifier control voltage can be used to operate the rectifiers for multiple outputs greatly simplifying the control circuit. Advantageously, the present invention maintains the inherent simplicity of the flyback design while enabling designs with well-regulated multiple voltage outputs and the efficiency benefits of synchronous rectification. | 10-16-2008 |
| 20080266910 | POWER SUPPLY APPARATUS HAVING MULTIPLE OUTPUTS - A power supply apparatus having multiple outputs, a transformer, a first output circuit generating a first output voltage with respect to power transferred to a secondary side of the transformer, and a first output controller generating a first control signal to control a power supply provided to a primary side of the transformer, the apparatus including: a second output circuit to generate a second output voltage with respect to the power transferred to the secondary side of the transformer; and a second output controller to control 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 by turning off the second switch or feeding the second output voltage back to the second switch according to the first control signal. | 10-30-2008 |
| 20090027926 | METHOD AND APPARATUS TO PROVIDE SYNCHRONOUS RECTIFYING CIRCUIT FOR FLYBACK POWER CONVERTERS - A synchronous rectifying circuit is provided for flyback power converter. A pulse generator is utilized to generate a pulse signal in response to a leading edge and a trailing edge of a switching signal. The switching signal is used for switching the transformer of the power converter. An isolation device such as pulse transformer or small capacitors is coupled to the pulse generator for transferring the pulse signal through an isolation barrier of a transformer. A synchronous rectifier includes a power switch and a control circuit. The power switch is connected in between the secondary side of the transformer and the output of the power converter for the rectifying operation. The control circuit having a latch is operated to receive the pulse signal for controlling the power switch. | 01-29-2009 |
| 20090040794 | Time-Multiplexed Multi-Output DC/DC Converters and Voltage Regulators - A boost switching converter with multiple outputs includes an inductor is connected between an input supply (typically a battery) and a node V | 02-12-2009 |
| 20090109711 | Three-pin integrated synchronous rectifier and a flyback synchronous rectifying circuit - A three-pin integrated synchronous rectifier is the synchronous rectifier chip where the quantity of connection pins is the smallest possible quantity. The three-pin integrated synchronous rectifier uses a control pin to receive a control signal used as a power bias voltage and a synchronous pulse to make the synchronous rectifier chip operate normally. The control signal is obtained from the output pin of an auxiliary winding via a diode. The other pins are respectively the drain pin and the source pin of an internal power transistor and are connected with the output winding and the voltage output terminal for transmitting the power of the transformer to supply current for the loading. | 04-30-2009 |
| 20090129125 | SYNCHRONOUS REGULATION CIRCUIT - A primary-side switching circuit generates switching signals for switching a transformer. A secondary-side switching circuit is coupled to an output of the power converter to generate pulse signals in response to the switching signals and an output voltage of the power converter. Pulse signals are generated to rectify and regulate the power converter. A synchronous switch includes a power-switch set and a control circuit. The control circuit receives the pulse signals via capacitors for turning on/off the power-switch set. The power-switch set is connected in between the transformer and the output of the power converter. Furthermore, a flyback switch is operated to freewheel the inductor current of the power converter. The flyback switch is turned on in response to the off state of the power-switch set. The on time of the flyback switch is programmable and correlated to the on time of the power-switch set. | 05-21-2009 |
| 20090168465 | Power supply circuit with protecting circuit - A power supply circuit includes a direct current (DC) voltage source, a protecting circuit having a first switching element, a pulse width modulation (PWM) circuit having a first terminal, a switching circuit, and a transformer. The DC voltage source is configured to provide a first DC voltage. The first terminal is configured to receive the first DC voltage via the first switching element to enable the PWM circuit. The PWM circuit is configured to switch on or switch off the switching circuit. The transformer is configured to convert the first DC voltage to an alternating current (AC) voltage in cooperation with the switching circuit. | 07-02-2009 |
| 20090207637 | GENERATING DRIVE SIGNALS FOR A SYNCHRONOUS RECTIFICATION SWITCH OF A FLYBACK CONVERTER - In order to further develop a circuit arrangement ( | 08-20-2009 |
| 20090284995 | VOLTAGE DETECTING CIRCUIT AND SWITCHING POWER SOURCE APPARATUS - A voltage detecting circuit to perform voltage detection by introducing a voltage from a detection node, comprises: a first resistance, a second resistance, and a first switching element, connected in series with each other from the detection node to reference electric potential in order; and a detection circuit for performing a detection operation of a voltage by receiving input of the voltage from a node between the first resistance and the second resistance, wherein a control voltage generated on the basis of the voltage at the detection node is supplied to a control terminal of the first switching element, and the first switching element is turned on when the voltage at the detection node is large, and the first switching element is turned off when the voltage at the detection node is small. | 11-19-2009 |
| 20090290391 | SELF-DRIVEN SYNCHRONOUS RECTIFIER - A self-driven synchronous DC-DC converter ( | 11-26-2009 |
| 20100027298 | System and method for synchronous rectifier drive that enables converters to operate in transition and discontinuous mode - A synchronous rectifier is switched in accordance with a primary switch transition and a reference signal representing current in a current storage device to which the synchronous rectifier is coupled. A current emulator provides a signal representing current in the current storage device as a volt-second product so that current stored in the current storage device while the primary switch is on is discharged by the synchronous rectifier. The use of a current emulator provides an inexpensive solution for controlling synchronous rectifier transitions without resorting to more expensive current sensing solutions that are commercially impracticable. Blanking intervals are provided for avoiding false transitions of the synchronous rectifier when the primary switch turns on and after the synchronous rectifier turns off. The disclosed system and method can be applied to flyback converters for a synchronous rectifier on the secondary side of a transformer, or the inductor of buck converters. | 02-04-2010 |
| 20100033995 | FLYBACK CIRCUIT PROVIDING SYNCHRONIZED CONTROL - A flyback circuit providing synchronized control includes a pulse width modulation (PWM) unit, a synchronized control unit and an ON period limiting unit. The PWM unit generates a driving signal to control a switch ON period of a primary winding and provides a synchronized signal prior to the generation of the driving signal that has output time series ahead the driving signal. The synchronized control unit receives the synchronized signal through an induction winding to set off a synchronized commutation switch. The ON period limiting unit starts a period limiting time series after the synchronized commutation switch has been set on. After the synchronized commutation switch is set off by the synchronized signal the ON period limiting unit is reset to an initial condition. The synchronized commutation switch maintains an ON condition until the period limiting time series end, then the ON period limiting unit generates a forced ending signal to set off the synchronized commutation switch so that the flyback circuit maintains operation at a minimum duty frequency. | 02-11-2010 |
| 20100172158 | SWITCHING POWER SUPPLY APPARATUS AND PRIMARY SIDE CONTROL CIRCUIT - A synchronous rectification type DC-DC converter equipped with a burst mode prevents backward flows of currents on the secondary side thereof. The DC-DC converter turns off a control signal of a switching element on the primary side when the load thereof becomes light, and includes a voltage converting transformer, a first switching element connected to the primary side coil of the transformer, a primary side control circuit performing on-off control of the first switching element, a synchronously rectifying second switching element connected to the secondary side coil, and a secondary side control circuit performing on-off control of the second switching element. A pulse width ensuring circuit ensures that the pulse width of the control signal performing on-off control of the first switching element does not become equal to or less than the original width of a PWM pulse when entering the burst mode and when exiting the burst mode. | 07-08-2010 |
| 20100182806 | Controller for a Power Converter - A controller for a power converter having a transformer T | 07-22-2010 |
| 20100182807 | Synchronous Rectifier Circuit Capable of Preventing Flow-Through Current - A synchronous rectifier circuit (DC-DC converter) includes a CR integration circuit and a discharge circuit. The CR integration circuit outputs a voltage that varies at delayed timing as compared with a voltage induced in a secondary-side main winding. The discharge circuit discharges a gate voltage of a rectifier transistor as a result of conduction of a discharge transistor in response to the output voltage from the CR integration circuit. According to such a configuration, the rectifier transistor is turned off earlier than the timing of switching of polarity of voltages induced in the secondary-side main winding and a secondary-side auxiliary winding in response to turn-on of a primary-side transistor. | 07-22-2010 |
| 20110032732 | Secondary side post regulator of flyback power converter with multile outputs - A flyback power converter with multiple outputs has a transformer, a low-voltage output circuit, a high-voltage output circuit, and a secondary side post regulator circuit is provided. The transformer has a first secondary winding and a second secondary winding. The low-voltage output circuit has a low-voltage output capacitor and a rectifier unit, and is coupled to the first secondary winding to generate a low voltage output. The high-voltage output circuit has a high-voltage output switch and a high-voltage output capacitor, and is coupled to the second secondary winding to generate a high voltage output. The secondary side post regulator circuit adjusts on-time of the high-voltage output switch according to a feedback signal to have the energy stored in the high-voltage capacitor transmitted to the low-voltage capacitor to lower down the voltage level of the high output voltage. | 02-10-2011 |
| 20110032733 | DC-DC CONVERTER AND POWER SUPPLYING SYSTEM INCLUDING SAME - A DC-DC converter has a first-voltage-side port, a second-voltage-side port, and a third-voltage-side port, and performs, at different timings, an operation of boosting a first voltage to a third voltage and an operation of bucking a second voltage to the third voltage. A power supplying system includes a fuel cell, a secondary battery, an accessory system, the DC-DC converter, and another DC-DC converter connected between the fuel cell and a motor, and boosting the first voltage of the fuel cell to a fourth voltage to supply power to the motor through an inverter. The former DC-DC converter has the first-voltage-side port connected to the fuel cell, has the second-voltage-side port connected to the secondary battery, and has the third-voltage-side port connected to the accessory system. | 02-10-2011 |
| 20110267849 | FLYBACK POWER SUPPLY WITH FORCED PRIMARY REGULATION - A controller that forces primary regulation is disclosed. An example controller includes a switched element to be coupled to a second winding of an energy transfer element of a power supply. A secondary control circuit is coupled to the switched element. The secondary control circuit is to be coupled across an output of the second winding to switch the switched element in response to a difference between an actual output value at the output of the second winding and a desired output value to force a current in a third winding of the energy transfer element that is representative of the difference between the actual output value at the output of the second winding and the desired output value. A primary switch is to be coupled to a first winding of the energy transfer element. A primary control circuit is coupled to the primary switch. The primary control circuit is to be coupled to receive the current forced in the third winding of the energy transfer element in response to the secondary control circuit. The primary control circuit is coupled to switch the primary switch to regulate an output of the power supply coupled to the output of the second winding in response to the forced current. | 11-03-2011 |
| 20110310639 | FLYBACK POWER CONVERTER WITH MULTIPLE OUTPUTS AND A SECONDARY SIDE POST REGULATOR THEREOF - A flyback power converter with multiple outputs is disclosed. The flyback power converter has a transformer, a first output circuit, a second output circuit, and a secondary side synchronous rectification controller. The transformer has a primary side winding, a first output winding, and a second output winding. The first output circuit has a first output capacitor for storing electric energy from the first output winding. The second output circuit has a second rectifying switch and a second output capacitor. The second output capacitor is utilized for storing the electric energy from the second output winding. The secondary side synchronous rectification controller controls the conduction time of the second rectifying switch according to a detecting signal of a secondary-side conduction period. The electric energy in the first output capacitor may be transferred to the second output capacitor through the second output winding and the second rectifying switch and vice versa. | 12-22-2011 |
| 20120020123 | PREDICTIVE SYNCHRONOUS RECTIFICATION CONTROLLER, SWITCHING POWER CONVERTER WITH PREDICTIVE SYNCHRONOUS RECTIFICATION CONTROLLER AND CONTROLLING METHOD THEREOF - A predictive synchronous rectification controller for controlling at least one synchronous rectification switch is provided. The synchronous rectification controller has a ramp generator, a peak sampling unit, and an output control unit. The ramp generator receives a synchronous signal and generates a ramp signal accordingly. The peak sampling unit generates a predicted reference voltage signal by retrieving a peak voltage of the ramp signal. The output control unit compares the ramp signal with the predicted reference voltage signal to generate a synchronous rectification control signal to control a conducting state of the switch. | 01-26-2012 |
| 20120063175 | COMPENSATION CIRCUIT AND METHOD FOR A SYNCHRONOUS RECTIFIER DRIVER - Provided are circuits and methods for driving the synchronous rectifier (SR) of a power converter. A non-linear voltage sense compensator is applied across the drain and source of the SR, and a sense signal is provided to the SR driver sense input, such that false triggering of the SR is effectively eliminated. In addition, the voltage sense compensator ensures that the SR is turned on as soon as its current starts to flow and is turned off when its current falls to zero. The embodiments described herein may be incorporated into new VR designs, or they may be used to improve the SR driving characteristics of commercially available voltage sensing SR drivers. | 03-15-2012 |
| 20120243270 | FLYBACK DC-DC CONVERTER WITH FEEDBACK CONTROL - A flyback DC-DC converter is disclosed herein. The flyback DC-DC converter includes a transformer, a voltage divider and a controller. The transformer receives a DC input voltage and converts the DC input voltage to a DC output voltage. The voltage divider is coupled to a first secondary winding of the transformer, and generates a feedback signal indicative of the DC output voltage. The controller is coupled to the transformer via an input switching circuit and controls the input switching circuit to regulate the DC output voltage according to the feedback signal. A skip operation is triggered if the voltage of the feedback signal is higher than a preset reference voltage at the end of a turn-off period of the input switching circuit, and the voltage of the feedback signal is changed to zero during the skip operation. | 09-27-2012 |
| 20120281439 | FLYBACK POWER SUPPLY WITH FORCED PRIMARY REGULATION - A power supply includes an energy transfer element having first, second and third windings. An input of the first winding is coupled to an input of the power supply and an output of the second winding is coupled to an output of the power supply. A secondary control circuit is coupled across the second winding to switch a switched element coupled to the second winding in response to a difference between an actual output value and a desired output value to force a current in the third winding that is representative of the difference between the actual output value and the desired output value. A primary control circuit is coupled to a primary switch and to the third winding. The primary control circuit is coupled to switch the primary switch in response to the current forced in the third winding by the secondary control circuit. | 11-08-2012 |
| 20130003425 | DC/DC CONVERTER, AND ELECTRIC GENERATING SYSTEM USING SOLAR CELL HAVING THE SAME - Disclosed herein is an electric generating system using a solar cell which converts a voltage generated in the solar cell into an Alternating Current (AC) voltage, and applies the converted voltage to a power system. The electric generating system includes; a Direct Current (DC)/DC converter that converts the voltage generated in the solar cell into a DC voltage, and has a synchronous rectifier including a synchronous switch; and a controller that detects one of a phase and a voltage of the power system, and selectively connects the synchronous switch of the synchronous rectifier in accordance with one of the phase and voltage of the power system. Here, the electric generating system reduces a conduction loss, and increases overall efficiency of the electric generation system. | 01-03-2013 |
| 20130027987 | REGULATION CIRCUIT ASSOCIATED WITH SYNCHRONOUS RECTIFIER PROVIDING CABLE COMPENSATION FOR THE POWER CONVERTER AND METHOD THEREOF - A regulation circuit of a power converter for cable compensation according to the present invention comprises a signal generator generating a compensation signal in accordance with a synchronous rectifying signal. An error amplifier has a reference signal for generating a feedback signal in accordance with an output voltage of the power converter. The compensation signal is coupled to program the reference signal. The feedback signal is coupled to generate a switching signal for regulating an output of the power converter. The regulation circuit of the present invention compensates the output voltage without a shunt resistor to sense the output current of the power converter for reducing power loss. | 01-31-2013 |
| 20130107585 | Power Converter System with Synchronous Rectifier Output Stage and Reduced No-Load Power Consumption | 05-02-2013 |
| 20130121038 | CONVERTER, METHOD FOR CONTROLLING THE SAME, AND INVERTER - Disclosed herein are a converter, a method for controlling the same, and an inverter. The converter includes: an input terminal having power input thereto; a first converter unit converting the power input to the input terminal to thereby output the converted power to an output terminal; and a second converter unit connected between the input terminal and the output terminal while being in parallel with the first converter unit, wherein each of the first and second converter units includes an active clamp unit provided at a primary side thereof and a synchronous rectifying unit provided at a secondary side thereof. | 05-16-2013 |
| 20130128626 | Transformer Drive For Low Conduction Loss Rectifier In Flyback Converter - A flyback converter involves a bipolar transistor (BJT) and a parallel-connected diode as the rectifying element in the secondary side of the converter. The transformer of the converter has a primary winding, a first secondary winding, and a second secondary winding. A first end of the first secondary winding is coupled to the BJT base. A first end of the second secondary winding is coupled to the BJT collector and to the anode of the diode. The first and second secondary windings are wound such that when primary winding current stops, pulses of current flow out of the first ends of the first and second secondary windings. These currents are such that the BJT is maintained in saturation throughout at least most of the time current flows through the rectifying element, thereby achieving a low forward voltage across the rectifying element, reducing conduction loss, and increasing converter efficiency. | 05-23-2013 |
| 20130194836 | Isolated Flyback Converter With Efficient Light Load Operation - A flyback converter uses primary side sensing to sense the output voltage for regulation feedback. Such sensing requires a predetermined minimum duty cycle even with very light load currents. Therefore, such a minimum duty cycle may create an over-voltage condition. In the flyback phase, after a minimum duty cycle of the power switch at light load currents, a synchronous rectifier turns off approximately when the current through the secondary winding falls to zero to create a discontinuous mode. If it is detected that there is an over-voltage, the synchronous rectifier is turned on for a brief interval to draw a reverse current through the secondary winding. When the synchronous rectifier shuts off, a current flows through the primary winding via a drain-body diode while the power switch is off. Therefore, excess power is transferred from the secondary side to the power source to reduce the over-voltage so is not wasted. | 08-01-2013 |
| 20140003096 | SYNCHRONOUS RECTIFICATION CONTROL CIRCUIT AND POWER SUPPLY THEREOF | 01-02-2014 |
| 20140003097 | SWITCHING POWER SOURCE DEVICE | 01-02-2014 |
| 20140078788 | SYNCHRONOUS RECTIFYING CONTROL METHOD AND CIRCUIT FOR ISOLATED SWITCHING POWER SUPPLY - Disclosed are synchronous rectifying control methods and circuits for an isolated switching power supply. In one embodiment, a method can include: (i) generating a ramp voltage based on a power terminal voltage, where the power terminal voltage includes a voltage between first and second power terminals of a synchronous rectifier in the isolated switching power supply; (ii) determining whether the power terminal voltage starts declining; (iii) comparing the ramp voltage to a threshold voltage when the power terminal voltage starts to decline, where the threshold voltage substantially matches a minimum conduction time of the synchronous rectifier; (iv) reducing the ramp voltage and controlling the synchronous rectifier in an off state when the ramp voltage is lower than the threshold voltage; and (v) reducing the ramp voltage and controlling the synchronous rectifier in on state when the ramp voltage is higher than the threshold voltage. | 03-20-2014 |
| 20140092646 | Soft Switching Synchronous Quasi Resonant Converter - A switching circuit including a transformer having a primary and a secondary side; a first MOSFET switch coupled with the primary side; a primary current sensing device; a second MOSFET switch coupled with the secondary side; a secondary current sensing device; and a control circuit for driving the first and second MOSFET switches, wherein first and second switch are complementarily driven and wherein switching of the first and second MOSFET switches is controlled by the primary and secondary current sensing devices | 04-03-2014 |
| 20140112030 | METHOD AND A CONTROLLER FOR DETERMINING A DEMAGNETIZATION ZERO CURRENT TIME FOR A SWITCHED MODE POWER SUPPLY - In various embodiments a method is provided for determining a demagnetization zero current time for a switched mode power supply having a transformer, a first side and a second side being galvanically separated from each other and a switched mode power supply controller, the method including: determining a first voltage being applied to one side of the transformer; determining a second voltage provided at the other side of the transformer; determining a time the first voltage is provided to a winding of the transformer; and determining, by a circuit located on the same side of the transformer as the switched mode power supply controller, the demagnetization zero current time using the determined first voltage, the determined second voltage and the determined time. | 04-24-2014 |
| 20140112031 | CONTROL AND DRIVE CIRCUIT AND METHOD - Disclosed herein are control and drive circuits and methods for synchronous rectification switching power supply bias voltage generating circuits configured for a switching power supply. In one embodiment, a control and drive circuit can include: (i) a primary side switch controller configured to generate a primary side switch control signal; (ii) a logic circuit configured to generate a first control signal based on the primary side switch control signal; (iii) a converting circuit configured to generate a second control signal based on the first control signal; and (iv) a synchronous rectifier switch controller configured to generate a synchronous rectifier switch control signal based on the second control signal such that phases of the primary side switch control signal and the synchronous rectifier switch control signal are the same or inverse based on a topology of the synchronous rectification switching power supply. | 04-24-2014 |
| 20140126247 | SNUBBER CIRCUIT FOR DC-DC VOLTAGE CONVERTER - The invention relates to a DC-DC voltage converter ( | 05-08-2014 |
| 20140133192 | FLYBACK POWER CONVERTER AND ELECTRONIC APPARATUS - A flyback power converter is disclosed. The flyback power converter includes a voltage transformer, a main switch, a synchronous rectification switch, a synchronous rectification control circuit, a sampling circuit and an operation circuit. A control end of the main switch receives a main switch signal so as to control the main switch. The synchronous rectification control circuit transmits control signal to control end of the synchronous rectification switch according to sensing signal received. The sampling circuit samples the state of the synchronous rectification switch so as to generate first logic signal and second logic signal. The operation circuit executes timing for charging/discharging according to the first and the second logic-signal, so as to output switch cut-off pulse signal to a voltage-dividing circuit. If voltage of the sensing signal is lower than predetermined threshold voltage, the synchronous rectification switch enters into cut-off state according to the control signal. | 05-15-2014 |
| 20140185335 | POWER CONVERTER SYSTEM WITH SYNCHRONOUS RECTIFIER OUTPUT STAGE AND REDUCED NO-LOAD POWER CONSUMPTION - A power converter circuit may convert alternating current signals into direct current signals. A load may be powered from output terminals that are provided with the direct current signals. The power converter circuit may have a transformer with primary and secondary sides. A transistor on the primary side may be controlled using a pulse width modulation controller. A diode may be coupled in series with the secondary side of the transformer and the load. To improve efficiency at larger load currents, a synchronous rectifier control circuit may modulate a transistor on the secondary side that is coupled in parallel with the diode. The synchronous rectifier control circuit may monitor voltage pulses on the transistor on the secondary side or may make direct load current measurements to ascertain how much load current is flowing. Under low or no load conditions, synchronous rectification can be inhibited to improve efficiency. | 07-03-2014 |
| 20140192564 | SWITCHING POWER CONVERTING APPARATUS - A switching power converting apparatus is capable of converting an input voltage to an output voltage, and includes a transformer, a primary side control module, and a secondary side control module. The secondary side control module utilizes voltage clamping techniques or current-drawing techniques to stop self-excited conversion from the input voltage to the output voltage when the output voltage is greater than a predetermined target voltage, or utilizes a non-self-excited conversion architecture. | 07-10-2014 |
| 20140192565 | CIRCUIT WITH SYNCHRONOUS RECTIFIER FOR CONTROLLING PROGRAMMABLE 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. | 07-10-2014 |
| 20140198541 | POWER SUPPLY AND IMAGE FORMING APPARATUS - The power supply includes a transformer, a first switching element for performing a switching operation of turning on and off a voltage input to a primary side of the transformer, a second switching element to be connected to a secondary side of the transformer so as to be turned on and off in accordance with a voltage generated in the secondary side of the transformer, and a control unit for controlling an operation of the first switching element so that an output voltage of the secondary side of the transformer becomes a predetermined voltage. A conductive state period of the second switching element is adjusted to be longer as a frequency of the switching operation of the first switching element is higher. | 07-17-2014 |
| 20140204626 | RECEIVE CIRCUIT FOR USE IN A POWER CONVERTER - A receive circuit for use in a power converter controller includes a first amplifier coupled to receive an input pulse. A second amplifier is coupled to a first output of the first amplifier. The first output is coupled to be responsive to the input pulse and to a second output of the second amplifier. An output circuit is coupled to generate an output signal in response to the second output. | 07-24-2014 |
| 20140211517 | SWITCHING CONVERTER AND AC ADAPTER USING THE SAME - Disclosed herein is a switching converter capable of preventing a period in which a switch SW of a primary side is turned on and a period in which a synchronous rectifying switch SR SW of a secondary side is turned on from being overlapped with each other. The switching converter includes: a transformer T inducing primary energy to secondary side; a switch SW connected to a primary coil of the transformer T to switch a primary voltage; a synchronous rectifier SR connected to a secondary coil of the transformer T to rectify a secondary voltage; and a delay locked loop connected between the secondary coil and the synchronous rectifier SR, wherein the delay locked loop generates a signal synchronized with a turn-on control signal of the switch SW and outputs the generated signal to the synchronous rectifier SR to control a turn-off operation of the synchronous rectifier SR. | 07-31-2014 |
| 20140233272 | SYSTEM AND METHOD FOR SYNCHRONOUS RECTIFIER - A synchronous rectification circuit for a power supply includes a power switch for coupling to a secondary winding of a transformer of the power supply and an output capacitor of the power supply. The power switch includes a four-terminal MOSFET having a source, a drain, a gate, and a body. A body diode is formed by a junction between the body and the drain or by a junction between the body and the source. The body diode is coupled in parallel to the source and drain of the power transistor. A control circuit is configured to provide a control signal for controlling an on/off state of the power switch in response to a voltage condition of two terminals of the power switch. When the body diode makes a transition from reverse bias to forward bias, the control circuit causes the MOSFET to turn on, and when the forward bias voltage drops below a reference voltage, the control circuit causes the MOSFET to turn off. When the body diode makes a transition from forward bias to reverse bias, the control circuit causes the MOSFET to turn off | 08-21-2014 |
| 20140268915 | POWERING A SYNCHRONOUS RECTIFIER CONTROLLER - The embodiments herein describe a switched mode power converter. In particular, the embodiments herein disclose a method for powering a synchronous rectifier controller that enables synchronous rectification in the switched mode power converter. The synchronous rectifier controller may be enabled by a regulator circuit or directly from the output voltage. | 09-18-2014 |
| 20140268916 | ENERGY-SAVING CONTROL DEVICE - An energy-saving control device is disclosed. The control device is connected with an integrated circuit (IC) and a secondary winding of a transformer of a power converter. A primary winding of the transformer receives energy, and then the energy is discharged from the secondary winding and an energy signal of the energy is generated. And the energy signal comprises a high-frequency part and a low-frequency part thereafter. The energy signal is received by the energy-saving control device to control the operation of the IC according to a ratio of the low-frequency part to the high-frequency part. | 09-18-2014 |
| 20140362611 | ENERGY-SAVING POWER CONVERTER - A transformer primary side of a transformer starts storing energy when a first switch unit is turned on. A transformer secondary side auxiliary winding of the transformer generates a secondary side voltage. A voltage of a second input side of a comparison unit is higher than a voltage of a first input side of the comparison unit. The comparison unit is configured to turn off a second switch unit. The voltage of the second input side is lower than the voltage of the first input side when the first switch unit is turned off. The comparison unit is configured to turn on the second switch unit. A transformer secondary side of the transformer sends a secondary side current to a load apparatus through the second switch unit. | 12-11-2014 |
| 20140369086 | POWER SUPPLY APPARATUS AND IMAGE FORMING APPARATUS - The power supply apparatus includes a transformer, a switch element that drives a primary side of the transformer, and a control unit that controls a drive frequency of the switch element, wherein when a state of driving the switch element at a first drive frequency is shifted to a state of driving the switch element at a second drive frequency lower than the first drive frequency, the control unit turns on the switch element at a first timing in which a displacement amount of the transformer caused by the drive of the transformer becomes a first displacement amount and at a second timing in which the displacement of the transformer becomes a second displacement amount smaller than the first displacement amount. | 12-18-2014 |
| 20150049523 | METHOD FOR CONTROLLING SYNCHRONOUS RECTIFIER OF POWER CONVERTER AND CONTROL CIRCUIT USING THE SAME - The invention discloses a method for controlling a synchronous rectifier of a power converter and a control circuit using the same. The method includes the following steps. A control signal is generated to control a synchronous rectification transistor in response to an on-time of a switching signal, a level of a transformer voltage and an output voltage of the power converter. The switching signal is used for switching a transformer. The control signal is generated once the switching signal is turned off. A transformer signal is related to an input voltage of the power converter. The control signal is generated when the on-time of the switching signal is longer than a first time threshold. | 02-19-2015 |
| 20150117070 | AC-DC CONVERTING APPARATUS AND OPERATING METHOD THEREOF - An AC-DC converting apparatus and operating method are provided. The AC-DC converting apparatus includes a transformer, a first energy storage unit, a first output switch, a second energy storage unit, a second output switch and a secondary-side control module. The transformer includes a primary-side winding and a secondary-side winding. The first output switch is coupled between the secondary-side winding and the first energy storage unit. The second output switch is coupled between the secondary-side winding and the second energy storage unit. The secondary-side control module monitors the first energy storage unit and the second energy storage unit, and decides time length of a conduction period of the first output switch and the second output switch according to the monitoring result. | 04-30-2015 |
| 20150124494 | ADAPTIVE SYNCHRONOUS RECTIFIER CONTROL - The embodiments herein describe a switched mode power converter. In particular, the embodiments herein disclose techniques for adaptive synchronous rectification control. The switched mode power supply includes a synchronous rectifier controller that determines when to turn off the synchronous rectifier during each switching cycle based on a reference signal corresponding to when substantially all the power stored in a transformer of the power supply has been delivered to an electronic load. The synchronous rectifier controller may determine whether to adjust the reference signal used by the synchronous rectifier controller to turn off the synchronous rectifier during subsequent switching cycles. | 05-07-2015 |
| 20150124495 | REDUCING POWER CONSUMPTION OF A SYNCHRONOUS RECTIFIER CONTROLLER - The embodiments herein describe a switched mode power converter. In particular, the embodiments herein disclose techniques for reducing power consumption of a synchronous rectifier controller of the switched mode power converter. The switched mode power converter includes a plurality of circuit components that control operation of a synchronous rectifier included in the switched mode power converter. One or more of the circuit components may be disabled to reduce power consumption. | 05-07-2015 |
| 20150146457 | SYNCHRONOUS RECTIFIER CONTROLLER - Consistent with an example embodiment, a synchronous rectifier controller for a switched mode power supply comprises a transformer with a secondary side winding and a synchronous rectifier transistor with a gate, a source and a drain; the source and drain provide a conduction channel coupled to the secondary side winding. The controller comprises an input terminal for receiving an input signal related to a voltage at the drain, an output terminal configured to provide an output signal for setting a logic state of the gate, and circuitry having a first threshold and a second threshold. The circuitry is configured to generate the output signal and determine a time period in accordance in accordance with a comparison between the input signal and the first threshold; and in accordance with a comparison between the input signal and the second threshold, set the first threshold in accordance with the time period. | 05-28-2015 |
| 20150318790 | METHOD AND APPARATUS FOR SYNCHRONOUS RECTIFIER OPERATION - A method and synchronous rectifier controller uses minimum off and on time blanking to avoid switching the switching transistor at incorrect times responsive to transients in the current sense signal. The minimum off time timer is commenced only when the current sense signal is above a reset threshold, and is reset when the current sense voltage falls below the reset threshold. Resetting the minimum off time timer in this manner avoids false starts of the minimum off time timer due to transients and allows the SRC to properly synchronize with the conduction and blocking phases of rectifier operation. | 11-05-2015 |
| 20150333641 | CONTROL DEVICE OF SYNCHRONOUS RECTIFIER AND POWER SUPPLY - A power supply has a primary side and a secondary side electrically insulated from each other. A switching operation based on a switching of the primary side is controlled according to the power transmitted to the secondary side, and the switching operation is converted at a time earlier than a switching conversion time of the primary side by a predetermined time. | 11-19-2015 |
| 20150349652 | SYNCHRONOUS RECTIFICATION - This invention generally relates to synchronous rectifier controllers for an SMPS. One controller comprises: a sensor to sense a signal on a secondary side, to detect turn off of the switch; a charge source to, in response to a said detection, charge a control terminal of the rectifier to a voltage beyond a threshold voltage of the synchronous rectifier to allow the synchronous rectifier to conduct current of the secondary winding; and a linear amplifier having an output to sink current from the control terminal dependent on a difference between a voltage across the synchronous rectifier and an amplifier reference value, said voltage across the synchronous rectifier being a voltage across a controllable conduction path for current of the secondary winding, the linear amplifier to inhibit discharge of the control terminal from the voltage beyond the threshold voltage until the voltage across the synchronous rectifier reaches the amplifier reference value. | 12-03-2015 |
| 20160020703 | SYNCHRONOUS RECTIFICATION FOR FLYBACK CONVERTER - A flyback converter is described that includes a synchronous rectification integrated circuit (SRIC). The SRIC is configured to determine an actual turn-on time associated with a secondary switching element during an initial switching cycle and determine an error time that defines approximately a difference between the actual turn-on time and a predicted turn-on time associated with the secondary switching element. The predicted turn-on time defines approximately an amount of time to delay switching-off the secondary switching element after initially switching-on the secondary switching element, during an initial switching cycle of the secondary switching element. During a subsequent switching cycle of the secondary switching element, the SRIC is further configured to delay switching-off the secondary switching element for a period of time approximately equal to the predicted turn-on time and the error time. After delaying switching-off the secondary switching element the SRIC is configured to switch-off the secondary switching element. | 01-21-2016 |
| 20160036339 | INSULATION-TYPE SYNCHRONOUS DC/DC CONVERTER - Asynchronous rectifier controller is provided on a secondary side of an insulation-type synchronous DC/DC converter and controls the synchronous rectifier transistor. A driver circuit controls the synchronous rectifier transistor. A photo coupler connection terminal is coupled to an input side of the photo coupler. An error amplifier amplifies an error between a voltage detection signal according to an output voltage of the DC/DC converter and its target voltage, and to draw a current according to the error from an input side of the photo coupler via the photo coupler connection terminal. | 02-04-2016 |
| 20160036340 | INSULATION-TYPE SYNCHRONOUS DC/DC CONVERTER - The feedback IC is provided at the secondary side of the DC/DC converter and is coupled to the photo coupler. The error amplifier amplifies an error between a voltage detection signal according to an output voltage of the DC/DC converter and a target voltage, and draws a current according to the error from the input side of the feedback photo coupler via the photo coupler connection terminal. The abnormal detection circuit asserts an abnormal detection signal when an abnormal condition in a secondary side of the DC/DC converter is detected. The protection circuit is coupled to the photo coupler connection terminal, and acts on the feedback photo coupler via the photo coupler connection terminal so that a feedback operation by the error amplifier is invalid and an on-period of the switching transistor is shorten. | 02-04-2016 |
| 20160072399 | INSULATION-TYPE SYNCHRONOUS DC/DC CONVERTER - The synchronous rectifier controller is provided at the secondary side of the insulation-type synchronous DC/DC converter and controls the synchronous rectifier transistor. The controller is coupled to the output of the feedback photo coupler and drives the switching transistor according to the feedback signal. The synchronous rectifier controller includes a driver circuit and an abnormal detection circuit and is configured as a single module. The driver circuit drives the synchronous rectifier transistor. The abnormal detection circuit detects an abnormal condition in the secondary side of the DC/DC converter. FAIL terminal is coupled to notify outside of an occurrence of the abnormal condition. | 03-10-2016 |
| 20160079874 | CONSTANT ON-TIME (COT) CONTROL IN ISOLATED CONVERTER - A constant on-time isolated converter comprising a transformer is disclosed. The transformer primary side connects to an electronic switch and secondary-side connects to a load and a processor. The processor connects to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal. The driver receives control signal through the coupling element and accordingly changes the electronic switch ON/OFF state, regulating output voltage and current via the transformer, where the electronic switch ON/OFF duration is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed response to load transient. | 03-17-2016 |
| 20160079875 | CONSTANT ON TIME COT CONTROL IN ISOLATED CONVERTER - The present invention discloses a constant on-time isolated converter comprising a transformer with a primary side and a secondary side. The primary side is connected to an electronic switch and secondary-side is connected to a load and a processor. The processor is connected to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal accordingly. The driver receives the control signal through the coupling element and accordingly changes the ON/OFF state of the electronic switch, regulating the output voltage and the output current via the transformer, where the duration of the ON/OFF state of the electronic switch is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed load transient response. | 03-17-2016 |
| 20160079876 | CONSTANT ON-TIME (COT) CONTROL IN ISOLATED CONVERTER - The present invention discloses a constant on-time isolated converter comprising a transformer with a primary side and a secondary side. The primary side is connected to an electronic switch and secondary-side is connected to a load and a processor. The processor is connected to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal accordingly. The driver receives the control signal through the coupling element and accordingly changes the ON/OFF state of the electronic switch, regulating the output voltage and the output current via the transformer, where the duration of the ON/OFF state of the electronic switch is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed load transient response. | 03-17-2016 |
| 20160079877 | CONSTANT ON-TIME (COT) CONTROL IN ISOLATED CONVERTER - The present invention discloses a constant on-time isolated converter comprising a transformer with a primary side and a secondary side. The primary side is connected to an electronic switch and secondary-side is connected to a load and a processor. The processor is connected to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal accordingly. The driver receives the control signal through the coupling element and accordingly changes the ON/OFF state of the electronic switch, regulating the output voltage and the output current via the transformer, where the duration of the ON/OFF state of the electronic switch is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed load transient response. | 03-17-2016 |
| 20160079878 | CONSTANT ON TIME (COT) CONTROL IN ISOLATED CONVERTER - The present invention discloses a constant on-time isolated converter comprising a transformer with a primary side and a secondary side. The primary side is connected to an electronic switch and secondary-side is connected to a load and a processor. The processor is connected to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal accordingly. The driver receives the control signal through the coupling element and accordingly changes the ON/OFF state of the electronic switch, regulating the output voltage and the output current via the transformer, where the duration of the ON/OFF state of the electronic switch is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed load transient response. | 03-17-2016 |
| 20160087546 | SYNCHRONOUS RECTIFICATION CONTROL CIRCUIT AND POWER SUPPLY THEREOF - In one embodiment, a synchronous rectification control circuit in a flyback converter, can include: a first control circuit that receives a drain-source voltage signal of a synchronous rectifier switch and a flyback converter output voltage, and generates a first control signal based on a conduction time of a primary-side power switch; a second control circuit configured to receive the drain-source voltage signal, and to generate a second control signal; when the primary-side power switch is turned off, and the first control signal is greater than a threshold value, the second control signal controls a switching operation of the synchronous rectifier switch; and when the primary-side power switch is turned off, and the first control signal is less than the threshold value, the synchronous rectifier switch is configured to stop operation, before the primary-side power switch is turned on again. | 03-24-2016 |
| 20160105122 | SYNCHRONOUS RECTIFICATION CONTROLLER AND POWER CONVERTER USING THE SAME - A synchronous rectification controller and a power converter using the same may prevent malfunction at the time of an initial operation. The synchronous rectification controller may include a sensing unit sensing a magnitude of a driving current, and a driving unit outputting a rectification control signal which controls an operation of the rectification unit by the driving current sensed by the sensing unit. A flow of the driving current in the rectification unit may be selectively cut off, depending on a magnitude of a driving voltage of the synchronous rectification controller. | 04-14-2016 |
| 20160126853 | Partial Time Active Clamp Flyback - A method is shown to improve the resonant transition controlled flyback converter presented in Ser. No. 14/274,598 (Exhibit A) by adding a clamp circuit that recycles the leakage energy. By utilizing the particular advantages of the resonant transition controlled flyback converter an optimized clamp capacitor can be used to increase the efficiency of the converter further. | 05-05-2016 |
| 20160141968 | RECEIVE CIRCUIT FOR USE IN A POWER CONVERTER - A multi-die isolated integrated circuit controller includes a magnetically coupled communication link, a transmitter circuit coupled to the magnetically coupled communication link, and a receiver circuit coupled to the magnetically coupled communication link. The transmitter circuit is galvanically isolated from the receiver circuit. The transmitter circuit is coupled to send an input pulse to the receiver circuit by way of the magnetically coupled communication link. The receiver circuit is coupled to receive a receiver voltage by way of the magnetically coupled communication link to generate an output voltage in response to the receiver voltage and a threshold voltage. | 05-19-2016 |
| 20160172962 | FLYBACK CONVERTER OPERATING BY SYNCHRONOUS RECTIFICATION WITH TRANSIENT PROTECTION, PRIMARY SIDE CONTROL CIRCUIT THEREIN, AND CONTROL METHOD THEREOF | 06-16-2016 |
| 20160181934 | INSULATED SYNCHRONOUS RECTIFICATION DC/DC CONVERTER | 06-23-2016 |
| 20160181935 | ISOLATED DC/DC CONVERTER, POWER SUPPLY, POWER SUPPLY ADAPTOR, ELECTRONIC DEVICE USING THE SAME, AND PRIMARY SIDE CONTROLLER | 06-23-2016 |
| 20160190942 | INSULATED SYNCHRONOUS RECTIFICATION DC/DC CONVERTER - When a pulse generator detects that a switching transistor on a primary side of a DC/DC converter turns off, the pulse generator sets a pulse signal S | 06-30-2016 |
| 20160190947 | POWER CONVERSION APPARATUS WITH POWER SAVING AND HIGH CONVERSION EFFICIENCY MECHANISMS - A power conversion apparatus is provided. The power conversion apparatus includes a transformer, a synchronous rectification (SR) transistor and an SR control circuit. A first terminal of a primary side of the transformer receives an input voltage. A first terminal of a secondary side of the transformer provides an output voltage to a load. A first drain/source terminal of the SR transistor is coupled to a second terminal of the secondary side of the transformer. A second drain/source terminal of the SR transistor is coupled to a first ground terminal. A gate terminal of the SR transistor receives a control signal. The SR control circuit receives a signal of the first drain/source terminal of the SR transistor to determine statuses of the load and generate the control signal. When the load is a light load, the SR control circuit enters a power-saving mode and turns off the SR transistor. | 06-30-2016 |
| 20160190948 | SHOOT-THROUGH PREVENTION IN SWITCHED-MODE POWER SUPPLIES - The disclosed embodiments provide a system that operates a flyback converter. During activation of a synchronous rectifier (SR) controller on a secondary side of the power converter, the system temporarily disables driving of a gate of a metal-oxide-semiconductor field-effect transistor (MOSFET) by the SR controller to enable synchronization of the SR controller to a switching frequency on a primary side of the power converter. After driving of the gate of the MOSFET by the SR controller has been disabled for a pre-specified period, the system enables driving of the gate of the MOSFET by the SR controller. | 06-30-2016 |
| 20160190949 | SYNCHRONOUS RECTIFICATION - A controller for a use with a power converter includes a sensor coupled to sense a signal on a secondary side of the power converter. The sensor is coupled to detect a turn off of a power switch on a primary side of the power converter. A charge source is coupled to charge a control terminal of a synchronous rectifier on the secondary side of the power converter in response to said detection of the turn off of the power switch to a voltage beyond a threshold voltage of the synchronous rectifier to allow the synchronous rectifier to conduct a current of the secondary winding. A linear amplifier having an output is coupled to sink current from the control terminal of the synchronous rectifier in response to a difference between a voltage across the synchronous rectifier and an amplifier reference value. | 06-30-2016 |
| 20190149032 | ZVS CONTROL CIRCUIT FOR USE IN A FLYBACK POWER CONVERTER | 05-16-2019 |
