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Synchronous Rectifier patents

      

This page is updated frequently with new Synchronous Rectifier-related patent applications.




 Synchronous rectifier patent thumbnailSynchronous rectifier
Disclosed is a method to control the synchronous rectification in a power converter including a primary winding and a secondary winding, including detecting a peak current in a secondary winding, determining a blanking threshold based on the peak current, and blanking a turning off of a synchronous rectifier (sr) switch for a blanking time based on the blanking threshold.. .

 Digitalized double-excitation uninterrupted switching power supply patent thumbnailDigitalized double-excitation uninterrupted switching power supply
A digitalized double-excitation uninterrupted switching power supply comprises a main transformer provided with a primary coil and a secondary coil, a main loop, a synchronous rectification output loop, a synchronous direct-current converter and a digital control unit, wherein the main loop comprises a high-voltage switching network, a resonant inductor, the primary coil and a resonant capacitor. The synchronous rectification output loop comprises a current-doubler rectifier formed by connecting two synchronous rectifier tubes in series oppositely and the secondary coil in parallel, and a filter circuit connected to two output ends of the current-doubler rectifier.

 Self supply for synchronous rectifiers patent thumbnailSelf supply for synchronous rectifiers
A power converter with an isolated topology may include a primary side and a secondary side. The secondary side includes a self-powered synchronous rectifier.
Infineon Technologies Austria Ag


 Synchronous rectifier circuit and control method thereof patent thumbnailSynchronous rectifier circuit and control method thereof
A synchronous rectifier circuit can include: a full-bridge rectifier circuit having first, second, third, and fourth switches, where a common node of the first and fourth switches is configured as a first input terminal of the synchronous rectifier circuit, and a common node of the second and third switches is configured as a second input terminal of the synchronous rectifier circuit; a switching control circuit configured to generate a first control signal to control the first and third switches, and a second control signal to control the second and fourth switches; and the switching control circuit being configured to self-adjust the first and second control signals to control operating points of the first, second, third, and fourth switches to be approximately ideal operating points.. .

 Synchronous rectifier for buck converter without the need for a comparator patent thumbnailSynchronous rectifier for buck converter without the need for a comparator
A switch mode power supply, which functions in a continuous current mode and a discontinuous mode employing a zero crossing control circuit for determining a polarity of an inductor current and from the polarity of the inductor current, controlling an operational state of a switching section of the switch mode power supply such that the inductor current becomes approximately zero amperes at the end of each demagnetization phase of operation.. .
Dialog Semiconductor (uk) Limited


 System and  bidirectional wireless power transfer patent thumbnailSystem and bidirectional wireless power transfer
The present invention relates to a wireless power supply system including a remote device capable of both transmitting and receiving power wirelessly. The remote device includes a self-driven synchronous rectifier.
Access Business Group International Llc


 Voltage discharge circuit patent thumbnailVoltage discharge circuit
Technologies are described for an adaptable power supply that can switch between two or more output voltages. The power supply includes discharge circuitry that utilizes the secondary windings of a transformer as a discharge path when the power supply switches from a high voltage level to a low voltage level.
Microsoft Technology Licensing, Llc


 Secondary control device and charging system having the same patent thumbnailSecondary control device and charging system having the same
A secondary control device and a charging system are provided. The secondary control device is connected with a transformer having a secondary winding connected with a charging interface, and includes: a secondary rectifier switch connected with the secondary winding; a secondary synchronous rectifier chip connected with the secondary winding and the secondary rectifier switch, and configured to detect a voltage between two terminals of the secondary rectifier switch, to control the secondary rectifier switch to turn on or turn off according to the voltage, to control the secondary rectifier switch to turn on again when the secondary rectifier switch is in an off-state so as to control the secondary winding to generate a mutation voltage, to obtain a transmission signal on the charging interface, and to control a driving voltage of the secondary rectifier switch according to the transmission signal so as to adjust the mutation voltage..
Byd Company Limited


 Isolated synchronous rectification control circuit, control device, and control method patent thumbnailIsolated synchronous rectification control circuit, control device, and control method
The present invention provides an isolated synchronous rectification control circuit, a control device, and a control method. The control circuit includes a power supply module, a reference module, a comparator module, a primary side turn-on determination unit, a secondary intermittent burst estimation unit, a logic unit, and a driver unit.
Wuxi Chip Hope Micro-electronics Ltd


 High frequency multi-level rectification patent thumbnailHigh frequency multi-level rectification
A multi-level rectifier is presented that is suitable for use at high frequencies, including into mhz range such as in the 6.78 mhz band used for wireless power transfer. To maintain the proper timing or switching waveform when operating at high frequencies, a feedback loop is used.
Qualcomm Incorporated


Multi-impedance rectification for wireless power transfer

A multi-level rectifier is presented that is suitable for use at high frequencies, including into mhz range such as in the 6.78 mhz band used for wireless power transfer. Depending on the amplitude of the input waveform, the rectifier can be operated in different modes.
Qualcomm Incorporated

System and controlling a synchronous rectifier

A power system includes dc-dc power conversion circuitry that has a first switch and a second switch on either side of a transformer, and the second switch is operates as a synchronous rectifier. Power transfer from a primary side to secondary side of the dc-dc power conversion circuitry is controlled by operating the first switch.
Toyota Motor Engineering & Manufacturing North America Inc.

Gate pre-positioning for fast turn-off of synchronous rectifier

A synchronous rectifier driver pre-positions a gate of a synchronous rectifier to allow for fast turn-off. The synchronous rectifier driver turns on the synchronous rectifier by driving the gate at a high level for a period of time that is based on a previous conduction time of the synchronous rectifier.
Fairchild Semiconductor Corporation

Devices, systems, and methods for adjusting output power using synchronous rectifier control

Methods and apparatus are disclosed for wirelessly receiving power. In one aspect, an apparatus for wireless receiving power is provided.
Qualcomm Incorporated

Self-tuning adaptive dead time control for continuous conduction mode and discontinuous conduction mode operation of a flyback converter

A flyback converter includes a primary-side switch that controls conduction of current on a primary side of a transformer and a synchronous rectifier on a secondary side of the transformer. A synchronous rectifier driver controls the conduction of the synchronous rectifier by adaptively adjusting a turn-off threshold of the synchronous rectifier..
Fairchild Semiconductor Corporation

Adaptive turn-off trigger blanking for synchronous rectification

A switching converter includes a synchronous rectifier and a synchronous rectifier driver that controls conduction of the synchronous rectifier. The synchronous rectifier driver turns off the synchronous rectifier in response to a turn-off trigger.
Fairchild Semiconductor Corporation

Synchronous rectifier applied to a power converter and operation method thereof

A synchronous rectifier applied to a power converter includes a power supply module, a control module, and a gate driving unit. The power supply module is used for generating a supply current according to an induced voltage generated from a secondary side of the power converter, wherein the supply current is used for establishing a supply voltage, and the induced voltage corresponds to a control signal of a power switch of a primary side of the power converter.
Leadtrend Technology Corp.

Self-driven ac-dc synchronous rectifier for power applications

Systems, methods, and devices that employ self-driven gate-drive circuitry to facilitate controlling power switches to emulate a diode bridge to synchronously rectify a power signal are presented. A single-phase or multi-phase synchronous rectifier can comprise at least a first pair of switches of a first conducting path and a second pair of switches of a second conducting path that can form or emulate a diode bridge.
City University Of Hong Kong

Control of asymmetric parallel synchronous rectifiers in power converter topologies

A power converter includes an input power source, a synchronous rectifier and a controller. The synchronous rectifier includes a plurality of actively controlled switches coupled in parallel and configured to rectify current delivered from the input power source to a load.
Infineon Technologies Austria Ag

Secondary side controlled control circuit for power converter with synchronous rectifier

A secondary side controlled control circuit for power converter with synchronous rectifier is provided. The secondary side controlled control circuit comprises a primary side controller and a secondary side controller.
Fairchild (taiwan) Corporation

High speed synchronous rectifier

A control circuit and method for a synchronous rectifier having a plurality of switches and receiving an ac input signal. The control method includes switching between controlling a first switch of the plurality of switches in response to a control signal for a second switch of the plurality of switches, controlling the first switch in response to a comparison between the ac input signal and a second signal..

Wireless power transfer receiver having synchronous rectifier synchronized to wireless power transfer signal

An apparatus for wirelessly receiving power via a wireless field generated by a transmitter includes a resonator configured to generate electrical current to power or charge a load based on a voltage induced in the resonator in response to the wireless field, a controller configured to receive a synchronization timing reference signal based on a derivative of the voltage induced in the resonator, the controller configured to generate a rectifier control signal based on the synchronization timing reference signal, and a synchronous rectifier configured to switch responsive to the rectifier control signal.. .

System and improving efficiency for quasi-square wave power converters

A power converter includes a power stage having a switch-node of a switched-mode power supply that is coupled to an input voltage node by a power field-effect transistor (fet) to energize an inductive circuit and is coupled to a ground node by a synchronous rectifier in parallel with the inductive circuit. The power converter also includes a controller coupled to the power stage.
Texas Instruments Incorporated

Driver circuit for synchronous rectifier switches in resonant converters, corresponding converter and method

A driver circuit for synchronous rectifier electronic switches, such as sr mosfets in resonant converters controls a pair of synchronous rectifier electronic switches to apply thereto a drive voltage to switch the synchronous rectifier electronic switches on and off synchronously with a converter current. The driver circuit includes a programming module to produce a first signal indicative of the figure of merit of the synchronous rectifier electronic switches, and, optionally, a current sensing module to produce a second signal indicative of the output current of the synchronous rectifier electronic switches.
Stmicroelectronics S.r.l.

Synchronous rectifier applied to a power converter and operation method thereof

A synchronous rectifier applied to a power converter includes a gate coupling effect suppressing unit. The gate coupling effect suppressing unit is used for suppressing an induced voltage coupled to a gate of a metal-oxide-semiconductor transistor coupled to a secondary side of the power converter to ensure that the metal-oxide-semiconductor transistor is turned off when the power converter operates in a start-up condition and a power switch of the power converter is turned on.
Leadtrend Technology Corp.

Adaptive synchronous rectifier control

A switching power converter may include a power switch coupled to a primary winding of a transformer, and a primary controller configured to turn on and off the power switch, a synchronous rectifier switch coupled to a secondary winding of a transformer, and a synchronous rectifier controller configured to turn on and off the synchronous rectifier switch. The synchronous rectifier controller may monitor a voltage across the synchronous rectifier switch.
Dialog Semiconductor Inc.

Method and device for detecting conduction mode

A method and a device for detecting conduction mode is disclosed. The method uses an energy-storing element to connect with a synchronous rectifier and a load, and the load connects with the synchronous rectifier.
Sync Power Corp.

Flyback converter with secondary side regulation

Disclosed examples include flyback converters, control circuits and methods to facilitate secondary side regulation of the output voltage. A primary side control circuit operates a primary side switch to independently initiate power transfer cycles to deliver power to a transformer secondary winding in a first mode.
Texas Instruments Incorporated

Synchronous rectifier phase control to improve load efficiency

A semiconductor device includes a current monitor circuit to measure a load current. A controller controls drive signals having a signal phase to operate a synchronous rectifier (sr) circuit based on the measured load current from the current monitor circuit.
Texas Instruments Incorporated

Power converter and control method therefor

A power converter and a control method therefor are provided. The power converter includes a transformer, synchronous rectifier and a control circuit.
Fairchild (taiwan) Corporation

Devices, systems, and methods for adjusting output power using synchronous rectifier control

In one aspect, an apparatus for wireless receiving power comprises a receive circuit configured to receive wireless power via a magnetic field sufficient to power or charge a load. The apparatus further comprises a tuning circuit comprising a variable reactive element, coupled to the receive circuit, and configured to detune the receive circuit away from a resonant frequency to adjust an output power level to a first output power level.
Qualcomm Incorporated

Method and obtaining soft switching in all the switching elements through current shaping and intelligent control

A method is shown to create soft transition in selected topologies by preserving the leakage inductance energy during the dead time and using several techniques to supplement the energy require to discharge the parasitic capacitance of the primary switchers and obtain zero voltage switching. One technique consists in a current pulse injection across the synchronous rectifiers during the dead time and prior the turn off of the synchronous rectifiers.
Rompower Energy Systems, Inc.

Synchronous rectifier and control circuit thereof

A synchronous rectifier includes: a rectifying circuit including transistors, the rectifying circuit being configured to generate rectified power by rectifying input power input to an input terminal of the rectifying circuit depending on switching operations of the transistors, and output the rectified power to an output terminal of the rectifying circuit; and a controller configured to apply a gate signal to each of the, and adjust a pulse width of the gate signal depending on a difference between the input power and the gate signal.. .
Research & Business Foundation Sungkyunkwan University

Dead time compensation for synchronous rectifiers in adaptive output powers

A synchronous rectifier controller for an adaptive output power converter is provided. The synchronous rectifier controller includes a voltage detection circuit, a threshold generation circuit, and a driver.
Fairchild (taiwan) Corporation

Synchronous rectifier circuit

A first variable voltage source vs1 generates a first threshold voltage vzc1 which is variable. A first zero current detection comparator zc_cmp1 compares a first voltage vac1 at a first input node ac1 with the first threshold voltage vzc1, and generates a zc_det1 signal which indicates a comparison result.
Rohm Co., Ltd.

Insulation-type synchronous dc/dc converter

A synchronous 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.
Rohm Co., Ltd.

System and synchronous rectification with enhanced detection of small currents

A system and method of synchronous rectification includes a synchronous rectifier circuit. The synchronous rectifier circuit includes a direct current (dc) load coupled between a dc output node and a ground node, an alternating current (ac) source applying an ac waveform to an ac input node, an upper switch coupled between the dc output node and the ac input node, and a lower switch coupled between the ac input node and the ground node.
Integrated Device Technology, Inc.

Synchronous start-up of parallel power converters in a switched-mode power supply

Methods and apparatuses for controlling synchronous start-up of power converters arranged in parallel in droop load share switched-mode power supplies are described. In one embodiment, a method may be performed by circuitry in a dc-dc power converter.
Telefonaktiebolaget L M Ericsson (publ)

Capacitive sensing device

A capacitive sensing device comprises an antenna electrode for emitting an alternating electric field in response to an alternating voltage caused in the antenna electrode and a control and evaluation circuit that comprises a transimpedance amplifier configured to maintain the alternating voltage equal to an alternating reference voltage on a reference voltage node by injecting a current into the antenna electrode and to measure the current. The control and evaluation circuit comprises a microcontroller and a multiplexer configured and arranged to switch the antenna electrode alternately to a current input of the transimpedance amplifier and to the alternating reference voltage node.
Iee International Electronics & Engieering S.a.

Wireless power receiver with programmable power path

A synchronous rectifier using only n-channel devices in which the low-side switches are effectively cross-coupled using low-side comparators and the high-side switches perform an accurate zero-voltage-switching (zvs) comparison. The charging path of each bootstrap domain is completed through the low-side switches, which are each always on for every half-cycle independent of loading.
Mediatek Singapore Pte. Ltd.

Body diode conduction optimization in mosfet synchronous rectifier

To maximize power efficiency, dead time between “on” times of a synchronous rectifier (“sr”) mosfet switch and a main switch for ccm operation in particular in isolated and non-isolated self-driven synchronous dc-dc converters needs to be optimized. To accomplish that objective, the latest conduction time t of a body diode of the sr mosfet following conduction thereof is determined, compared with a selected fixed optimum period t1, and incrementally or decrementally adjusted in a subsequent switching cycle while t is unequal to t1, depending on whether t is shorter or longer than t1, so that t eventually is made substantially equal to t1 in length.
Joulwatt Technology Inc Limited

Circuit and driving synchronous rectifiers for high-frequency flyback converters

A voltage waveform similar to a waveform of a magnetizing current of an isolation transformer and immune to high frequency oscillatory resonant behavior is developed across a capacitor of a series resistor and capacitor connection connected in parallel with a synchronous rectifier. A simple logic circuit produces a waveform for controlling the synchronous rectifier which is not subject to significant turn on delay or early turn off caused by oscillatory resonances among parasitic inductances and capacitances.
Virginia Tech Intellectual Properties, Inc.

Switching power supply device

A switching power supply device having a synchronous rectifier ic on a secondary side, responds to an anomaly on a primary side based on detecting an occurrence of the anomaly on the secondary side. When a secondary side synchronous rectifier ic detects an anomaly, a current is output from the anomaly-time current output terminal of the secondary side synchronous rectifier ic.
Fuji Electric Co., Ltd.

Dynamic reduction of synchronous rectifier power losses

Methods and circuits for controlling a synchronous rectifier. An operating condition of the synchronous rectifier is detected.
Mediatek Inc.

Synchronous rectifier

Various embodiments may relate to a synchronous rectifier including at least one rectifier cell, to which power is supplied via a secondary winding of a transformer arranged between the input connections of the synchronous rectifier. The rectifier cell comprises a bipolar main switch operated in the inverse mode, wherein an energy store is provided in the base line of the bipolar main switch, which energy store, in conjunction with an auxiliary switch which is concomitantly controlled by the relevant secondary winding for the bipolar main switch, ensures that the main switch is switched off prior to the end of the inverse phase..
Osram Gmbh

Soft switching flyback converter

Disclosed examples include synchronous rectifiers and flyback converters, integrated circuits and operating methods, in which a first switch is turned on to allow current to flow for a first time period in a first direction in a transformer primary winding responsive to a first switch voltage transitioning below a first threshold, and a second switch is turned on for a second time period after the first time period to transfer energy from a secondary transformer winding to drive a load. In the same converter cycle, the second switch is again turned on for a third time period in response to a second switch voltage transitioning below a second threshold at one of a series of troughs of a resonant ringing voltage waveform across the second switch, to cause current flow in a second direction in the primary winding to discharge a capacitance of the first switch to cause the first switch voltage to transition below the first threshold to initiate a subsequent converter cycle..
Texas Instruments Incorporated

Synchronous rectifier for buck converter without the need for a comparator

A switch mode power supply, which functions in a continuous current mode and a discontinuous mode employing a zero crossing control circuit for determining a polarity of an inductor current and from the polarity of the inductor current, controlling an operational state of a switching section of the switch mode power supply such that the inductor current becomes approximately zero amperes at the end of each demagnetization phase of operation.. .
Dialog Semiconductor (uk) Limited

Self supply for synchronous rectifiers

A power converter with an isolated topology may include a primary side and a secondary side. The secondary side includes a self-powered synchronous rectifier.
Infineon Technologies Austria Ag

Apparatus and driving synchronous rectifier

Provided is apparatus and a method for driving synchronous rectifiers, which relate to the field of power supplies for communications. The apparatus includes: detection circuits, wherein each of the detection circuits is configured to detect drain and source voltages of one of synchronous rectifiers to obtain a detection signal for indicating a current direction in the one of the synchronous rectifiers; an isolated driving circuit, configured to generate isolated driving signals for driving the synchronous rectifiers according to the detection signals output by the detection circuits; and the synchronous rectifiers, configured to synchronously rectify input signals from a main transformer by using the isolated driving signals.
Zte Corporation

Reducing switching losses associated with a synchronous rectification mosfet

A synchronous rectifier is described that includes a transistor device that has a gate terminal, a source terminal, a drain terminal, and a field-plate electrode. The field-plate electrode of the transistor device includes an integrated diode.
Infineon Technologies Austria Ag

In-vehicle charger

A si diode is used as a rectifying diode on a transformer secondary side of an isolated dc/dc converter, and a high-voltage schottky barrier diode made of a wide bandgap semiconductor is used as a free-wheeling diode arranged between a rectifier circuit and a smoothing reactor. Thus, there may be provided an in-vehicle charger capable of suppressing a diode recovery surge voltage with a circuit configuration that is simpler and suppressed in cost increase as compared to a case where a related-art synchronous rectifier circuit system is employed..
Mitsubishi Electric Corporation

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.

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.

Resonant converters with synchronous rectifier feedback

A method comprises detecting a signal representing a drain-to-source voltage of a switch of a synchronous rectifier of an inductor-inductor-capacitor (llc) resonant converter, comparing the signal with a predetermined threshold, generating a first logic state if the drain-to-source voltage is greater than the predetermined threshold, generating a second logic state if the drain-to-source voltage is less than the predetermined threshold and in response to the first logic state and the second logic state, adjusting a switching frequency of the llc resonant converter such that the switching frequency moves back and forth across a boundary of body diode conduction, wherein a frequency difference between the switching frequency and a resonant frequency of the llc resonant converter is less than or equal to one frequency adjustment step.. .

Synchronous rectifier drive and soft switching circuit

A circuit includes a synchronous rectifier that receives an alternating current (ac) voltage from a transformer secondary and provides a rectified direct current (dc) output voltage in response to a control input signal. A secondary rectifier switching circuit generates the control input signal.
Texas Instruments Incorporated

Activation of a synchronous rectifier

A rectifier bridge circuit is described for rectifying the phase voltage generated by a generator, including a positive half-bridge having multiple rectifier elements and a negative half-bridge having multiple rectifier elements. The rectifier elements each have a controllable switch having a diode connected in parallel.

Synchronous rectifier and alternator using the same

A rectifier 107 includes a rectifying mosfet 101 that performs synchronous rectification, a control circuit 106 that inputs a voltage across a pair of a positive-side main terminal tk and a negative-side main terminal ta of the rectifying mosfet 101 to determine an on or off state of the rectifying mosfet 101 based on the inputted voltage, and a capacitor 104 that supplies power to the control circuit 106. The control circuit 106 includes a blocking circuit 105 that inputs the voltage across the pair of main terminals of the rectifying mosfet 101, to block power supply to the control circuit 106 when the inputted voltage across the pair of main terminals is higher than or equal to a first voltage, and to unblock power supply to the control circuit 106 when the inputted voltage across the pair of main terminals is lower than the first voltage..
Hitachi Power Semiconductor Device, Ltd.

Power supply device and a synchronous rectifier pcb

A power supply device includes a main unit and a power switching module. The main unit includes a primary circuit board, a transformer including a primary and a secondary coil, a primary-side circuit and a secondary-side circuit.
Lite-on Electronics (guangzhou) Limited

Synchronous rectifier, use of such a synchronous rectifier in a switching power supply, as well as a switching power supply

synchronous rectifier, which rectifies an alternating voltage signal as an input signal and/or forwards a dc voltage signal as an input signal for use as an output signal, at least comprising:—a rectifying unit composed of at least one controllable switch element; a smoothing unit, which is connected to the rectifying unit and smooths the signal rectified or forwarded by the rectifying unit, in order to provide a smoothed signal for use as output signal; a control logic, which controls the rectifying unit based on the input signal and the output signal coming from the smoothing unit.. .
Endress+hauser Gmbh+co. Kg

Soft transition on all switching elements two transistors forward converter

A method is shown to improve any forward topology operation to achieve efficient resonant transitions by actively shorting the magnetizing inductance and release the short at another time thus producing lower switching losses independent of frequency. In another embodiment of this invention the current from the output inductor is allowed to go negative before the freewheeling synchronous rectifier is turned off, pushing the current back into the primary to create a soft transition across the switching elements before they are turned on.
Rompower Energy Systems, Inc.

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.. .
Silergy Semiconductor Technology (hangzhou) Ltd

Minimum duty cycle control for active snubber

This application provides methods and apparatus for controlling aspects of a synchronous rectifier power converter. In an example, an apparatus can include a minimum duty cycle control circuit configured to receive first control signals for one or more switches associated with the synchronous rectifier power converter, to compare a duty cycle of the first control signals to a minimum duty cycle threshold, and to provide second control signals having at least the minimum duty cycle for an active snubber switch of the synchronous rectifier power converter..
Analog Devices Global

Switching power supply circuit

A switching power supply device includes: a main transformer; a main switch that is connected between a high potential terminal of an input direct current voltage source and a primary-side main winding; a synchronous rectifier circuit includes: a rectifying switch that is connected to a secondary-side main winding in series and that is turned on in synchronization with a turning on state of the main switch and a commutation switch that is connected to the rectifying switch series circuit in parallel and that is turned on in synchronization with a turning off state of the main switch; and an auxiliary switch circuit that turns the commutation switch off. When the main switch stops a switching operation while a voltage exists at a first output terminal on a high potential side, the auxiliary switch circuit turns the commutation switch off to prevent continuation of self-excited oscillation..
Tdk Corporation

Switching power supply circuit

A switching power supply device includes: a transformer; a first switch connected between a high potential terminal of an input dc voltage source and a primary winding; a second switch connected between a low potential terminal of the input dc voltage source and a primary winding; a control circuit outputting a driving pulse signal for synchronizing the first and second switches; first and second rectifying devices; a synchronous rectifier circuit; and a positive bias circuit that applies a positive bias to a control terminal of one of the first and second switches so as to constantly turn the one of the first and second switches on. When the first and second switches stop a switching operation while an output voltage exists between the output terminals, the positive bias circuit applies the positive bias to the one of the first and second switches..
Tdk Corporation

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.
Rohm Co., Ltd.

Buck converter having self-driven bjt synchronous rectifier

A switching converter has a self-driven bipolar junction transistor (bjt) synchronous rectifier. The bjt rectifier includes a bjt and a parallel-connected diode, and has a low forward voltage drop.
Ixys Corporation

Single package synchronous rectifier

A synchronous rectifier comprising a discrete switching device and a controller for controlling the discrete switching device both mounted on a common die pad and packaged in a single package. The packaging of the discrete switching device and the controller together in a single package provides shortest path of connection between the ports of the controller and the switching device, enabling the controller to accurately sense voltage across the switching device thereby avoiding the effect of parasitic inductances and enabling the controller to enable/disable the switching device at the precise time, resulting in improved power consumption and better efficiency..
Alpha And Omega Semiconductor Incorporated

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.
Rohm Co., Ltd.

A control for synchronous rectifiers

The present application relates to the field of switching power supplies and in particular to switching power supplies in which a primary side is isolated from the secondary side and in which a synchronous rectifier on the secondary side is controlled from the primary side. The application provides a method for minimising body diode conduction losses..
Eisergy Limited

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..
Power Integrations Limited

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..
Samsung Electro-mechanics Co., Ltd.

Synchronous rectifier design for wireless power receiver

synchronous rectifier circuit topologies for a wireless power receiver receiving a supply of power from a wireless transmitter are disclosed. The synchronous rectifier circuit topologies include a half-bridge diode-fet transistor rectifier for rectifying the wireless power into power including a dc waveform, using a control scheme that may be provided by a delay-locked loop clock, or phase shifters, or wavelength links to control conduction of fet transistors in the synchronous rectifier circuit topology, and maintaining a constant switching frequency to have the diodes, coupled to fet transistors, to allow current to flow through each one respectively at the appropriate timing, focusing on high conduction times.
Energous Corporation

Method and 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.
Semiconductor Components Industries, Llc

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.
System General Corp.

Adaptive synchronous switching in a resonant converter

An embodiment of a resonant converter includes having resonant circuitry having inductive and capacitive elements configured to create electrical resonance when an input voltage is applied and a synchronous rectifier coupled between at least a portion of the resonant circuitry and an output of the resonant converter. The synchronous rectifier includes a diode, and an electrical switch.
Avogy, Inc.

Adaptive synchronous switching in a resonant converter

An embodiment of a resonant converter includes having resonant circuitry having inductive and capacitive elements configured to create electrical resonance when an input voltage is applied and a synchronous rectifier coupled between at least a portion of the resonant circuitry and an output of the resonant converter. The synchronous rectifier includes a diode, and an electrical switch.
Avogy, Inc.

System and bidirectional wireless power transfer

The present invention relates to a wireless power supply system including a remote device capable of both transmitting and receiving power wirelessly. The remote device includes a self-driven synchronous rectifier.
Access Business Group International Llc

Resonant converter control techniques to manage negative sr current

This disclosure provides control techniques for a resonant converter. In one embodiment, a resonant converter controller includes predictive gate drive circuitry configured to generate a predictive gate drive signal indicative of a time duration from a rising edge of a first drive signal for controlling a conduction state of a first inverter switch of a resonant converter system to a synchronous rectifier (sr) current zero crossing instant of a first sr switch of the resonant converter system, wherein the first tracking signal is based on at least the first drive signal and a voltage drop across the first sr switch.
Fairchild Semiconductor Corporation

Synchronous rectification controller and relative dead-time control method

A synchronous rectification control method suitable for a switching mode power supply with a synchronous rectifier is disclosed. A synchronous rectification controller with a first pin is provided.
Leadtrend Technology Corporation

Synchronous rectification controller and relevant control method

A timing controller provides adaptive timings to control a synchronous rectifier with a body diode. The timing controller has a ramp generator providing a ramp signal at a first capacitor.
Leadtrend Technology Corporation

Predictive and reactive control of secondary side synchronous rectifiers in forward converters

A forward converter has a primary side containing a pwm controller for controlling switching of a power switch and has a secondary side coupled to the primary side via a transformer. The secondary side includes a forward transistor and a catch transistor.
Linear Technology Corporation

System and supplying a synchronous rectifier driver circuit

Methods for supplying a synchronous rectifier (sr) driver circuit and supply voltage generation circuits for a sr driver circuit are described. In one embodiment, a method for supplying a sr driver circuit involves receiving a converted voltage from a secondary winding of a transformer and generating a supply voltage for the sr driver circuit based on the converted voltage, where the supply voltage is higher than an output voltage of the transformer that is generated using the secondary winding.
Nxp B.v.

Power converter having a synchronous rectifier

In an aspect, the present invention provides a high frequency switching power converter. The high frequency switching power converter may include a plurality of soft-switchable power cells flexibly connected to receive an input signal in series and provide an output.
Finsix Corporation

Power converter with modulated secondary-side synchronous rectification

A power converter includes a power transformer, primary-side circuitry connected between a power source and a primary coil, and secondary-side circuitry connected between secondary coil(s) and a load to generate an output voltage and load current for a load. The secondary-side circuitry includes (i) an output inductor, (ii) one or more power transistors, and (iii) control circuitry generating switching signals to operate the power transistors as synchronous rectifiers.
Bel Fuse (macao Commercial Offshore) Limited

Power supplying apparatus

A power supplying apparatus may be capable of switching off a synchronous rectifier on a secondary side in advance by predicting a switching-on time on a primary side. The power supplying apparatus may include: a power converting unit switching power input to the primary side and transferring the power to the secondary side; and a synchronous rectifying unit formed on the secondary side, synchronized with the switching of the power converting unit to perform a rectification switching operation, thereby rectifying the power transferred from the power converting unit, and changing the rectification switching operation before a switching change point of the power converting unit depending on a preset timing..
Samsung Electro-mechanics Co., Ltd.

Synchronous rectifier and a controlling it

A synchronous rectifier comprises at least one rectification switch (102, 103), and a control circuit (104) for controlling the at least one rectification switch to allow unidirectional current flow only. The control circuit comprises at least one current sensor (105, 106) for sensing an alternating component of current of the at least one rectification switch, and at least one driver circuit (107, 108) for controlling the at least one rectification switch at least partly on the basis of the direction of the sensed alternating component.
Efore Oyj

Control of a synchronous rectifier

A method and a control unit for changing a working mode of a synchronous rectifier. The synchronous rectifier comprises at least one controllable switch having a diode in parallell thereof.
Telefonaktiebolaget L M Ericsson (publ)

Inductor current zero-crossing detection method and circuit and switching power supply thereof

In one embodiment, a method of detecting an inductor current zero-crossing in a switching power supply, can include: (i) determining a present output voltage of the switching power supply; (ii) generating a zero-crossing detection threshold voltage according to the output voltage; and (iii) generating a zero-crossing detection signal according to the zero-crossing detection threshold voltage, where the zero-crossing detection signal is used to turn off a synchronous rectifier switch in the switching power supply.. .
Silergy Semiconductor Technology (hangzhou) Ltd

Circuit for driving synchronous rectifier and power supply apparatus including the same

A circuit for driving a synchronous rectifier may include a voltage level detecting unit detecting a voltage level of the synchronous rectifier; an on/off signal generating unit generating an on signal controlling the synchronous rectifier to be turned on when the voltage level detected by the voltage level detecting unit is decreased to a voltage level equal to or less than a preset reference voltage level, and generating an off signal controlling the synchronous rectifier to be turned off when the voltage level detected by the voltage level detecting unit is increased to a voltage level exceeding the reference voltage level; a minimum time determining unit controlling the synchronous rectifier to be turned on during a preset first period; and a blanking time determining unit controlling the synchronous rectifier so as not to be turned on during a preset second period after the synchronous rectifier has been turned off.. .
Samsung Electro-mechanics Co., Ltd.

Buck converter having self-driven bjt synchronous rectifier

A switching converter has a self-driven bipolar junction transistor (bjt) synchronous rectifier. The bjt rectifier includes a bjt and a parallel-connected diode, and has a low forward voltage drop.
Ixys Corporation

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.
Nxp B.v.

Forward converter with self-driven bjt synchronous rectifier

An ac-to-dc converter circuit includes dc-to-dc converter that in turn includes a secondary side circuit. The secondary side circuit includes a secondary winding, a pair of bipolar transistor-based self-driven synchronous rectifiers, a pair of current splitting inductors, and an output capacitor.
Ixys Corporation

Dual-edge tracking synchronous rectifier control techniques for a resonant converter

This disclosure provides control techniques for a resonant converter. In one control technique, for switching speeds that are below the resonant frequency of the primary stage of the converter, the switches of the synchronous rectifier (sr) portion (sr switches) of the resonant converter are controlled based on a rising edge of the corresponding primary side switch and the turn off time of a corresponding sr switch.

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.
Dialog Semiconductor Inc.

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.
Iwatt Inc.

Apparatus and high efficiency llc resonant converters

A method comprises providing a resonant converter, wherein the resonant converter comprises an input switch network coupled to a power source, wherein the input switch network comprises a plurality of power switches, a resonant tank coupled to the plurality of power switches, a transformer coupled to the resonant tank and an output stage coupled to the transformer, wherein the output stage comprises a synchronous rectifier formed by a first switch and a second switch, detecting a drain voltage of the first switch, comparing the drain voltage with a predetermined voltage threshold, wherein the drain voltage is coupled to a negative input of a comparator and the predetermined voltage threshold is coupled to a positive input of the comparator, generating a logic state based upon an output of the comparator and adjusting, by a control circuit, a switching frequency of the resonant converter based upon the logic state.. .
Futurewei Technologies, Inc.

Drive circuit for synchronous rectifier and method thereof

A power converter includes a primary side power circuit, a secondary side power circuit, and a synchronous rectifier drive circuit. The primary side power circuit includes a primary winding and a main switch coupled in series.
General Electric Company

Synchronous rectifier control circuit and synchronous

A synchronous rectifier control circuit an includes a current transformer (ct), a bridge rectifier, and a comparator, where the ct is connected in series to a secondary side, performs sampling on a loop current of the secondary side to obtain a current detection signal, and outputs the obtained current detection signal to the bridge rectifier; the bridge rectifier acquires a secondary-side sampling current according to the current detection signal, and outputs the secondary-side sampling current to the comparator so that the comparator generates a voltage difference; and an output signal of the comparator turns over so as to control on and off of a synchronous rectifier transistor. In this way, high-speed and high-precision control over a synchronous rectifier transistor can be implemented.
Huawei Technologies Co., Ltd.

Automatic timing adjustment for synchronous rectifier circuit

A circuit includes a conduction detector configured to monitor conduction of a body diode of a synchronous rectifier switch relative to a predetermined threshold and to generate a detector output that indicates conduction or non-conduction of the body diode. A window analyzer is configured to generate a timing signal to indicate if the synchronous rectifier switch is turned off prematurely or turned off late relative to an on-time turn off based on the detector output from the conduction detector.
Texas Instruments Incorporated

Commutation current steering method in a zero volt switching power converter using a synchronous rectifier

A commutation current steering method is provided for a power converter having an isolation transformer, a plurality of primary zvs switches, a plurality of secondary switches for synchronous rectification, and a boosting resonant circuit. A commutation current is shared between all of the switches, and a resonance is induced in the boosting resonant circuit by controlling each of the synchronous rectifier switches to turn off at a time prior to a turn-off time for a corresponding one of the switches operating under zvs conditions, wherein the primary current is boosted above a minimum commutation value during zvs periods.
Power-one, Inc.

Self-driven ac-dc synchronous rectifier for power applications

Systems, methods, and devices that employ self-driven gate-drive circuitry to facilitate controlling power switches to emulate a diode bridge to synchronously rectify a power signal are presented. A single-phase or multi-phase synchronous rectifier can comprise at least a first pair of switches of a first conducting path and a second pair of switches of a second conducting path that can form or emulate a diode bridge.
City University Of Hong Kong

Dc-dc converter device

A dc-dc converter device and method for controlling the dc-dc converter device includes controlling gate drivers connected to the respective gate of first and second resonant circuit switches of a resonant circuit, controlling gate drivers connected to the respective gate of first and second rectifier switches of a synchronous rectifier, and detecting whether a shutdown criteria is fulfilled or not. If the shutdown criteria is fulfilled, the method is further includes the step of sending a shutdown signal to a shutdown device..
Eltek As

Synchronous rectifier control circuits of power converters

A synchronous rectifying control circuit of a power converter is provided. The synchronous rectifying control circuit comprises a synchronous rectifying driver, a charge pump capacitor, and a capacitor.
System General Corporation

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.
System General Corp.

Apparatus and wireless power reception

An apparatus and a method for wireless power reception include converting a received wireless power to a wireless power for charging using a synchronous rectifier and a direct current/direct current (dc/dc) converter having a structure providing a high efficiency and low heat generation even when a high charging current is supplied.. .
Samsung Electronics Co., Ltd.

Synchronous rectifier control for a double-ended isolated power converter

An apparatus comprises a power converter circuit and a control circuit. The power converter circuit includes a primary circuit side and a secondary circuit side.
Analog Devices Technology

Control circuit for a synchronous rectification circuit, llc resonant converter and associated method

A control circuit for a synchronous rectification circuit, a llc resonant converter and a control method. The control circuit has a first comparing circuit, a second comparing circuit, a blanking circuit, a first logic circuit and a second logic circuit.
Chengdu Monolithic Power Systems Co., Ltd.

Magnetic integration double-ended converter

A magnetic integration double-ended converter with an integrated function of a transformer and an inductor includes an integrated magnetic member having a magnetic core with three magnetic columns having at least three windings (np, ns1, ns2) and at least one energy storage air gap, where a primary winding (np) and a first secondary winding (ns1) are both wound around a first magnetic column or are both wound around a second magnetic column and a third magnetic column, and a second secondary winding (ns2) is wound around the second magnetic column; an inverter circuit with double ends symmetrically working, acting on the primary winding (np); and a group of synchronous rectifiers (sr1, sr2), gate electrode driving signals of which and gate electrode driving signals of a group of power switch diodes (s1, s2) of the inverter circuit with the double ends symmetrically working complement each other.. .

Optimal ripple injection for a boost regulator

A boost switching regulator incorporates a ripple injection circuit to generate a voltage ripple signal for feedback control that mimics the actual ripple signal of the regulated output voltage. In this manner, the ripple injection circuit achieves optimal ripple injection for stable and enhanced feedback control.

Synchronous rectification in the three-level inverter-converter topologies

A power module for a three-level power inverter/converter that employs synchronous rectification for use in a uni-directional active rectifier mode to reduce static losses and enhance efficiency across the circuit. Each synchronous rectifier can be a silicon carbide (sic) power mosfet connected in parallel with a sic power diode, for example..

Synchronous rectification controlling circuit and synchronous rectification controlling method

In one embodiment, a synchronous rectification circuit can include: (i) a sampling circuit configured to sample a voltage across first and second power terminals of a synchronous rectifier, and to generate a first sampling voltage; (ii) an enable controlling circuit configured to delay the first sampling voltage, and to generate a second sampling voltage, and to activate a ramp voltage when the first sampling voltage is higher than the second sampling voltage; (iii) the enable controlling circuit being configured to generate an enable controlling signal in response to a comparison of the ramp voltage against a reference voltage that represents a predetermined light load condition; and (iv) a driving circuit configured to activate a driving signal to turn on the synchronous rectifier when the enable controlling signal and a synchronous rectification open signal are active.. .

Activation activating a direct voltage converter

The invention relates to an activation apparatus (20) for a galvanically decoupled direct voltage converter having a synchronous rectifier, comprising a signal generating device (22), which is designed to generate control signals (22c, 22d) for switch devices of the synchronous rectifier and a reference current signal (22b), a first comparator device (23), which is coupled to the signal generating device (22), and which is designed to detect the secondary-side output current (jo) of the synchronous rectifier, compare it to the reference current signal (22b) and generate a current control signal in dependence on the comparison, and a pulse width modulation device (25), which is coupled to the signal generating device (22) and the first comparator device (23) and which is designed to generate pulse width modulated activation signals (25a) for the switch devices of the synchronous rectifier on the basis of the control signals (22c, 22d) and the current control signal, wherein the signal generating device (22) is furthermore designed to reduce the reference current signal (22b) within a first predetermined timespan to a predetermined reference current threshold.. .

Synchronous rectifier

The invention relates to a synchronous rectifier (16) for integration into a power source (10) in order to provide a direct current, in particular in a cube or ashlar-shaped unit of a heavy-current transformer (12), comprising circuit elements (24), an actuation circuit (17) for actuating the circuit elements (24) and a supply circuit (48), wherein a printed circuit board (35) with conductor tracks and connection surfaces is provided for receiving electronic components. For reduction of losses and improvement of efficiency, the circuit elements (24), the actuation circuit (17) and the supply circuit (48) are arranged on the circuit board (35) for the autonomous operation thereof, wherein several openings (37), which are arranged in parallel and in series, are provided on the circuit board (35) for receiving protrusions (36) of a contact plate (29), above which openings (37) the circuit elements (24) are arranged and are connected or soldered and can be contacted with the protrusions (36) of the contact plate (29)..

Resistance welding device comprising a power source arranged on a welding gun

The invention relates to a resistance welding device (1) comprising a power source (10) in order to provide a welding current for welding workpieces (2, 3), a welding gun (4) with two gun arms (5) comprising one electrode (7) each in order to impress the welding current into the workpieces (2, 3), wherein the power source (10) comprises a heavy-current transformer (12) with at least one primary winding (13) and at least one secondary winding (14) with center tapping, a synchronous rectifier (16) connected with the at least one secondary winding (14) of the heavy-current transformer (12) and comprising circuit elements (24), and a circuit (17) for actuating the circuit elements (24) of the synchronous rectifier (16). For reduction of losses and improvement of efficiency, the power source (10) is arranged at the welding gun (4) and the power source (10) comprises at least four contacts (20, 21, 22, 23) to form a multi-point contacting, wherein two first contacts (20, 21) of one polarity are connected to the one gun arm (5) and two additional contacts (22, 23) of opposite polarity are connected to the other gun arm (5)..

Power source and cooling such a power source

The invention relates to a power source (10) for providing a direct current, comprising a heavy-current transformer (12) with at least one primary winding (13) and at least one secondary winding (14) with center tapping, a synchronous rectifier (16) connected with the at least one secondary winding (14) of the heavy-current transformer (12) and comprising circuit elements (24), and a circuit (17) for actuating the circuit elements (24) of the synchronous rectifier (16), and a supply circuit (48) for supplying the synchronous rectifier (16) and the actuation circuit (17), and to a method for cooling such a power source (10). For reduction of losses and improvement of efficiency, the synchronous rectifier (16) and the actuation circuit (17) and the supply circuit (48) thereof are integrated in the heavy-current transformer (12)..

Power converter with self-driven synchronous rectifier control circuitry

An ac-dc power converter is provided with two pairs of self-driven synchronous rectifier switches in addition to, or in place of, diode bridge rectifiers for boosting efficiency and reducing cost. An ac sensing circuit is coupled to ac input terminals, and a dc level shifting circuit applies a dc offset to an ac input signal received via the sensing circuit.

Power supply method and apparatus

A method and apparatus for providing a power supply for an amplifier is provided. The power conversion is achieved using synchronous rectifiers in a regulated half bridge power supply, taking the sum of the positive and negative rails as feedback, in order facilitate energy transfer between positive and negative output rails.

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.

Method of controlling synchronous rectifier for power converter, control circuit, and power converter thereof

A method for controlling a synchronous rectifier for a power converter, a control circuit, and a power converter thereof are provided. The method comprises the following steps: turning on a transistor by a rectifier; generating a switching-period signal in accordance with a period of a voltage-sensing signal; generating a turn-on-period signal in accordance with a turned-on period of the rectifier; generating a first disabling signal responding to the switching-period signal; and generating a second disabling signal in response to the turn-on-period signal.

Reverse current control for an isolated power supply having synchronous rectifiers

In certain example embodiments, a system is provided that includes a circuit. The system also includes a reverse current control module that provides an isolated power supply in order to protect one or more devices in a power chain during one or more testing activities having one or more requirements..

System and 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.

Power conditioning circuit to maximize power delivered by a non-linear generator

A circuit receives variable voltage and current from a renewable power source and optimally loads the source to maximize power delivered into a dc bus having constant voltage. A boost circuit and synchronous rectifier having a controlled duty cycle step up the voltage from the renewable source.

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..

Method of forming a synchronous rectifier controller and structure therefor

In one embodiment, a synchronous rectifier controller is configured to initiate forming an off-time interval for a first period of time responsively to the controller forming a disable state of a switching signal wherein the control circuit maintains the switching signal in the disable state for at least the off-time interval. The controller is also configured to restart forming the off-time interval responsively to a voltage of a synchronous rectifier becoming a first value prior to expiration of the first period of time..

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.

Control circuit for switching power converters with synchronous rectifiers

A control circuit for switching power converters with synchronous rectifiers is disclosed for providing start-up and shut-down protection. The control circuit for switching power converters with synchronous rectifiers includes a means for blocking the driving signals to the synchronous rectifiers, a voltage sampling circuit, a reference voltage, and a comparator.

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.

Blanking control circuit for controlling synchronous rectifier and controlling synchronous rectifier using the circuit

Disclosed herein are a blanking control circuit for controlling a synchronous rectifier and a method of controlling the synchronous rectifier by using the blanking control circuit. The blanking control circuit for controlling a synchronous rectifier includes: a power generating unit that receives power from the outside to generate a reference voltage and a bias current that are used in an integrated circuit (ic); a driving unit that receives the reference voltage and the bias current generated by using the power generating unit to generate a voltage for driving a switch of the synchronous rectifier; and a load sensing unit that determines a state of a load by sensing an output voltage of the synchronous rectifier driven by the driving unit, and generates a corresponding signal if the state of the load is in a low load state so as to turn off the switch of the synchronous rectifier..

Adaptive dead time control scheme for switch mode power converter with synchronous rectifiers topology

An adaptive dead time (adt) control scheme for use with a switch mode power converter having a full bridge with synchronous rectifiers topology. A controller which implements the control scheme includes an input circuit arranged to receive a signal representative of the converter's output voltage, and an output circuit arranged to operate the converter's switching elements and synchronous rectifiers to produce a desired output voltage.

Snubber circuit for dc-dc voltage converter

The invention relates to a dc-dc voltage converter (1), having a transformer (2) having a primary winding (2a) and a secondary winding (2b, 2c) having a centre tap, an output inductor (3), which is connected to the centre tap and to a first output connection (9a), a synchronous rectifier circuit (4) having two synchronous rectifier switches (14a, 14b), each of which is connected to the terminal taps of the secondary winding (2b, 2c), and which are designed to produce a rectified output voltage on a second output connection (9b), and a snubber circuit (5) that is switched by means of the synchronous rectifier circuit (4). In this case, the snubber circuit has two diodes (16a, 16b), each of which is coupled to the terminal taps of the secondary winding (2b, 2c), a capacitor (6), which is coupled to the two diodes (16a, 16b) and which is designed to store resonant oscillation energy arising in the synchronous rectifier circuit (4), and a discharge circuit (7) comprising a series circuit containing a discharge switch (18) and a resistor (17), wherein the discharge circuit (7) is coupled between the first output connection (9a) and the capacitor and is designed to selectively feed back stored charge in the capacitor (6) to the first output connection (9a)..

Power converting device and synchronous rectifier control circuit

A power converting device includes a main switch, a synchronous rectifier switch, a rectifier-filter circuit which outputs an output voltage, and a synchronous rectifier control circuit which includes a sampling circuit coupled to the rectifier-filter circuit for outputting a voltage variation signal, a differential amplifier circuit that outputs an amplified signal by adding the output voltage and an offset voltage to the voltage variation signal attenuated thereby, and a comparison circuit that compares the amplified signal with the output voltage so as to output a trigger signal, such that the synchronous rectifier switch is turned on when the main switch is turned off, and is turned off prior to conduction of the main switch.. .

Synchronous rectifier circuit

Provided is a synchronous rectifier circuit which, even if a synchronous rectification element having a low on-resistance is used, can perform a synchronous rectifying operation without being influenced by the inductance component. It is a synchronous rectifier circuit having a synchronous rectification element qsr1 and a synchronous rectification control circuit ic1 for turning on/off the synchronous rectification element qsr1 in accordance with the current isr flowing through the synchronous rectification element qsr1, including a current detection circuit for detecting the current isr flowing through the synchronous rectification element qsr1 during an on-period of the synchronous rectification element qsr1 as a synchronized voltage waveform, the synchronous rectification control circuit ic1 being configured so as to turn off the synchronous rectification element qsr1 on the basis of the voltage waveform detected by the current detection circuit 1a..

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..

Power converting device

A power converting device includes a transformer, a first switch coupled to a primary winding of the transformer, a pwm controller which generates a first pwm signal for controlling conduction and non-conduction of the first switch and which generates a control signal that leads the first pwm signal, a rectifier-filter circuit which rectifies an induced voltage generated by a secondary winding of the transformer, a second switch coupled to the secondary winding, and a synchronous rectifier controller which controls conduction and non-conduction of the second switch, and which controls, according to the control signal, the second switch to become non-conductive prior to conduction of the first switch.. .

Synchronous rectifier controller, power converter using same, and method therefor

In one form, a synchronous rectifier controller includes a drive clamp adjust terminal, a drive terminal, a clamp voltage generator circuit coupled to the drive clamp adjust terminal for measuring a signal at the drive clamp adjust terminal and providing a clamp voltage having a value determined by the signal, and a driver for providing a drive signal to the drive terminal at a voltage related to the clamp voltage during an active period of the drive signal. In an alternate form a power converter includes a rectifier transistor having a first current electrode, a control electrode for receiving a drive signal, and a second current electrode, and a synchronous rectifier controller having a first terminal coupled to the control electrode of the rectifier transistor for providing the drive signal alternately in an active state and an inactive state..

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..

Synchronous rectifier control techniques for a resonant converter

A resonant converter system includes a first stage having inverter circuitry and resonant tank circuitry configured to generate an ac signal from a dc input signal, a transformer configured to transform the ac signal, and a second stage. The second stage features synchronous rectifier (sr) circuitry including a plurality of sr switches each having a body diode and sr control circuitry.

Synchronous dc-dc conversion

A synchronous dc-dc converter (300) for converting an input voltage (vin) into an output voltage (vout), the converter having a continuous current operative mode (ccm) and a discontinuous current operative mode (dcm), the converter including: an active switch (302) receiving a first gate signal for turning on the active switch for a first time interval (tq1), the first gate signal having a period (tprd); a synchronous rectifier (304) receiving a second gate signal for turning on the synchronous rectifier for a second time interval (tq2); and a controller (306) for determining an estimation (tq1est) for the first time interval, and thereafter comparing the estimation (tq1est) with the value of the first time interval (tq1); wherein responsive to the comparison the controller (306) determines an operative mode of the converter (300) and controls the second time interval (tq2) depending on the determined operative mode.. .

Synchronous rectifying apparatus and controlling method thereof

The present application provides a synchronous rectifying apparatus and a control method thereof, the apparatus comprising: a transformer, a primary circuit, a rectifying circuit, a self-driving circuit, a pwm control circuit and an auxiliary control module including at least one auxiliary control circuit and at least one auxiliary winding, wherein the auxiliary control circuit includes at least one auxiliary switch and is electrically coupled to the pulse width modulation control circuit and the auxiliary winding via the auxiliary switch, and the auxiliary winding is electrically coupled to the transformer; wherein before the transfer switch of the primary circuit is controlled to be turned on by the switching control signal, the auxiliary switch is controlled to be turned on by the auxiliary control signal, and the synchronous rectifier of the rectifying circuit is controlled to be turned off through the self-driving signal.. .

Process for interconnection of electronic power modules of a rotary electrical machine, and assembly of interconnected power modules obtained by means of this process

A method for interconnecting electronic power modules of a polyphase rotary electric machine. The power modules are disposed in open cavities of a heat sink and comprise substrates on which are provided mosfets of a synchronous rectifier bridge and integrated control circuits.

Switching power source device

A synchronous rectification switching power source device accurately determines the timing of the turning off of a synchronous rectifier switching element regardless of the state of the load, and a synchronous rectification period is utilized to the maximum. The switching power source device is configured of a main fet connected to a primary winding of a transformer, a snubber circuit connected to the primary winding, a synchronous rectifier fet connected to a secondary winding of the transformer, a diode connected to the synchronous rectifier fet, a synchronous rectifier fet drain voltage detection unit, an output voltage detection unit, and a drive control unit.

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.. .



Synchronous Rectifier topics:
  • Synchronous Rectifier
  • Synchronous
  • Flyback Converter
  • Feedback Signal
  • Modulation
  • Pulse Width Modulation
  • Active Clamp
  • Circuit Board
  • Low Frequency
  • Sleep Mode
  • Duty Cycle
  • Differential Amplifier
  • Integrated Circuit
  • Bipolar Transistor
  • Distributed


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