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Synchronous Rectifier patents

      

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

Wireless power receiver with a synchronous rectifier
embodiments disclosed herein describe a wireless power receiver including a synchronous rectifier using a class-e or a class-f amplifier. The voltage waveform generated from a power source, for example an antenna, is tapped to create a feed-forward tap-line to provide a gate voltage to the transistor of the class-e or the class-f amplifier.
Energous Corporation


Resonant rectifier circuit with capacitor sensing
a wireless power transfer system using a resonant rectifier circuit with capacitor sensing. A wireless power transfer system includes a power receiver resonant circuit and a synchronous rectifier.
Texas Instruments Incorporated


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.
Semiconductor Components Industries, Llc


Efficient power supply voltage regulation for synchronous rectifier controller
a flyback converter is provided with a synchronous rectifier (sr) controller including a pulse linear regulator (plr) charging path and an ldo charging path. The sr controller is configured to monitor the switching period and/or duty cycle of a power switch in the flyback converter to select between the plr and ldo charging paths..
Dialog Semiconductor Inc.


Method and synchronous rectifier
a synchronous rectifier controller includes an exception timer, one or more blanking timers, and control logic. The control logic may detect a beginning of a conduction phase using a current sense signal.
Semiconductor Components Industries, Llc


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


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.
Semiconductor Components Industries, Llc


Communication circuit for flyback power converter with synchronous rectifier
a method for communicating with a power converter comprises initiating a communication sequence by sensing a first distortion of a sensed waveform during a discharge period of a first power transfer cycle of the power converter. The sensed waveform is proportional to a secondary current of the power converter.
Semiconductor Components Industries, Llc


Dynamic sharing average current mode control for active-reset and self-driven synchronous rectification for power converters
a circuit for providing dynamic output current sharing using average current mode control for active-reset and self-driven synchronous rectification with pre-bias startup and redundancy capabilities for power converters. The circuit communicates a secondary side feedback signal to a primary side via a bidirectional magnetic communicator that also provides a secondary voltage supply.
Crane Electronics, Inc.


System for synchronous rectifier voltage regulator shoot-through detection
a method, circuit, and information handling system detect an assertion of a low side gate driver signal of a low side gate driver coupled to a low side gate of a low side selectively conductive device, to obtain a reference voltage value, to detect a local high side positive supply voltage at a high side positive supply voltage terminal of a high side selectively conductive device, to compare the local high side positive supply voltage to the reference voltage value to provide an indication of a cross-conduction detection, and to provide a warning of the cross-conduction detection before occurrence of a failure of a selectively conductive device selected from a group consisting of the low side selectively conductive device and the high side selectively conductive device.. .
Dell Products, Lp


Switching control circuit with signal process to accommodate the synchronous rectifier of power converters

a switching control circuit of a power converter according to the present invention comprises an input circuit and a clock generator. The input circuit is coupled to receive a feedback signal for generating a switching signal.
Semiconductor Components Industries, Llc

Synchronous 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

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

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

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

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

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

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

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

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

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.

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.
Klemm+sohn Gmbh & Co. Kg

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

. .

Nxp B.v.

. .

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