134 results about "Synchronous rectifier" patented technology

The invention belongs to the technical field of planar transformers, and relates to a fractional-turn planar transformer of a matrix type integrated structure and a converter. Comprising M magnetic cores and a PCB (printed circuit board), and each magnetic core is provided with a plurality of layers of primary windings and N sections of secondary windings; a circuit structure is arranged between the secondary winding on the first surface and the secondary winding on the second surface, and a source electrode of a synchronous rectifier tube in the circuit structure is connected with a grounding end of an output capacitor; positive potential ends, back to two output capacitors in the circuit structure, on the first surface and the second surface are connected; according to the planar transformer, the advantages of the fractional turn scheme and the matrix scheme of the existing planar transformer are combined, the defects of the fractional turn scheme and the matrix scheme are suppressed, and the requirements of the market for the high-transformation-ratio transformer on the higher server power supply bus voltage are met.

A battery pack charger having housing including a battery pack interface for removably receiving a battery pack and a power input. The battery pack charger including a hybrid flyback converter having a primary side including a DC-DC half-bridge and a secondary side including a synchronous rectifier. The hybrid flyback converter is electrically connected between the power input and the battery pack interface and is configured to provide charging power from the power input to the battery pack interface.

This disclosure presents an embodiment of a power supply device for a submarine data center. One specific embodiment of the power supply device includes a pre-stage voltage regulator / conversion component, a post-stage DC-DC converter component, and a combined protection circuit. The pre-stage voltage regulator / conversion component includes several parallel single-group voltage regulator branches, each branch connected in series with a varistor and a color-coded resistor. A thin-film capacitor is connected in parallel to the output terminal of the pre-stage voltage regulator / conversion component. The post-stage DC-DC converter component, electrically connected to the pre-stage voltage regulator / conversion component, includes at least two sets of full-bridge DC synchronous rectifier circuits. The combined protection circuit includes a pre-stage combined protection circuit, a post-stage active voltage clamping circuit connected in parallel to the output side of the post-stage DC-DC converter component, and a rectifier diode bridge connected between the constant current input port and the pre-stage voltage regulator / conversion component. The pre-stage combined protection circuit is connected in series to the input side of the rectifier diode bridge. By connecting multiple voltage regulator branches in parallel and combining them with the combined protection circuit, ripple is reduced. This embodiment can improve the power supply stability of the power supply device.

A power converter can include: M transformer units, each including primary and secondary windings; M bridge arms, each being is coupled between two input terminals of the power converter to receive a DC input voltage, and each bridge arm comprises a high-side switch, a low-side switch, and a synchronous rectifier coupled in series; where a first terminal of each of the primary windings is coupled to a common node between the high-side switch and the low-side switch in one of the M bridge arms, and a second terminal of each primary winding is coupled together; and where one terminal of each of the secondary windings is coupled to a common node between the low-side switch and the synchronous rectifier in one of the M bridge arms, and the other terminal of each of the secondary windings is coupled to a first output terminal of the power converter.

A secondary side controller for an AC-DC converter, the secondary side controller having a single synchronous rectifier sense (SR_SNS) terminal coupled to a synchronous rectifier (SR) of the AC-DC converter, and a voltage divider circuit coupled to the single SR_SNS terminal, the voltage divider circuit configured to provide a signal to a sense circuit. The voltage divider includes an active diode, an internal resistive element, and a switch, wherein the active diode is configured to control the switch to enable or disable the internal resistive element based on a comparison of a voltage at the single SR_SNS terminal to a reference voltage.

The application relates to a critical conduction mode control method of a totem-pole PFC converter, which utilizes energy equivalence to determine the resonance process of inductor current at switching commutation, carries out totem-pole Boost inductor current value estimation, and on this basis, utilizes a current zero-crossing point prediction algorithm to calculate the turn-on and turn-off time to generate corresponding active tube-synchronous rectifier tube commutation dead time T d,f , synchronous rectification conduction time T SR , rectifier tube-active tube commutation dead time T d,r ; the PWM drive signals of high-speed switching tubes Q1 and Q2 are generated by T on , T d,f , T SR , T d,r ; the power frequency drive signals of low-speed switching tubes Q3 and Q4 are generated by comparing the input alternating voltage v ac with a hysteresis comparison loop and 0. The method can effectively get rid of the dependence on a current zero-crossing detection circuit and a current sensor, reduces the cost and improves the system stability.

The application belongs to the technical field of digital signal processing, and particularly discloses a digital signal generation and processing method and system for synchronous rectification, wherein the method comprises the following steps: obtaining the staggered sampling code stream of a synchronous rectification device, and outputting time-aligned voltage and current characteristic values after group delay hard compensation; performing polynomial thermodynamic school correction in combination with discrete shell temperature sampling values; performing physical safety working area boundary checking on the corrected characteristic values, addressing and interpolating output of the target optimal conduction timing value in the irregular lattice space; extracting a feature vector to perform recursive least square prediction, and outputting an overshoot prediction extreme value; performing discrete charge integration in combination with a nonlinear capacitance function, and iteratively outputting a target dead time value based on the charge conservation criterion; and the application has the advantages of accurate control timing, physical boundary safety and dead time self-adaptation.

This application provides a multi-output flyback converter and power supply system, relating to the field of power supply technology. The multi-output flyback converter includes a control module, a transformer, a primary-side switching module, and multiple synchronous rectifier modules. The primary-side switching module is connected to the primary winding of the transformer, and each synchronous rectifier module is connected to each secondary winding of the transformer. Each synchronous rectifier module includes two back-to-back connected switching transistors. The control module is connected to the control terminals of the primary-side switching module, the control terminals of the two switching transistors in each synchronous rectifier module, and the output terminal of each synchronous rectifier module. The control module is used to adjust the duty cycle of the primary-side switching module according to the actual output voltage of the actively regulated output path; and to adjust the duty cycle of the switching transistors in each non-actively regulated output path according to the actual output voltage of each non-actively regulated output path, thereby eliminating cross-regulation between the outputs.

The present invention discloses a two-output charging circuit and a method for controlling its auxiliary circuit switch. The two-output charging circuit includes two first-stage switch transistors in the half-bridge inverter circuit generating dead time at changing-over and turn-on, and the second-stage switch transistor being turned off within the dead time. In the present invention, making use of a magnetic core to return from the reverse in its bidirectional magnetization process generates dead time, and controlling the time sequence of the switch device of the post-circuit in the dead time abates the voltage stress of the synchronous rectifier diode and reduces the loss of the absorption circuit of the synchronous rectifier circuit.

A power converter includes a controller for controlling a synchronous rectifier (SR) switch. The controller includes a request control circuit and a discharge prevention circuit. The request control circuit is configured to generate a request signal in response to the output of the power converter. The request control circuit generates a secondary control signal to control the SR switch. The discharge prevention circuit is configured to prevent the discharge of parasitic capacitance of the power switch caused by the activating of the SR switch. The discharge prevention circuit further generates a prevention signal to: disable the control of the synchronous rectifier switch by the secondary control signal when the period of the request signal is greater than a first time threshold; and enable the control of the synchronous rectifier switch by the secondary control signal when the period of the request signal is less than a second time threshold.

The invention discloses a multi-output switching power supply and a control method thereof. A first output loop in the multi-output switching power supply comprises a first synchronous rectifier tube and a first output switching tube; a first feedback signal is obtained according to the output feedback signal of the first output loop, and a second feedback signal is obtained according to the output feedback signal of at least one of the other output loops; a zero-voltage conduction pulse signal is generated according to the second feedback signal to conduct a first synchronous rectifier tube, so that a negative current is generated on a main power tube in the input loop; a first output control signal synchronous with a zero voltage conduction pulse signal is generated according to the first feedback signal and the zero voltage conduction pulse signal so as to control the on-off state of the first output switch tube; according to the invention, the synchronization between the first output switch tube and the main power tube can be realized without adopting a complex synchronization signal generation circuit, the control is simple, and the cost is low.

To provide safety circuits that decrease the likelihood of an electric shock caused by a high current source and a high voltage source.SOLUTION: A magnetic inductive resonance charging circuit includes: a resonant network 101 having an inductive secondary coil 104 that converts a magnetic field received from an inductive primary coil into an alternating current (AC) signal; and a synchronous rectifier that rectifies the AC signal to generate a direct current (DC) signal for application to a load. The synchronous rectifier includes a variety of configurations for shunting the AC waveform of an AC current source in the event of a fault. For example, a rectifier controller 115 may hold a pair of normally open switches 107, 108 of the synchronous rectifier off and a pair of normally closed switches 109, 110 of the synchronous rectifier on to shunt the AC current source when an over-voltage, over-current fault condition in a current and voltage sensor 113 or an over-temperature fault condition in a temperature sensor 117 is detected. The capacitive electromagnetic interference produced in the chassis of an electric vehicle is grounded when the resonant network is unbalanced.SELECTED DRAWING: Figure 1

This invention proposes a synchronous rectification controller suitable for power conversion circuits. The synchronous rectification controller includes a first terminal, a second terminal, and a switch detection unit. The first terminal is coupled to the primary side of the power conversion circuit. The second terminal is coupled to the secondary side of the power conversion circuit. The switch detection unit, coupled to the first terminal, detects the switching of the primary side of the power conversion circuit. When the switch detection unit detects a trigger signal, it drives the second terminal to send a synchronization signal, thereby controlling the secondary side of the power conversion circuit.

This invention provides a flyback power supply, a synchronous rectification control circuit, and a method, comprising: a turn-on control module for generating a turn-on control signal for the synchronous rectifier; a turn-off control module for generating a turn-off control signal for the synchronous rectifier when the drain-source voltage of the synchronous rectifier rises to a turn-off threshold, and simultaneously adjusting the turn-off threshold based on the peak value of the drain-source voltage of the synchronous rectifier; and a drive signal generation module for generating a drive signal for the synchronous rectifier based on the turn-on control signal and the turn-off control signal; wherein the turn-off threshold is a negative value. This invention automatically adjusts the turn-off threshold according to the drain-source voltage of the synchronous rectifier, solving the voltage stress problem caused by common operation in continuous mode, enabling the system to operate safely and efficiently in continuous mode; simultaneously, it achieves maximum conduction time in discontinuous mode, resulting in high system efficiency; furthermore, this invention reduces the comparator delay requirement and eliminates the need for specific processing of the primary-side control drive, making it simple and easy to implement.

The application discloses an isolated single-stage DC-DC converter based on an integrated matrix magnetic core. The integrated matrix magnetic core is connected with an input end through a phase-shift full-bridge structure, and the phase-shift full-bridge structure is used for realizing zero-voltage turn-on of a primary side switch tube. The integrated matrix magnetic core is connected with an output end through a current doubling rectifier circuit with a resonance capacitor, and zero-current turn-off and zero-voltage turn-on of a synchronous rectifier tube are realized through resonance. The application realizes zero-voltage turn-on of the primary side switch tube, zero-voltage turn-on and zero-current turn-off of a secondary side synchronous rectifier tube, and improves energy conversion efficiency.

The invention discloses a synchronous rectification leading edge blanking self-adaptive adjustment method adaptive to double-transistor flyback. The method comprises the following steps: detecting the turn-on time of a driving signal of a synchronous rectification controller and the high level time of a high-voltage detection signal; calculating a first duty ratio and a second duty ratio; judging whether a leading edge blanking time self-adaptive adjustment closed-loop condition is met or not; when the turn-on time of the driving signal is increased and is close to the high level time of the high-voltage detection signal, adjusting is stopped, and the current leading edge blanking time is maintained; and if the turn-on time of the driving signal is not increased to be greater than the leading-edge blanking time after the leading-edge blanking time is adjusted by the synchronous rectifier within the preset time range, the leading-edge blanking time is traced back to a default value. According to the method, the leading edge blanking algorithm is optimized in the synchronous rectification controller, so that the change of system power parameters is avoided to the greatest extent, the design complexity of a power supply system is reduced, and the risks of efficiency reduction and temperature rise and heating caused by repeated design and mistaken starting of the system are avoided.

The invention relates to a shutdown protection circuit and a synchronous rectification circuit, and belongs to the technical field of power supply modules, and the shutdown protection circuit comprises a resistor R5, a resistor R6, a capacitor C4, a diode D3 and an MOS tube Q3; the positive electrode of the diode D3 serves as an IN1 end to receive a PWM signal, the negative electrode of the diode D3 is electrically connected with the grid electrode of the MOS tube Q3 through the resistor R6, the source electrode of the MOS tube Q3 is grounded, and the drain electrode of the MOS tube Q3 serves as an output end; and the grid electrode of the MOS tube Q3 is grounded through a parallel combination of a capacitor C4 and a resistor R6. The synchronous rectifier tube can be turned off in time when the power supply is turned off, and negative voltage at the output end is prevented.

This utility model relates to the field of power supply technology, specifically to a synchronous rectification and commutation power supply. It includes a housing, inside which a battery is fixedly installed, with two electrode plates connected to the battery. It also includes a lap plate fixedly installed inside the housing and positioned inside the electrode plates. Furthermore, it includes an adjusting component movably connected to the housing, capable of moving up and down within the housing. Two frames are fixedly installed on the adjusting component, with metal plates movably connected inside the frames. Additionally, it includes two metal sheets laid on the inner wall of the housing, and two lap plates also disposed on the inner wall. Through the adjusting component and metal plates, a simple and rapid commutation operation can be achieved under the drive of a hydraulic cylinder. Furthermore, by using through slots and magnetic switches on the lap plates, and employing methods such as increased creepage clearance and power-off, arcing during commutation is avoided, improving the safety of the power supply.

This document describes techniques for avoiding spurious negative sensing (NSN) detection in flyback AC-DC converters. In an exemplary embodiment, the secondary-side controller of the AC-DC converter includes a frequency detector, a negative sensing detector, and a control logic unit. The frequency detector is configured to determine the frequency of an input signal from the drain node of a synchronous rectifier (SR) circuit on the secondary side of the AC-DC converter. The negative sensing detector is configured to determine a negative voltage of the input signal. The control logic unit is configured to: enable the negative sensing detector when the frequency of the input signal rises above a frequency threshold; and turn on the SR circuit to transfer power to the secondary side of the AC-DC converter when the negative voltage of the input signal falls below a voltage threshold.

This invention relates to the field of switching power supply and detection circuit technology, specifically to a detection circuit and method for detecting the operating status of a synchronous rectifier-encapsulated chip. The circuit includes: a main circuit comprising a main switching transistor and a freewheeling unit, wherein the freewheeling unit is composed of multiple synchronous rectifier-encapsulated chips connected in series, with its tail end connected to the source of the main switching transistor at a common switching node, and its head end grounded; and a status monitoring circuit comprising a conduction voltage drop sampling branch and a status monitoring signal conversion branch, both connected via an optocoupler. The input of the sampling branch is connected to the switching node, and the output, after optocoupler conversion, is output as a detection voltage by the signal conversion branch. This invention solves the problem of difficulty in detecting the conduction state of a synchronous rectifier-encapsulated chip when the gate is not brought out. By utilizing the characteristics of optocouplers, it achieves the signal detection function for the weak negative voltage drop during the conduction period of the synchronous rectifier-encapsulated chip, providing an accurate and non-invasive means of discrimination for yield control, aging monitoring, and system redundancy protection.

An LLC converter includes an LLC resonant tank, a first synchronous rectifier and a synchronous rectification controller. The LLC resonant tank includes a primary winding of a transformer including a first secondary winding. The first synchronous rectifier is connected in series with the first secondary winding through a first detection node and between an output power line and an output ground line. The synchronous rectification controller draws current from the first detection node and to raise an operation power source on a filter capacitor supplying power to the synchronous rectification controller.

The application discloses a kind of digital control method and device for inhibiting synchronous rectifier converter shutdown stress, applied to synchronous rectifier converter, and synchronous rectifier converter is used to control the output rectification process of switching power supply, the digital control method includes: based on the preset digital control program continuously detects whether switching power supply appears fault;When determining that switching power supply appears fault, then wait for the drive rising edge signal of switch tube in synchronous rectifier converter;When receiving drive rising edge signal, based on the preset digital control program and the drive rising edge signal, close synchronous rectifier converter PWM control, and then inhibit synchronous rectifier converter shutdown stress.The application closes synchronous rectifier converter PWM control when the inductance current of synchronous rectifier converter is positive current, avoids the stress problem of synchronous rectifier tube caused by synchronous rectifier converter inductance negative current under no-load and light load conditions, and then can effectively inhibit synchronous rectifier converter shutdown stress.

The invention discloses a software and hardware combined LLC synchronous rectification driving optimization circuit which comprises an LLC resonance network, a transformer T, a synchronous rectification circuit and a control module MCU which are connected in sequence. The first synchronous rectifier tube control circuit and the second synchronous rectifier tube control circuit respectively comprise a synchronous rectifier tube driving circuit and a synchronous rectifier tube voltage stress detection circuit. The turn-off of the synchronous rectifier tube is controlled by the control module MCU, and when the synchronous rectifier tube voltage stress detection circuit of the branch detects that the drain voltage of the synchronous rectifier tube of the other branch reaches a preset value, the synchronous rectifier tube of the branch is conducted, so that the dead time of t4-t5 is controlled, the dead time of t4-t5 is reduced to the maximum extent under the condition that safety is guaranteed, and the safety is improved. The switch-on time of the synchronous rectification MOS tube is increased, the efficiency of the converter is improved, the synchronous rectification MOS tube is ensured not to be directly connected, and the reliability of a power supply is guaranteed.

A power converter includes two control switches, two synchronous rectifier switches, two inductors, a voltage detector that detects a voltage across one of the control switches, and a controller that controls each switch to shift on and off phases of one of the control switches and one of the synchronous rectifier switches by 180° from on and off phases of the other control switch and the other synchronous rectifier switch. The controller determines the on-time of the target synchronous rectifier switch in accordance with the voltage across the one control switch after a lapse of a predetermined time period since turn-off of the one synchronous rectifier switch, and determines the on-time of the other synchronous rectifier switch as the determined on-time of the target synchronous rectifier switch.

In described examples, a switch controller (118) may be configured to activate a first rectification switch (114) of an output stage (104) of a power supply system (100) in a first state to provide a secondary current from a secondary winding of a first transformer (106), thereby generating an output voltage at the output stage (104) in response to detecting that the secondary current of the first direction passes through the secondary winding of the second transformer (116). And, the switch controller (118) may be configured to activate, in a second state, a second rectification switch (114) of the output stage (104) of the power supply system (100) to provide the secondary current from the secondary winding of the first transformer (106), thereby generating the output voltage at the output stage (104) in response to detecting that the secondary current of a second direction passes through the secondary winding of the second transformer (116).

Zero voltage switching with a secondary switch (e.g., a synchronous rectifier) is described herein. The method allows a secondary side controller to calculate a required secondary switch hold time. By measuring a forward pin voltage when the primary switch is conducting, the required secondary switch hold time may be determined without the need for primary to secondary communication.

The application discloses a current mode staggered control converter and a control chip, wherein the converter comprises a VIN input power supply with a voltage of 20V-100V, forward transformers T1 and T2, two output paths formed by the transformers and subsequent devices, a capacitor C0 as a VCC pin filter capacitor, a resistor R3 as an RT pin resistor connected to the ground and used for controlling the frequency of an oscillator, capacitors C1 and C2 as COMP1 and COMP2 pin capacitors connected to the ground and used for adjusting loop stability, capacitors C3 and C4 as SS1 and SS2 pin capacitors connected to the ground and used for realizing soft start of the system, N3 and N4 as natural synchronous rectifier devices in the forward converter, the first output channel and the second output channel adopting the same structure, an auxiliary winding La providing power supply for an IC control chip VCC through a diode D1, and an output capacitor Cout1 as an output capacitor of the first channel. The whole system is driven and controlled by only one control chip, and the power density is improved, the volume of the scheme is reduced, the cost of the scheme is lowered, and the system performance is not sacrificed.

According to an embodiment of the present disclosure, provided is a bidirectional LDC (Low DC-DC Converter) having opposite ends connected to a high voltage battery and a low voltage battery, respectively, and including a lossless snubber circuit, wherein, when any one of a first synchronous rectifier and a second synchronous rectifier is turned on, a voltage of a low voltage side connected to the low voltage battery is stepped up and transmitted to a high voltage side connected to the high voltage battery. When the first synchronous rectifier and the second synchronous rectifier are turned off, a first switch of the lossless snubber circuit is turned on to perform a voltage clamping operation and a freewheeling operation.

A wireless power transfer device is disclosed. In the wireless power transfer device (1), power is wirelessly transferred from the primary side (2) to the secondary side (3) across an air gap (8) by means of a primary resonator (6) that generates a magnetic field (9) and a secondary resonator (10) that receives power by picking up the magnetic field (9). The secondary side (3) includes an output stage (11) that receives AC power provided by the secondary resonator (10) and generates a DC output (13) to be provided to a load. A current sensing device (18) senses the AC current flowing from the secondary resonator (10) to the output stage (11) and provides a current sensing signal (16) to a power transfer controller (15), which controls the power transfer of the wireless power transfer device (1) based on the current sensing signal (16). Furthermore, the current sensing signal (16) is provided to the switch controller (20), which controls the switching of the synchronous rectifier of the output stage (11), which converts the AC power (12) provided by the secondary resonator (10) into DC output (13).

The invention relates to the technical field of power electronic conversion, in particular to a front-stage bidirectional AC-DC converter of a vehicle-mounted charger, which comprises an input filter circuit, an interleaved parallel totem pole power stage, an energy storage circuit, a driving and control circuit and a sampling and protecting circuit. The totem pole power level adopts two groups of silicon carbide MOSFET high-frequency switch tubes and low-frequency synchronous rectifier tubes which alternately work in the positive and negative half cycles of the power frequency, and the two paths are staggered by 180 degrees to operate. The control circuit adopts a double-loop control strategy of a DC bus voltage outer loop and a proportional resonance current inner loop to realize power factor correction and bidirectional power flow. Through combination of the silicon carbide device and the optimized topology, the efficiency is improved by 5%-10%, the power density is improved by 30%-50%, the cost is reduced by 20%-30%, the multi-functional application of G2V, V2G and V2L is achieved, an all-around protection mechanism is integrated, and the multi-functional protection device is suitable for a complex vehicle-mounted environment. The problem that a power device of an existing converter is large in conduction loss and switching loss is solved.