WO2020062247A1

WO2020062247A1 - Synchronous rectifier circuit and rectifier device

Info

Publication number: WO2020062247A1
Application number: PCT/CN2018/109109
Authority: WO
Inventors: 赵德琦; 赵武; 吴壬华
Original assignee: 深圳欣锐科技股份有限公司
Priority date: 2018-09-30
Filing date: 2018-09-30
Publication date: 2020-04-02
Also published as: CN110199465A; CN110199465B

Abstract

A synchronous rectifier circuit and a rectifier device. The synchronous rectifier circuit comprises a transformer (T1), a first rectifier circuit (210), a second rectifier circuit (220), a positive power source output end (Vout+), and a negative power source output end (Vout-). The transformer (T1) comprises a primary winding (L0), a first secondary winding (L1), and a second secondary winding (L2). The first end (L11) of the first secondary winding (L1) is connected to the first input end (211) of the first rectifier circuit (210), and the second end (L12) of the first secondary winding (L1) is connected to the second input end (212) of the first rectifier circuit (210), the second input end (222) of the second rectifier circuit (220), the first end (L21) of the second secondary winding (L2), and the negative power source output end (Vout-); the second end (L22) of the second secondary winding (L2) is connected to the first input end (221) of the second rectifier circuit (220); the output end (213) of the first rectifier circuit (210) is connected to the output end (223) of the second rectifier circuit (220) and the positive power source output end (Vout+). No additional power supply winding is required to be provided to the transformer (T1), thereby reducing the processing costs of the transformer, facilitating PCB wiring, and improving the power density of a power source.

Description

Synchronous rectifier circuit and rectifier

Technical field

The present application relates to the field of electronic technology, and particularly to a synchronous rectification circuit and a rectification device.

Background technique

Rectifying circuit is a circuit that converts AC power to DC power. Most rectifier circuits are composed of transformers, rectifier main circuits and filters. It is widely used in DC motor speed regulation, generator excitation regulation, electrolysis, electroplating and other fields. The rectifier circuit usually consists of a main circuit, a filter and a transformer.

In the application of the rectifier circuit, the synchronous rectifier circuit belongs to a relatively preferred circuit, as shown in FIG. 1. The conventional power supply method is to add an extra power supply winding to the transformer to power the rectifier circuit, which often has complicated lines, which increases the difficulty and cost of the transformer winding. In addition, when laying a board on a printed circuit board (Printed Circuit Board, PCB), it needs to occupy more PCB space, which is not conducive to improving the power density of the power supply.

Summary of the Invention

In order to solve the above-mentioned problems in the synchronous rectification circuit, the present application provides a synchronous rectification circuit and a rectification device, which can make the rectification circuit obtain the alternating current through the ground for rectification, omitting the power supply winding, more conducive to PCB wiring, and increasing the power density of the power supply. .

According to a first aspect of the embodiments of the present application, a synchronous rectification circuit is provided, which is applied to positive rectification and includes a transformer, a first rectification circuit, a second rectification circuit, a power output positive terminal and a power output negative terminal, wherein:

The transformer includes a primary winding, a first secondary winding, and a second secondary winding; a first end of the first secondary winding is connected to a first input end of the first rectifying circuit, and the first secondary winding A second terminal of is connected to a second input terminal of the first rectifier circuit, a second input terminal of the second rectifier circuit, a first terminal of the second secondary winding, and the power output negative terminal; The second end of the second secondary winding is connected to the first input end of the second rectification circuit; the output end of the first rectification circuit is connected to the output end of the second rectification circuit and the power output positive end;

When the polarity of the first end of the first secondary winding is positive and the polarity of the second end of the first secondary winding is negative, the first rectifying circuit implements a rectifying function;

When the polarity of the first end of the first secondary winding is negative and the polarity of the second end of the first secondary winding is positive, the second rectifying circuit implements a rectifying function.

In one embodiment, the first rectifier circuit includes: a first power control chip, a first switch tube, a first diode, a first resistor, and a first capacitor;

A second input terminal of the first rectifier circuit is connected to a positive electrode of the first diode, a negative electrode of the first diode is connected to a first terminal of the first resistor, and a second terminal of the first resistor is Terminal is connected to the first terminal of the first capacitor and the power supply terminal of the first power control chip, and the control terminal of the first power control chip is connected to the first terminal of the first switch tube; A first input terminal is connected to a second terminal of the first capacitor, a ground terminal of the first power control chip and a second terminal of the first switch tube, and a third terminal of the first switch tube is connected to the An output terminal of the first rectifying circuit.

In one embodiment, the second rectifier circuit includes: a second power control chip, a second switch tube, a second diode, a second resistor, and a second capacitor;

A second input terminal of the second rectifier circuit is connected to a positive electrode of the second diode, a negative electrode of the second diode is connected to a first terminal of the second resistor, and a second terminal of the second resistor The second terminal is connected to the first terminal of the second capacitor and the power supply terminal of the second power control chip, and the control terminal of the second power control chip is connected to the first terminal of the second switch tube; A second input terminal is connected to a second terminal of the second capacitor, a ground terminal of the second power control chip, and a second terminal of the second switch tube, and a third terminal of the second switch tube is connected to the An output terminal of the second rectifier circuit.

In one embodiment, when the polarity of the first input terminal of the first rectifier circuit is positive and the polarity of the second input terminal of the first rectifier circuit is negative, the first diode is not turned on. The first power chip drives the first switch to complete rectification, and at this time, the polarity of the first input terminal of the second rectifier circuit is negative, and the polarity of the second input terminal of the second rectifier circuit is positive The second diode is turned on, and the voltage between the first end and the second end of the second winding passes through the second diode and the second resistor to charge the second capacitor, so The function of the second capacitor to store electrical energy includes providing energy to the second power control chip.

In one embodiment, when the polarity of the first input terminal of the first rectifier circuit is negative and the polarity of the second input terminal of the first rectifier circuit is positive, the first diode is turned on, The voltage between the first end and the second end of the first winding passes through the first diode and the first resistor to charge the first capacitor. The function of the first capacitor to store electrical energy includes The first power control chip provides energy, at this time, the polarity of the first input terminal of the second rectifier circuit is positive, the polarity of the second input terminal of the second rectifier circuit is negative, and the second diode When not conducting, the second power chip drives the second switch to complete rectification.

In one embodiment, the first switching transistor and the second switching transistor include a metal oxide semiconductor field effect transistor (MOSFET).

In one embodiment, a drain of the metal-oxide-semiconductor field-effect transistor MOSFET is connected to the positive terminal of the power output.

In one embodiment, the synchronous rectification circuit further includes a filter circuit located between the positive terminal of the power output and the negative terminal of the power output.

In one embodiment, the filter circuit includes two filter capacitors connected in parallel.

According to a second aspect of the embodiments of the present application, a rectifying device is provided, which includes the synchronous rectifying circuit described in the first aspect of the embodiments of the present application.

An embodiment of the present application provides a synchronous rectification circuit, which includes a transformer, a first rectification circuit, a second rectification circuit, a power output positive terminal, and a power output negative terminal. The ground terminals of the first rectification circuit and the second rectification circuit are respectively connected to The first winding and the second winding of the transformer are connected, and there is no need to provide an additional power supply winding on the transformer, which reduces the transformer processing cost. For the occasion where the rectifier circuit and the transformer need to be separated, the power supply winding is omitted, which is more conducive to PCB wiring and improves the power density of the power supply.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to explain the technical solutions of the embodiments of the present application more clearly, the accompanying drawings used in the description of the embodiments are briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present application. Those skilled in the art can also obtain other drawings according to these drawings without paying creative labor.

FIG. 1 is a schematic structural diagram of a prior art synchronous rectification circuit;

FIG. 2 is a schematic structural diagram of a synchronous rectification circuit according to an embodiment of the present application; FIG.

FIG. 3 is a schematic diagram of a specific structure of a synchronous rectification circuit according to an embodiment of the present application; FIG.

4 is a schematic diagram of a specific structure of another synchronous rectifier circuit according to an embodiment of the present application;

FIG. 5 is a comparison diagram of voltage waveform changes in the embodiment of the present application.

detailed description

In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only These are part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

The terms “first”, “second”, and the like in the description and claims of the present application and the above-mentioned drawings are used to distinguish different objects, and are not used to describe a specific order. Furthermore, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, system, product, or device containing a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units not listed, or optionally includes Other steps or units inherent to the process, product, or equipment.

Reference to "an embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they independent or alternative embodiments that are mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

Please refer to FIG. 2, which is a schematic structural diagram of a synchronous rectification circuit according to an embodiment of the present application.

The present application provides a synchronous rectification circuit, which includes a transformer T1, a first rectification circuit 210, a second rectification circuit 220, a power output positive terminal Vout +, and a power output negative terminal Vout-;

The transformer T1 includes a primary winding L0, a first secondary winding L1, and a second secondary winding L2. A first terminal L11 of the first secondary winding L1 is connected to a first input terminal 211 of the first rectifier circuit 210. The second terminal L12 of the first secondary winding L1 is connected to the second input terminal 212 of the first rectifier circuit 210, the second input terminal 222 of the second rectifier circuit 220, and the negative output terminal Vout of the power supply. The second terminal L22 of the winding L2 is connected to the first input terminal 221 of the second rectifier circuit 220. The second terminal L22 of the first secondary winding L1 and the first terminal L21 of the second secondary winding L2 are the same port. The output terminal 213 of the first rectifier circuit 210 is connected to the output terminal 223 of the second rectifier circuit 220 and the power output positive terminal Vout +.

Through the above connection method, the first rectification circuit and the second rectification circuit are directly grounded, that is, the power is directly rectified through the transformer, and it is not necessary to provide an additional power supply winding on the transformer to power the first rectification circuit and the second rectification circuit, thereby reducing the transformer. Processing costs are more conducive to PCB wiring and improve power density.

In one embodiment, as shown in FIG. 3, the first rectifier circuit 210 shown in FIG. 3 includes a first power control chip 310, a first switch Q1, a first diode D1, a first resistor R1, a first Capacitor EC1; wherein the first switching transistor Q1 may be a transistor or a MOSFET. The following description uses the first switching transistor Q1 as a MOSFET as an example.

Optionally, the second terminal L12 of the first secondary winding L1 is connected to the positive electrode of the first diode D1, the negative electrode of the first diode D1 is connected to one end of the first resistor R1, and the first resistor R1 The other end is connected to one end of the first capacitor EC1 and the power supply terminal (Volt Current Condenser, VCC) of the first power control chip 310, and the control end of the first power control chip 310 is connected to the gate G of the first switch Q1. ; The first end L11 of the first secondary winding L1 is connected to the other end of the first capacitor EC1, the ground terminal (Ground, GND) of the first power control chip 310, and the source S of the first switch Q1, The drain D of the first switch Q1 is connected to the power output positive terminal Vout +.

In one embodiment, as shown in FIG. 3, the second rectifier circuit 220 includes a second power control chip 320, a second switch Q2, a second diode D2, a second resistor R2, and a second capacitor EC2; The second switching transistor Q2 may be a triode or a MOSFET. The following uses the second switching transistor Q2 as a MOSFET as an example for description.

Optionally, the first terminal L21 of the second secondary winding L2 is connected to the positive electrode of the second diode D2, the negative electrode of the second diode D2 is connected to one end of the second resistor R2, and the second resistor R2 The other end is connected to one end of the second capacitor EC2 and the power supply terminal VCC of the second power control chip 320, and the control end of the second power control chip 320 is connected to the gate G of the second switch Q2; the second secondary The second end L22 of the winding L2 is connected to the other end of the second capacitor EC2, the ground terminal GND of the second power control chip 320, the source S of the second switch Q2, and the drain D of the second switch Q2. Connect the above-mentioned power output negative terminal Vout-.

Using a MOSFET with extremely low on-resistance as a switching tube can greatly reduce the loss of the rectifier circuit, improve the efficiency of the DC / DC converter, and meet the needs of low-voltage and high-current rectifiers.

Optionally, as shown in FIG. 4, the synchronous rectification circuit provided in the embodiment of the present application may further include a filter circuit 230. The filter circuit 230 is connected between the power output positive terminal Vout + and the power output negative terminal Vout-. Further, The filter circuit 230 may include at least one filter capacitor. In this embodiment, the first filter capacitor C1 and the second filter capacitor C2 are used as an example. The first filter capacitor C1 and the second filter capacitor C2 are connected in parallel to the first rectifier circuit 210 and the first filter capacitor C2. The voltage rectified by the two rectifying circuits 220 is filtered.

The filtering circuit 230 works to convert the rectified pulsating DC power into smooth DC power.

With reference to FIGS. 2 to 4, the working principle of the synchronous rectification circuit provided in the present application is described below.

When the voltage polarity of the first secondary winding L1 of the transformer is positive, negative, and negative, the voltage of the first terminal L11 of the first secondary winding L1 is positive, and the voltage of the second terminal L12 of the first secondary winding L1 is negative. When the voltage at the first input terminal 211 of the first rectifier circuit 210 is positive and the voltage at the second input terminal 212 is negative, it can be understood that the positive voltage of the first diode D1 is negative at this time. The negative voltage is positive, and the first diode D1 is in a non-conducting state. At this time, the control terminal of the first power control chip 310 of the first rectifier circuit 210 sends a driving signal to the gate G of the first switch Q1. Realize synchronous rectification function; at this time, the voltage polarity of the second secondary winding L2 of the transformer is also positive, negative and negative, the first terminal voltage of the second secondary winding L2 is positive, and the voltage of the second terminal of the second secondary winding L2 It is negative. At this time, the voltage of the first input terminal 221 of the second rectifier circuit 220 is negative and the voltage of the second input terminal 222 is positive. It can be understood that at this time, the positive voltage of the second diode D2 is positive, and the second two The negative voltage of the electrode D2 is negative, the second diode D2 is in a conducting state, and the voltage passes through the second Diode D2, the second resistor R2, a second capacitor charge EC2, the second capacitor energy EC2 stored energy is released when the voltage polarity is reversed, the second power control chip 320 drives the second switching transistor Q2 to provide electrical power.

The driving signal may be a Pulse Width Modulation (PWM) signal. The first power control chip 310 may send a PWM signal to the gate G of the first switch Q1 through the control terminal to adjust the first rectifier circuit 210. The magnitude of the output voltage. The magnitude of the voltage output by the first rectifier circuit 210 is proportional to the duty cycle of the PWM signal.

When the voltage polarity of the first secondary winding L1 of the transformer is positive, negative and positive, the voltage of the first terminal L11 of the first secondary winding L1 is negative, and the voltage of the second terminal L12 of the first secondary winding L1 is positive. When the voltage of the first input terminal 211 of the first rectifier circuit 210 is negative, the voltage of the second input terminal 212 is positive, the positive voltage of the first diode D1 is positive, and the negative voltage of the first diode D1 is negative. The first diode D1 is in a conducting state, and the voltage passes through the first diode D1 and the first resistor R1 to charge a first capacitor EC1. The first capacitor EC1 stores electrical energy and releases energy when the voltage polarity is reversed To provide power for the first power control chip 310 to drive the first switch Q1. At this time, the voltage polarity of the second secondary winding L2 of the transformer is also positive, negative and positive, the voltage of the first terminal L21 of the second secondary winding L2 is negative, and the voltage of the second terminal L22 of the second secondary winding L2 is positive. At this time, the voltage of the first input terminal 221 of the second rectifier circuit 220 is positive, and the voltage of the second input terminal 222 is negative. It can be understood that the positive voltage of the second diode D2 is negative and the second diode D2 The negative voltage is positive, and the second diode D2 is in a non-conducting state. At this time, the control terminal of the second power control chip 320 of the second rectifier circuit 220 sends a driving signal to the gate G of the second switch Q2. To achieve synchronous rectification.

The driving signal may be a Pulse Width Modulation (PWM) signal. The second power control chip 320 may send a PWM signal to the gate G of the second switch Q2 through the control terminal to adjust the second rectifier circuit 220. The magnitude of the output voltage. The magnitude of the voltage output by the first rectifier circuit 220 is proportional to the duty cycle of the PWM signal.

When the first rectifying circuit 210 performs rectification, the second rectifying circuit 220 charges through the second capacitor EC2; when the voltage polarity is reversed and the second rectifying circuit 220 performs rectification, the first rectifying circuit 210 passes through the first capacitor EC1 performs charging, wherein the second rectifier circuit 220 obtains the electric energy that drives the second switching tube Q2 through the discharge of the second capacitor EC2. The above steps can be performed alternately in sequence with the periodic change of the polarity of the AC voltage.

Optionally, the pulsating DC power is processed by the filter circuit 230 after rectification to convert the pulsating DC power into a smoother DC power. The filter capacitor C1 and the filter capacitor C2 have polarities, one end is positive, and the other end is negative. The positive terminal is connected to the positive terminal of the power output, and the negative terminal is connected to the negative terminal of the power output.

Optionally, the filter capacitor may be a high-frequency filter capacitor, which is applied to the filtering after rectification of the switching power supply, including an electrolytic capacitor. At this time, the capacitance is not its main index. The criterion for measuring the pros and cons of high-frequency electrolytic capacitors is the "impedance-frequency" characteristic. It is required to have a lower equivalent impedance in the operating frequency of the switching power supply, and at the same time, it has a good filtering effect on the high-frequency spike signals generated during the operation of the semiconductor device.

Specifically, a high-frequency electrolytic capacitor dedicated to a switching power supply has four terminals, and two ends of a positive electrode are respectively drawn as a positive electrode of a capacitor, and two ends of a negative electrode are also drawn as a negative electrode. Current flows from one positive terminal of the four-terminal capacitor, passes through the capacitor, and then flows from the other positive terminal to the load; the current returned from the load also flows from one negative terminal of the capacitor, and then flows from the other negative terminal to the negative terminal of the power supply. Those skilled in the art can know that the capacitor is charged when the rectified voltage is higher than the capacitor voltage, and the capacitor is discharged when the rectified voltage is lower than the capacitor voltage. During the charging and discharging process, the output voltage is basically stable.

In all circuits that need to convert AC power to DC power, setting a filter capacitor will make the electronic circuit work more stable and reduce the interference of the alternating ripple on the electronic circuit. Filter capacitors can be connected in parallel to improve the efficiency of filtering.

With reference to FIG. 5, it can be understood that the AC voltage waveform of the voltage at the first end of the first secondary winding of the transformer and the second end of the second secondary winding has a square wave shape. It can be understood that when the AC voltage waveform is positive on the Y-axis When the shaft is half-axis, the voltage polarity corresponds to the positive polarity of the first secondary winding and the second secondary winding are positive, negative, and negative (that is, the first ends of the first secondary winding and the second secondary winding are positive, The second ends of the primary winding and the second secondary winding are negative). At this time, the first rectifying circuit rectifies the voltage between the first end and the second end of the first secondary winding, and at the same time The second capacitor in the rectifier circuit is charged; when the AC voltage waveform is on the negative half axis of the Y-axis, the voltage polarity corresponds to the voltage polarity of the first secondary winding and the second secondary winding being positive, negative, and positive (ie, the first The second ends of the primary winding and the second secondary winding are positive, and the first ends of the first secondary winding and the second secondary winding are negative). At this time, the second rectifier circuit The voltage between the first terminal and the second terminal is rectified, and the first capacitor in the first rectifying circuit is charged at the same time. Electricity; after rectification, it will pass through the filter circuit, and after filtering, a smoother DC voltage waveform will appear.

Optionally, the synchronous rectification circuit provided in this application is not only applicable to bridge circuits, but also applicable to other full-wave rectification circuits.

Compared with the existing synchronous rectifier circuit, a synchronous rectifier circuit provided in the embodiment of the present application includes a transformer, a first rectifier circuit, a second rectifier circuit, a positive power output terminal and a negative power output terminal, where the first rectifier circuit The ground terminal of the second rectifier circuit is connected to the first winding and the second winding of the transformer, respectively. It is not necessary to provide an additional power supply winding on the transformer, which reduces the processing cost of the transformer. For the occasion where the rectifier circuit and the transformer need to be separated, the power supply winding is omitted, which is more conducive to PCB wiring and improves the power density of the power supply.

An embodiment of the present application further provides a rectifying device, including the foregoing synchronous rectifying circuit, and details are not described herein again.

The embodiments of the present application have been described in detail above. Specific examples are used in this document to explain the principles and implementation of the present application. The descriptions of the above embodiments are only used to help understand the core idea of the present application. According to the idea of the present application, there may be changes in the specific implementation and the scope of application of the general technical person. In summary, the content of this description should not be construed as a limitation on the present application.

Claims

A synchronous rectification circuit, which is applied to positive rectification, is characterized in that the synchronous rectification circuit includes a transformer, a first rectification circuit, a second rectification circuit, a power output positive terminal and a power output negative terminal;

The transformer includes a primary winding, a first secondary winding, and a second secondary winding; a first end of the first secondary winding is connected to a first input end of the first rectifying circuit, and the first secondary winding A second terminal of is connected to a second input terminal of the first rectifier circuit, a second input terminal of the second rectifier circuit, a first terminal of the second secondary winding, and the power output negative terminal; The second end of the second secondary winding is connected to the first input end of the second rectification circuit; the output end of the first rectification circuit is connected to the output end of the second rectification circuit and the power output positive end;

When the polarity of the first end of the first secondary winding is positive and the polarity of the second end of the first secondary winding is negative, the first rectifying circuit implements a rectifying function;

When the polarity of the first end of the first secondary winding is negative and the polarity of the second end of the first secondary winding is positive, the second rectifying circuit implements a rectifying function.
The synchronous rectifier circuit according to claim 1, wherein the first rectifier circuit comprises: a first power control chip, a first switch tube, a first diode, a first resistor, and a first capacitor;

A second input terminal of the first rectifier circuit is connected to a positive electrode of the first diode, a negative electrode of the first diode is connected to a first terminal of the first resistor, and a second terminal of the first resistor is Terminal is connected to the first terminal of the first capacitor and the power supply terminal of the first power control chip, and the control terminal of the first power control chip is connected to the first terminal of the first switch tube; A first input terminal is connected to a second terminal of the first capacitor, a ground terminal of the first power control chip and a second terminal of the first switch tube, and a third terminal of the first switch tube is connected to the An output terminal of the first rectifying circuit.
The synchronous rectifier circuit according to claim 2, wherein the second rectifier circuit comprises: a second power control chip, a second switch tube, a second diode, a second resistor, and a second capacitor;

A second input terminal of the second rectifier circuit is connected to a positive electrode of the second diode, a negative electrode of the second diode is connected to a first terminal of the second resistor, and a second terminal of the second resistor The second terminal is connected to the first terminal of the second capacitor and the power supply terminal of the second power control chip, and the control terminal of the second power control chip is connected to the first terminal of the second switch tube; A second input terminal is connected to a second terminal of the second capacitor, a ground terminal of the second power control chip, and a second terminal of the second switch tube, and a third terminal of the second switch tube is connected to the An output terminal of the second rectifier circuit.
The synchronous rectifier circuit according to claim 3, wherein when the polarity of the first input terminal of the first rectifier circuit is positive and the polarity of the second input terminal of the first rectifier circuit is negative, all The first diode is non-conductive, the first power chip drives the first switch to complete rectification, and at this time, the first input terminal of the second rectifier circuit has a negative polarity, and the second rectifier circuit The polarity of the second input terminal is positive, the second diode is turned on, and the voltage between the first terminal and the second terminal of the second winding passes through the second diode and the second resistor, The second capacitor is charged, and the function of the second capacitor to store electrical energy includes providing energy to the second power control chip.
The synchronous rectifier circuit according to claim 3 or 4, wherein when the polarity of the first input terminal of the first rectifier circuit is negative and the polarity of the second input terminal of the first rectifier circuit is positive The first diode is turned on, and the voltage between the first end and the second end of the first winding passes through the first diode and the first resistor to charge the first capacitor, so The function of the first capacitor to store electrical energy includes providing energy to the first power control chip. At this time, the polarity of the first input terminal of the second rectifier circuit is positive, and the polarity of the second input terminal of the second rectifier circuit is positive. The performance is negative, the second diode is not conductive, and the second power chip drives the second switch to complete rectification.
The synchronous rectifier circuit according to claim 3, wherein the first switch tube and the second switch tube comprise a metal oxide semiconductor field effect transistor (MOSFET).
The synchronous rectification circuit according to claim 6, wherein a drain of the metal-oxide-semiconductor field-effect transistor (MOSFET) is connected to a positive terminal of the power output.
The synchronous rectification circuit according to claim 1, wherein the synchronous rectification circuit further comprises: a filter circuit between the power output positive terminal and the power output negative terminal.
The synchronous rectifier circuit according to claim 8, wherein the filter circuit comprises two filter capacitors connected in parallel.
A rectifier device, comprising the synchronous rectifier circuit according to any one of claims 1 to 9.