CN218867915U

CN218867915U - Protection circuit of SiC MOSFET

Info

Publication number: CN218867915U
Application number: CN202221194455.8U
Authority: CN
Inventors: 赵凤俭
Original assignee: Feicheng Semiconductor Shanghai Co ltd
Current assignee: Feicheng Semiconductor Shanghai Co ltd
Priority date: 2022-05-09
Filing date: 2022-05-09
Publication date: 2023-04-14
Anticipated expiration: 2032-05-09

Abstract

The technical scheme of this application provides a protection circuit of SiC MOSFET, includes: the output side logic control module is used for receiving and outputting the driving pulse signal of the SiC MOSFET and is also used for outputting a control signal synchronous with the driving pulse signal; the output stage power amplification circuit is electrically connected with the output side logic control module and is configured to amplify the driving pulse signal and output the driving pulse signal to the SiC MOSFET; and the soft turn-off module is electrically connected with the output side logic control module and the output stage power amplification circuit and is configured to gradually reduce the driving pulse voltage after the SiC MOSFET generates short circuit or overcurrent fault so as to realize the delayed turn-off of the driving pulse signal. According to the technical scheme, the protection circuit can realize delayed turn-off of the SiC MOSFET when the SiC MOSFET is in short circuit or overcurrent fault.

Description

Protection circuit of SiC MOSFET

Technical Field

The application relates to the technical field of power electronics, in particular to a protection circuit of a SiC MOSFET.

Background

Power electronic power converters play an important role in production and life as important devices for the utilization of electric energy. The core of the power electronic power converter is a power semiconductor device, which largely determines the performance of the power electronic power converter. At present, most power semiconductor devices are made of Si semiconductor materials, and the characteristics thereof are close to the theoretical limit, which becomes the bottleneck of further development of power electronic power converters. Compared with Si power devices, siC power devices have more excellent characteristics: the SiC power device has higher switching speed, can work at higher junction temperature, and can simultaneously realize high frequency, high voltage and large current. These characteristics can significantly improve the performance of the semiconductor power converter, obtain higher electric energy conversion efficiency, realize higher power density, reduce system cost, and the like.

In the power electronic converter, a control signal sent by a microcontroller belongs to a weak point signal, a power semiconductor device cannot be directly driven, and a driving circuit needs to be arranged between the microcontroller and the power semiconductor device. The driving circuit is mainly used for realizing on-off control of the power semiconductor device after shaping and power amplification of a weak current control signal sent by the microcontroller; when a fault occurs in the power semiconductor device and the circuit in which the power semiconductor device is located, the fault information is also transmitted back to the microcontroller by the driving circuit. Therefore, the driving circuit is a bridge for interaction between the weak current control signal and the strong current power circuit, and the reliability of the driving circuit directly influences the overall reliability of the power electronic converter.

The SiC MOSFET is mainly applied to high-voltage occasions, has high requirement on reliability, and can cause serious consequences if a circuit in which the SiC MOSFET is arranged is short-circuited or has an overcurrent fault, so that the SiC MOSFET must be protected after the short-circuit or overcurrent fault is detected. At present, hard turn-off is generally adopted, a driving circuit can immediately turn off the grid driving voltage of the SiC MOSFET, and the method always has the risk of over-voltage failure of the SiC MOSFET.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the application is to provide a protection circuit of a SiC MOSFET, which can realize the delayed turn-off of the SiC MOSFET when the SiC MOSFET has a short circuit or an overcurrent fault.

In order to solve the above technical problem, the present application provides a protection circuit of a SiC MOSFET, including: the output side logic control module is used for receiving and outputting the driving pulse signal of the SiC MOSFET and is also used for outputting a control signal synchronous with the driving pulse signal; the output stage power amplification circuit is electrically connected with the output side logic control module, is configured to amplify the driving pulse signal and outputs the driving pulse signal to the SiC MOSFET; and the soft turn-off module is electrically connected with the output side logic control module and the output stage power amplification circuit and is configured to gradually reduce the driving pulse voltage after the SiC MOSFET generates short circuit or overcurrent fault so as to realize the delayed turn-off of the driving pulse signal.

In some embodiments of the present application, the soft shutdown module is configured to perform the following operations after the SiC MOSFET has a short circuit or an overcurrent fault: in the first stage, the driving pulse voltage is reduced from a first positive voltage to a second positive voltage; in a second stage, reducing the driving pulse voltage from the second positive voltage to a third positive voltage; and performing a third stage when the driving pulse signal output by the output stage power amplifying circuit is a turn-off signal, so that the driving pulse voltage is reduced to a negative voltage from the third positive voltage.

In some embodiments of the present application, the soft shutdown module comprises: a gate of the fourth MOS transistor is electrically connected to the output side logic control module, and a source end of the fourth MOS transistor is electrically connected to the output side ground; a first end of the eighth capacitor is electrically connected with the output side ground; a first end of the thirteenth resistor is electrically connected with the drain end of the fourth MOS tube, and a second end of the thirteenth resistor is electrically connected with the second end of the eighth capacitor; a fourteenth resistor, a first end of which is electrically connected to the positive direct current voltage, and a second end of which is electrically connected to the second end of the eighth capacitor; the anode of the third diode is electrically connected with the output-stage power amplification circuit, and the cathode of the third diode is electrically connected with the second end of the eighth capacitor; a grid electrode of the fifth MOS tube is electrically connected with the output side logic control module, and a source end of the fifth MOS tube is connected with the output side ground; the anode of the second voltage stabilizing diode is electrically connected with the drain electrode of the fifth MOS tube, and the cathode of the second voltage stabilizing diode is electrically connected with the output stage power amplifying circuit; in the first stage, the output side logic control module sends a conducting signal to the fifth MOS transistor, and the fifth MOS transistor is conducted; in the second stage, the output side logic control module sends a conduction signal to the fourth MOS tube, and the fourth MOS tube is conducted; in the third stage, the output side logic control module sends a turn-off signal to the fourth MOS transistor and the fifth MOS transistor, and the fourth MOS transistor and the fifth MOS transistor are turned off.

In some embodiments of the present application, the output stage power amplifying circuit includes a push-pull driving circuit formed by a PMOS transistor and an NMOS transistor, or includes a push-pull driving circuit formed by an NPN transistor and a PNP transistor.

In some embodiments of the present application, the output stage power amplification circuit comprises: the input end of the amplifier is electrically connected with the output side logic control module, and the amplifier is also electrically connected with a direct current positive voltage, a direct current negative voltage and an output side ground; the source electrode of the PMOS tube is electrically connected with the direct-current voltage, the grid electrode of the PMOS tube is electrically connected with the output end of the amplifier, and the drain electrode of the PMOS tube is electrically connected with the grid electrode of the SiC MOSFET through a third resistor; and the source electrode of the NMOS tube is electrically connected with the direct-current negative voltage, the grid electrode of the NMOS tube is electrically connected with the output end of the amplifier, and the drain electrode of the NMOS tube is electrically connected with the grid electrode of the SiC MOSFET through a first resistor.

In some embodiments of the present application, the soft turn-off module is electrically connected to the drain of the NMOS transistor.

In some embodiments of the present application, the protection circuit further includes a short-circuit detection module, electrically connected to the output-side logic control module and the drain of the SiC MOSFET, for detecting whether the circuit in which the SiC MOSFET is located is short-circuited, and feeding back a short-circuit detection result to the output-side logic control module.

In some embodiments of the present application, the protection circuit further includes an input side logic control module, configured to receive a driving pulse signal of the SiC MOSFET, output the driving pulse signal to the output side logic control module, and further receive a short circuit detection result fed back by the output side logic control module.

In some embodiments of the present application, a first codec module is electrically connected between the input side logic control module and the output side logic control module, and the first codec module includes: the drive coding module is electrically connected with the input side logic control module; and the drive decoding module is in signal isolation with the drive coding module and is electrically connected with the output side logic control module.

In some embodiments of the present application, a second codec module is electrically connected between the input side logic control module and the output side logic control module, and the second codec module includes: the feedback coding module is electrically connected with the output side logic control module; and the feedback decoding module is in signal isolation with the feedback coding module and is electrically connected with the input side logic control module.

In some embodiments of the present application, the protection circuit further comprises: and the auxiliary detection module is positioned between the Kelvin pin and the source electrode pin of the SiC MOSFET and used for detecting the current change rate of the SiC MOSFET.

In some embodiments of the present application, the auxiliary detection module comprises: the anode of the second diode is connected with the output side ground; an eleventh resistor, a first end of which is electrically connected to the cathode of the second diode, and a second end of which is electrically connected to the source of the SiC MOSFET; a twelfth resistor, a first end of which is electrically connected to the cathode of the second diode; a first end of the seventh capacitor is electrically connected with a second end of the twelfth resistor, and a second end of the seventh capacitor is electrically connected with the source electrode of the SiC MOSFET; and the primary side of the transformer is electrically connected with two ends of the seventh capacitor, one end of the secondary side of the transformer is electrically connected with the output side logic control module, and the other end of the secondary side of the transformer is connected with the output side ground.

The protection circuit of this application technical scheme sets up soft turn-off module, takes place the short circuit or overflow fault after, can make drive pulse voltage reduce gradually for the drive pulse signal carries out the time delay and shuts off, has reduced SiC MOSFET's drain-source peak voltage effectively, has avoided adopting the present hard turn-off mode to lead to the fact too high drain-source peak voltage when shutting off grid drive voltage, and then leads to damaging SiC MOSFET's problem, has good protection effect to SiC MOSFET.

Drawings

The following drawings describe in detail exemplary embodiments disclosed in the present application. Wherein like reference numerals represent similar structures throughout the several views of the drawings. Those of ordinary skill in the art will understand that the present embodiments are non-limiting, exemplary embodiments and that the accompanying drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of the present application, as other embodiments may equally fulfill the inventive intent of the present application. It should be understood that the drawings are not to scale. Wherein:

fig. 1 is a schematic structural diagram of a protection circuit of a SiC MOSFET according to an embodiment of the present application;

fig. 2 is a diagram of a state of change of a driving pulse voltage of the soft shutdown module according to the embodiment of the present application after the SiC MOSFET has a short circuit or an overcurrent fault;

fig. 3 is a schematic structural diagram of a protection circuit of another SiC MOSFET according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a protection circuit of a further SiC MOSFET according to an embodiment of the present application.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only examples or embodiments of the application, from which the application can also be applied to other similar scenarios without inventive effort for a person skilled in the art. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

It should be understood that "module," "circuit," as used herein, is a method for distinguishing different components, elements, components, portions or assemblies at different levels. However, other words may be substituted by other expressions if they accomplish the same purpose.

The terminology used in the description presented herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. For example, as used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," and/or "including," when used in this specification, are intended to specify the presence of stated integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. When different components are described in this specification as being associated, they may be in a direct relationship or an indirect relationship. For example, "a and B are connected" may be that a and B are directly connected, or that a and B are indirectly connected through other components.

These and other features disclosed herein, as well as the operation and function of the related elements of structure and the combination of parts and economies of manufacture, may be significantly improved upon consideration of the following description. All of which form a part of the disclosure of this specification, with reference to the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the present disclosure. Flow charts are used herein to illustrate operations performed by systems according to embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in the exact order in which they are performed. Rather, the various steps may be processed in reverse order or simultaneously. Meanwhile, other operations may be added to the processes, or a certain step or several steps of operations may be removed from the processes.

The following description is presented to enable any person skilled in the art to make and use the present disclosure, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present application. Thus, the present application is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the claims.

At present, when a short circuit or overcurrent fault occurs in a SiC MOSFET, a hard turn-off mode is adopted to turn off a grid driving voltage of the SiC MOSFET so as to rapidly turn off a fault current, but the hard turn-off can cause an overhigh current change rate (di/dt), and under the action of stray inductance, the overhigh di/dt can generate overhigh V _DS Spike voltage, there is a risk of over-voltage failure of the SiC MOSFET.

Therefore, the protection circuit of the SiC MOSFET can gradually reduce the driving pulse voltage, further realize the delayed turn-off of the driving pulse signal, and effectively reduce the drain-source peak voltage of the SiC MOSFET, thereby protecting the SiC MOSFET.

Referring to fig. 1, an embodiment of the present application provides a protection circuit of a SiC MOSFET, including: the device comprises an output side logic control module, an output stage power amplifying circuit and a soft turn-off module. The output side logic control module is used for receiving and outputting the driving pulse signal of the SiC MOSFET and is also used for outputting a control signal synchronous with the driving pulse signal. The output stage power amplification circuit is electrically connected with the output side logic control module, and is configured to amplify the driving pulse signal and output the driving pulse signal to the SiC MOSFET. The soft turn-off module is electrically connected with the output side logic control module and the output stage power amplification circuit and is configured to gradually reduce the driving pulse voltage after the SiC MOSFET is in short circuit or overcurrent fault so as to realize delayed turn-off of the driving pulse signal. The driving pulse voltage can be regarded as the grid source voltage V of the SiC MOSFET _GS 。

Referring to fig. 2, the soft shutdown module is configured to perform the following operations after the SiC MOSFET has a short circuit or an overcurrent fault: in the first stage, the driving pulse voltage is reduced from a first positive voltage V1 to a second positive voltage V2, the first positive voltage V1 may be a direct current positive voltage VCC, and the second positive voltage V2 is determined according to a specific structure of a specific soft turn-off module; in the second stage, the driving pulse voltage is reduced from the second positive voltage V2 to a third positive voltage V3, wherein the third positive voltage V3 depends on the specific structure of a specific soft turn-off module; and when the driving pulse signal output by the output stage power amplifying circuit is a turn-off signal, performing a third stage to reduce the driving pulse voltage from the third positive voltage V3 to a negative voltage V4, where the negative voltage V4 may be a direct current negative voltage VEE.

Referring to fig. 3, the soft shutdown module 400 may include: a fourth MOS transistor M4, an eighth capacitor C8, a thirteenth resistor R13, a fourteenth resistor R14, a third diode, a fifth MOS transistor M5, and a second zener diode T2. The gate of the fourth MOS transistor M4 is electrically connected to the output-side logic control module, the source of the fourth MOS transistor M4 is electrically connected to the output-side ground GND, the drain of the fourth MOS transistor M4 is electrically connected to the first end of the thirteenth resistor R13, the second end of the thirteenth resistor R13 is electrically connected to the second end of the eighth capacitor C8, and the first end of the eighth capacitor C8 is electrically connected to the output-side ground GND. A first end of the fourteenth resistor R14 is electrically connected to the positive dc voltage VCC, and a second end of the fourteenth resistor R14 is electrically connected to a second end of the eighth capacitor C8. The anode of the third diode Z3 is electrically connected to the output stage power amplifying circuit 300, and the cathode of the third diode Z3 is electrically connected to the second end of the eighth capacitor C8. The gate of the fifth MOS transistor M5 is electrically connected to the output side logic control module, the source of the fifth MOS transistor M5 is connected to the output side ground GND, the drain of the fifth MOS transistor M5 is electrically connected to the anode of the second voltage regulator diode T2, and the cathode of the second voltage regulator diode T2 is electrically connected to the output stage power amplification circuit 300.

In the first stage of turn-off, the output side logic control module sends a turn-on signal to the fifth MOS tube M5, the fifth MOS tube M5 is turned on, and the driving pulse voltage is reduced by the direct-current positive voltage VCCVoltage drop V to the second zener diode _T2 In the second stage, the output side logic control module sends a conducting signal to the fourth MOS transistor M4, the fourth MOS transistor M4 is conducted, and the driving pulse voltage is driven by V _T2 Voltage drop V reduced to the thirteenth resistor R13 _R13 (ii) a In the third stage, the output side logic control module sends a turn-off signal to the fourth MOS transistor M4 and the fifth MOS transistor M5, and the fourth MOS transistor M4 and the fifth MOS transistor M5 are both turned off, so that the driving pulse signal is turned off, and the driving pulse voltage is driven by V _R13 And reducing to direct current negative pressure VEE.

According to the embodiment of the application, the soft turn-off module is adopted, so that the driving pulse voltage is gradually reduced when a circuit where the SiC MOSFET is located is in a short circuit or overcurrent fault, the delayed turn-off of a driving pulse signal is realized, the drain source peak voltage of the SiC MOSFET is reduced, the phenomenon that the grid driving voltage is immediately turned off in the existing hard turn-off mode is avoided, and the problem that the SiC MOSFET is damaged due to the overhigh drain source peak voltage when the fault current is quickly turned off is solved.

The output stage power amplifying circuit can be a totem-pole structure built by adopting a power operational amplifier or a discrete element and is used for amplifying the power of the driving signal. By way of example, the output stage power amplifying circuit may be a push-pull driving circuit including a PMOS transistor and an NMOS transistor, or a push-pull driving circuit including NPN and PNP transistors.

With continued reference to fig. 3, the output stage power amplifying circuit 300 according to the embodiment of the present application is, for example, a push-pull driving circuit including a PMOS transistor and an NMOS transistor. Specifically, the output stage power amplifying circuit 300 may include an amplifier, a PMOS transistor P, an NMOS transistor N, and a third resistor R3 as an output resistor, and may further include a first resistor R1 as a turn-off resistor. The input end of the amplifier is electrically connected with the output side logic control module, and the amplifier is also electrically connected with a direct current positive voltage VCC, a direct current negative voltage VEE and an output side ground GND. The source electrode of the PMOS tube P is electrically connected with the direct-current voltage VCC, the grid electrode of the PMOS tube P is electrically connected with the output end of the amplifier, and the drain electrode of the PMOS tube P is electrically connected with the grid electrode of the SiC MOSFET through the third resistor R3. The source electrode of the NMOS tube N is electrically connected with the direct-current negative voltage VEE, the grid electrode of the NMOS tube N is electrically connected with the output end of the amplifier, and the drain electrode of the NMOS tube N is electrically connected with the grid electrode of the SiC MOSFET through a first resistor R1.

It should be noted that the soft shutdown module 400 of the embodiment of the present application needs to be electrically connected to the negative voltage output terminal of the output stage power amplifying circuit 300. As an example, the soft turn-off module 400 may be electrically connected to the drain of the NMOS transistor N.

The circuit structure of the output side logic control module only needs to be capable of receiving the drive pulse signal of the SiC MOSFET and outputting the drive pulse signal to the output stage power amplification circuit, and can output a control signal synchronized with the drive pulse signal to the soft turn-off module.

The protection circuit can further comprise a short-circuit detection module, wherein the short-circuit detection module is electrically connected with the output side logic control module and the drain electrode of the SiC MOSFET and is used for detecting whether a circuit where the SiC MOSFET is located is short-circuited or not and feeding back a short-circuit detection result to the output side logic control module.

The protection circuit can further comprise an input side logic control module, wherein the input side logic control module is used for receiving the drive pulse signal of the SiC MOSFET and outputting the drive pulse signal to the output side logic control module, and the input side logic control module is also used for receiving a short circuit detection result fed back by the output side logic control module. The specific structure of the input side logic control module is not limited, and any circuit structure capable of realizing the above functions may be adopted.

Referring to fig. 4, a first codec module is electrically connected between the input side logic control module and the output side logic control module, and includes: the drive coding module is electrically connected with the input side logic control module; and the driving decoding module is in signal isolation with the driving coding module and is electrically connected with the output side logic control module.

And a second coding and decoding module can be electrically connected between the input side logic control module and the output side logic control module. The second codec module includes: the feedback coding module is electrically connected with the output side logic control module; and the feedback decoding module is in signal isolation with the feedback coding module and is electrically connected with the input side logic control module.

The protection circuit may further include: and the auxiliary detection module is positioned between the Kelvin pin K and the source pin of the SiC MOSFET and is used for detecting the current change rate (di/dt) of the SiC MOSFET. The current change rate of the SiC MOSFET is not detected by the existing driving circuit, and the SiC MOSFET has larger di/dt under the conditions of normal operation, short-circuit fault, overcurrent fault and the like, so that the embodiment of the application adopts a device in a Kelvin pin packaging form, and di/dt parameters are measured from parasitic reactance between the Kelvin pin and a source electrode pin and can be used as an auxiliary criterion for short-circuit or overcurrent fault.

In some embodiments, the auxiliary detection module 200 includes a second diode Z2, an eleventh resistor R11, a twelfth resistor R12, a seventh capacitor C7, and a transformer, an anode of the second diode Z2 and the kelvin pin are all connected to the output side ground GND, a cathode of the second diode Z2 is electrically connected to a first end of the eleventh resistor R11, and a second end of the eleventh resistor R11 is electrically connected to the source S of the SiC MOSFET. A first end of the twelfth resistor R12 is electrically connected to the cathode of the second diode Z2, a second end of the twelfth resistor R12 is electrically connected to a first end of the seventh capacitor C7, and a second end of the seventh capacitor C7 is electrically connected to the source S of the SiC MOSFET. The primary side of the transformer is electrically connected with two ends of the seventh capacitor C7, one end of the secondary side of the transformer is electrically connected with the output side logic control module, and the other end of the secondary side of the transformer is connected with the output side ground GND.

An embodiment of the present application further provides a protection method for a SiC MOSFET, which uses any one of the protection circuits described above, and the protection method includes: determining that the SiC MOSFET has short circuit or overcurrent fault; the soft turn-off module gradually reduces the driving pulse voltage to realize the delayed turn-off of the driving pulse signal.

In some embodiments, the method for gradually reducing the driving pulse voltage by the soft shutdown module to achieve delayed shutdown of the driving pulse signal may include: in the first stage, the driving pulse voltage is reduced from a first positive voltage to a second positive voltage; in a second stage, reducing the driving pulse voltage from the second positive voltage to a third positive voltage; and when the driving pulse signal is a turn-off signal, performing a third stage to reduce the driving pulse voltage from the third positive voltage to a negative voltage.

In view of the above, it will be apparent to those skilled in the art upon reading the present application that the foregoing application content may be presented by way of example only, and may not be limiting. Those skilled in the art will appreciate that the present application is intended to cover various reasonable variations, adaptations, and modifications of the embodiments described herein, even though not expressly described herein. Such alterations, modifications, and variations are intended to be within the spirit and scope of the exemplary embodiments of this application.

It will be further understood that, although the terms first, second, third, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element in some embodiments may be termed a second element in other embodiments without departing from the teachings of the present application. The same reference numerals or the same reference characters denote the same elements throughout the specification.

Claims

1. A protection circuit for a SiC MOSFET, comprising:

the output side logic control module is used for receiving and outputting the driving pulse signal of the SiC MOSFET and is also used for outputting a control signal synchronous with the driving pulse signal;

the output stage power amplification circuit is electrically connected with the output side logic control module, is configured to amplify the driving pulse signal and outputs the driving pulse signal to the SiC MOSFET;

and the soft turn-off module is electrically connected with the output side logic control module and the output stage power amplification circuit and is configured to gradually reduce the driving pulse voltage after the SiC MOSFET generates short circuit or overcurrent fault so as to realize the delayed turn-off of the driving pulse signal.

2. The protection circuit of the SiC MOSFET of claim 1, wherein the soft turn-off module comprises:

a gate of the fourth MOS transistor is electrically connected to the output side logic control module, and a source end of the fourth MOS transistor is electrically connected to the output side ground;

a first end of the eighth capacitor is electrically connected with the output side ground;

a first end of the thirteenth resistor is electrically connected with a drain end of the fourth MOS transistor, and a second end of the thirteenth resistor is electrically connected with a second end of the eighth capacitor;

a fourteenth resistor, a first end of which is electrically connected to the positive direct current voltage, and a second end of which is electrically connected to the second end of the eighth capacitor;

the anode of the third diode is electrically connected with the output-stage power amplification circuit, and the cathode of the third diode is electrically connected with the second end of the eighth capacitor;

a grid electrode of the fifth MOS tube is electrically connected with the output side logic control module, and a source end of the fifth MOS tube is connected with the output side ground;

the anode of the second voltage stabilizing diode is electrically connected with the drain electrode of the fifth MOS tube, and the cathode of the second voltage stabilizing diode is electrically connected with the output stage power amplifying circuit;

in the first stage, the output side logic control module sends a conducting signal to the fifth MOS tube, and the fifth MOS tube is conducted; in the second stage, the output side logic control module sends a conduction signal to the fourth MOS tube, and the fourth MOS tube is conducted; in a third stage, the output side logic control module sends a turn-off signal to the fourth MOS transistor and the fifth MOS transistor, and the fourth MOS transistor and the fifth MOS transistor are turned off.

3. The protection circuit of the SiC MOSFET as recited in claim 1, wherein the output stage power amplification circuit comprises a push-pull driving circuit formed by PMOS transistor and NMOS transistor, or comprises a push-pull driving circuit formed by NPN and PNP triode.

4. The protection circuit of the SiC MOSFET of claim 3, wherein the output stage power amplification circuit comprises:

the input end of the amplifier is electrically connected with the output side logic control module, and the amplifier is also electrically connected with a direct current positive voltage, a direct current negative voltage and an output side ground;

the source electrode of the PMOS tube is electrically connected with the direct-current positive voltage, the grid electrode of the PMOS tube is electrically connected with the output end of the amplifier, and the drain electrode of the PMOS tube is electrically connected with the grid electrode of the SiC MOSFET through a third resistor;

and the source electrode of the NMOS tube is electrically connected with the direct-current negative voltage, the grid electrode of the NMOS tube is electrically connected with the output end of the amplifier, and the drain electrode of the NMOS tube is electrically connected with the grid electrode of the SiC MOSFET through a first resistor.

5. The protection circuit of the SiC MOSFET as recited in claim 4, wherein the soft turn-off module is electrically connected with a drain of the NMOS tube.

6. The protection circuit of the SiC MOSFET of claim 1, further comprising a short detection module electrically connected to the output side logic control module and a drain of the SiC MOSFET for detecting whether a circuit in which the SiC MOSFET is located is short-circuited and feeding back a short detection result to the output side logic control module.

7. The protection circuit of the SiC MOSFET as recited in claim 6, further comprising an input side logic control module for receiving the driving pulse signal of the SiC MOSFET and outputting the driving pulse signal to the output side logic control module, and further for receiving the short circuit detection result fed back by the output side logic control module.

8. The protection circuit of the SiC MOSFET of claim 7, wherein a first codec module is electrically connected between the input side logic control module and the output side logic control module, and the first codec module comprises:

the drive coding module is electrically connected with the input side logic control module;

and the driving decoding module is in signal isolation with the driving coding module and is electrically connected with the output side logic control module.

9. The protection circuit of the SiC MOSFET of claim 7, wherein a second codec module is electrically connected between the input side logic control module and the output side logic control module, and the second codec module comprises:

the feedback coding module is electrically connected with the output side logic control module;

and the feedback decoding module is in signal isolation with the feedback coding module and is electrically connected with the input side logic control module.

10. The protection circuit of the SiC MOSFET of claim 1, further comprising: and the auxiliary detection module is positioned between the Kelvin pin and the source electrode pin of the SiC MOSFET and used for detecting the current change rate of the SiC MOSFET.

11. The protection circuit of the SiC MOSFET of claim 10, wherein the auxiliary detection module comprises:

the anode of the second diode is connected with the output side ground;

an eleventh resistor, a first end of which is electrically connected to the cathode of the second diode, and a second end of which is electrically connected to the source of the SiC MOSFET;

a twelfth resistor, a first end of the twelfth resistor being electrically connected to the cathode of the second diode;

a first end of the seventh capacitor is electrically connected with a second end of the twelfth resistor, and a second end of the seventh capacitor is electrically connected with the source electrode of the SiC MOSFET;

and the primary side of the transformer is electrically connected with two ends of the seventh capacitor, one end of the secondary side of the transformer is electrically connected with the output side logic control module, and the other end of the secondary side of the transformer is connected with the output side ground.