MOSFET short circuit protection and locking circuit and method

Abstract

The invention discloses an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) short-circuit protection and locking circuit and method. The circuit comprises an MOSFET driving module, an MOSFET function module and a protection locking module, the MOSFET driving module is used for outputting an MOSFET driving signal so as to turn on or turn off the MOSFET; the MOSFET function module realizes a preset function by turning on or turning off the MOSFET; the MOSFET function module comprises an MOSFET and a first resistor connected to the MOSFET, and the first resistor is used for sampling the working current of the MOSFET; and the protection locking module is used for comparing the first voltage of the first resistor with a preset voltage threshold through the comparator, turning off the MOSFET according to a comparison result, and keeping the turn-off state of the MOSFET. The application is beneficial to improving the response speed and precision. The method can be widely applied to the technical field of short-circuit protection circuit design.

Description

Technical Field

[0001] The present invention relates to the technical field of short-circuit protection circuit design, in particular to a MOSFET short-circuit protection and locking circuit and method. Background Art

[0002] MOSFETs offer the advantages of high-temperature resistance and low switching losses, but they have higher short-circuit currents than IGBTs. Combined with their smaller chip area, short circuits can cause greater thermal stress. A widely used approach in circuit design is to use a current sensor to directly monitor the MOSFET's operating current. When the current exceeds a set protection threshold, a short circuit is detected.

[0003] In related technologies, a sampling resistor is typically connected in series with the busbar. The sampling signal is then transmitted to the motherboard via an op amp, which then issues a protection signal to initiate the protection operation. Controlling short-circuit protection via the motherboard results in a response time and limited accuracy. Summary of the Invention

[0004] The purpose of the present invention is to solve one of the technical problems existing in the prior art to at least a certain extent.

[0005] Therefore, the object of the present invention is to provide an efficient MOSFET short-circuit protection and locking circuit and method.

[0006] In order to achieve the above technical objectives, the technical solutions adopted by the embodiments of the present invention include the following aspects:

[0007] On the one hand, an embodiment of the present invention provides a MOSFET short-circuit protection and locking circuit, comprising: a MOSFET driving module, a MOSFET functional module, and a protection locking module; the MOSFET driving module is used to output a MOSFET driving signal to turn the MOSFET on or off; the MOSFET functional module realizes a preset function by turning the MOSFET on or off; the MOSFET functional module includes the MOSFET and a first resistor connected to the MOSFET, the first resistor being used to sample the working current of the MOSFET; the protection locking module is used to compare the first voltage of the first resistor with a preset voltage threshold through a comparator, and according to the comparison result, turn off the MOSFET and maintain the off state of the MOSFET. The present application realizes sampling of the working current through the first resistor, realizes short-circuit protection and locking through the comparator, and realizes short-circuit protection and locking of the MOSFET through the circuit, which is conducive to improving response speed and accuracy.

[0008] In addition, the MOSFET short-circuit protection and locking circuit according to the above embodiment of the present invention may also have the following additional technical features:

[0009] Furthermore, in the MOSFET short-circuit protection and locking circuit of an embodiment of the present invention, the protection locking module includes a protection unit and a locking unit; the protection unit includes a comparator and a first transistor, and the first transistor is used to receive the output signal of the comparator to turn off the MOSFET; the locking unit includes an optocoupler and a second transistor, and the optocoupler is used to receive the output signal of the comparator and, in combination with the second transistor, maintain the off state of the MOSFET.

[0010] Furthermore, in one embodiment of the present invention, the protection unit also includes a first diode, a second resistor, and a third resistor; the non-phase input terminal of the comparator is grounded through a first capacitor, the inverting input terminal of the comparator is connected to the power supply through a second resistor and to the ground through a third resistor, the output terminal of the comparator is connected to the base of the first transistor through a first diode, and the output terminal of the comparator is also connected to the light-emitting anode of the optocoupler through the first diode; the emitter of the first transistor is grounded, and the collector of the first transistor is connected to the drive signal output terminal of the MOSFET drive module; the voltage stored in the first capacitor is the voltage of the first resistor after being divided by the voltage divider circuit.

[0011] Furthermore, in one embodiment of the present invention, the locking unit is used to maintain the off state of the MOSFET or restart the MOSFET based on a locking signal; the locking signal is input into the base of the second transistor, the collector of the second transistor is connected to the power supply, the emitter of the second transistor is connected to the collector of the optocoupler, the emitter of the optocoupler is connected to the base of the first transistor, the emitter of the optocoupler is also connected to the light-emitting anode of the optocoupler, and the light-emitting cathode of the optocoupler is grounded.

[0012] Furthermore, in one embodiment of the present invention, the MOSFET functional module includes a push-pull output circuit, the push-pull output circuit includes a first MOSFET, a second MOSFET and a transformer, the transformer includes a first input winding and a second input winding; the gates of the first MOSFET and the second MOSFET are used to receive the drive signal of the MOSFET drive module, the sources of the first MOSFET and the second MOSFET are connected to the first resistor, the drain of the first MOSFET is connected to the first input end of the first input winding, the drain of the second MOSFET is connected to the second input end of the second input winding, and the second input end of the first input winding and the first input end of the second input winding are both connected to a power supply.

[0013] Furthermore, in one embodiment of the present invention, the driving signal of the MOSFET driving module includes a first PWM signal and a second PWM signal, and the level states of the first PWM signal and the second PWM signal are opposite;

[0014] The first PWM signal is input into the MOSFET functional module through a fourth resistor, and the second MOSFET functional module is input into the MOSFET functional module through a fifth resistor.

[0015] Furthermore, in one embodiment of the present invention, the resistance of the first resistor is 0.001 to 0.003 ohms.

[0016] On the other hand, an embodiment of the present invention provides a MOSFET short-circuit protection and locking method, which is applied to the above-mentioned MOSFET short-circuit protection and locking circuit. The method includes:

[0017] Based on the MOSFET drive signal, drive the MOSFET to turn on or off to achieve the preset function;

[0018] A comparator compares a first voltage of a first resistor connected to the MOSFET with a preset voltage threshold, and according to a comparison result, turns off the MOSFET and maintains the MOSFET in the off state.

[0019] Furthermore, the MOSFET short-circuit protection and locking method according to an embodiment of the present invention further includes:

[0020] According to the comparison result, the MOSFET is turned off by the first transistor;

[0021] According to the comparison result, the MOSFET is kept in an off state through the optical coupler and the second transistor.

[0022] Furthermore, the MOSFET short-circuit protection and locking method according to an embodiment of the present invention further includes:

[0023] The MOSFET is restarted according to the received locking signal in the low level state.

[0024] The circuit provided by the embodiment of the present invention includes: a MOSFET driving module, a MOSFET functional module and a protection locking module; the MOSFET driving module is used to output a MOSFET driving signal to turn the MOSFET on or off; the MOSFET functional module realizes a preset function by turning the MOSFET on or off; the MOSFET functional module includes the MOSFET and a first resistor connected to the MOSFET, the first resistor being used to sample the working current of the MOSFET; the protection locking module is used to compare the first voltage of the first resistor with a preset voltage threshold through a comparator, and according to the comparison result, turn off the MOSFET and maintain the off state of the MOSFET. The present application realizes sampling of the working current through the first resistor, realizes short-circuit protection and locking through the comparator, and realizes short-circuit protection and locking of the MOSFET through the circuit, which is conducive to improving response speed and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following introduction is made to the drawings of the embodiments of the present invention or the related technical solutions in the prior art. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 A schematic structural diagram of an embodiment of a MOSFET short-circuit protection and locking circuit provided by the present invention;

[0027] Figure 2 An electrical schematic diagram of an embodiment of a MOSFET short-circuit protection and locking circuit provided by the present invention;

[0028] Figure 3 The present invention provides a flow chart of an embodiment of a MOSFET short-circuit protection and locking method. DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention. The step numbers in the following embodiments are provided for ease of explanation only and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0030] MOSFETs offer the advantages of high-temperature resistance and low switching losses, but they have higher short-circuit currents than IGBTs. Combined with their smaller chip area, short circuits can cause greater thermal stress. A widely used approach in circuit design is to use a current sensor to directly monitor the MOSFET's operating current. When the current exceeds a set protection threshold, a short circuit is detected.

[0031] Currently, to monitor circuit operation, a sampling resistor is typically connected in series with the busbar. The sampling signal is then transmitted to the mainboard via an op amp, which then issues a protection signal to initiate a protection operation. The circuit provided in this application implements short-circuit protection for any MOSFET in a push-pull output circuit by adding a sampling resistor to the MOSFET bridge arm. This allows for faster shutdown of the MOSFET and a protective lockout in the event of a short circuit.

[0032] The following describes in detail a MOSFET short-circuit protection and locking circuit and method according to an embodiment of the present invention with reference to the accompanying drawings. First, a MOSFET short-circuit protection and locking circuit according to an embodiment of the present invention is described with reference to the accompanying drawings.

[0033] Figure 1 This is a schematic diagram of the MOSFET short-circuit protection and locking circuit structure according to an embodiment of the present invention, which specifically includes:

[0034] MOSFET driver module, MOSFET function module and protection lock module;

[0035] The MOSFET driving module is used to output a MOSFET driving signal to turn the MOSFET on or off;

[0036] The MOSFET functional module realizes a preset function by turning on or off the MOSFET; the MOSFET functional module includes the MOSFET and a first resistor connected to the MOSFET, the first resistor being used to sample the operating current of the MOSFET;

[0037] The protection locking module is used to compare the first voltage of the first resistor with a preset voltage threshold through a comparator, and according to the comparison result, turn off the MOSFET and keep the MOSFET in the off state.

[0038] The MOSFET functional module in this application can be a circuit that implements any function through MOSFET. The protection locking module is used to compare the first voltage of the first resistor with a preset voltage threshold through a comparator, and when the MOSFET is short-circuited, turn off the MOSFET and keep it in the off state. Figure 2 As shown, it is a specific schematic diagram of a circuit provided by this application.

[0039] Furthermore, in the MOSFET short-circuit protection and locking circuit of an embodiment of the present invention, the protection locking module includes a protection unit and a locking unit; the protection unit includes a comparator and a first transistor, and the first transistor is used to receive the output signal of the comparator to turn off the MOSFET; the locking unit includes an optocoupler and a second transistor, and the optocoupler is used to receive the output signal of the comparator and, in combination with the second transistor, maintain the off state of the MOSFET.

[0040] Furthermore, in one embodiment of the present invention, the protection unit also includes a first diode, a second resistor, and a third resistor; the non-phase input terminal of the comparator is grounded through a first capacitor, the inverting input terminal of the comparator is connected to the power supply through a second resistor and to the ground through a third resistor, the output terminal of the comparator is connected to the base of the first transistor through a first diode, and the output terminal of the comparator is also connected to the light-emitting anode of the optocoupler through the first diode; the emitter of the first transistor is grounded, and the collector of the first transistor is connected to the drive signal output terminal of the MOSFET drive module; the voltage stored in the first capacitor is the voltage of the first resistor after being divided by the voltage divider circuit.

[0041] In the present application, the second resistor and the third resistor are used to provide a preset voltage threshold.

[0042] Furthermore, in one embodiment of the present invention, the locking unit is used to maintain the off state of the MOSFET or restart the MOSFET based on a locking signal; the locking signal is input into the base of the second transistor, the collector of the second transistor is connected to the power supply, the emitter of the second transistor is connected to the collector of the optocoupler, the emitter of the optocoupler is connected to the base of the first transistor, the emitter of the optocoupler is also connected to the light-emitting anode of the optocoupler, and the light-emitting cathode of the optocoupler is grounded.

[0043] Furthermore, in one embodiment of the present invention, the MOSFET functional module includes a push-pull output circuit, the push-pull output circuit includes a first MOSFET, a second MOSFET and a transformer, the transformer includes a first input winding and a second input winding; the gates of the first MOSFET and the second MOSFET are used to receive the drive signal of the MOSFET drive module, the sources of the first MOSFET and the second MOSFET are connected to the first resistor, the drain of the first MOSFET is connected to the first input end of the first input winding, the drain of the second MOSFET is connected to the second input end of the second input winding, and the second input end of the first input winding and the first input end of the second input winding are both connected to a power supply.

[0044] Furthermore, in one embodiment of the present invention, the driving signal of the MOSFET driving module includes a first PWM signal and a second PWM signal, and the level states of the first PWM signal and the second PWM signal are opposite;

[0045] The first PWM signal is input into the MOSFET functional module through a fourth resistor, and the second MOSFET functional module is input into the MOSFET functional module through a fifth resistor.

[0046] Furthermore, in one embodiment of the present invention, the resistance of the first resistor is 0.001 to 0.003 ohms.

[0047] On the other hand, the embodiment of the present invention provides a MOSFET short circuit protection and locking method, which is applied to the above-mentioned MOSFET short circuit protection and locking circuit, referring to Figure 3 In an embodiment of the present invention, a MOSFET short-circuit protection and locking method is provided. The MOSFET short-circuit protection and locking method in the embodiment of the present invention can be applied to a terminal, a server, or software running in a terminal or a server. The terminal can be a tablet computer, a laptop computer, a desktop computer, etc., but is not limited thereto. The server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The method includes:

[0048] Based on the MOSFET drive signal, drive the MOSFET to turn on or off to achieve the preset function;

[0049] A comparator compares a first voltage of a first resistor connected to the MOSFET with a preset voltage threshold, and according to a comparison result, turns off the MOSFET and maintains the MOSFET in the off state.

[0050] Furthermore, the MOSFET short-circuit protection and locking method according to an embodiment of the present invention further includes:

[0051] According to the comparison result, the MOSFET is turned off by the first transistor;

[0052] According to the comparison result, the MOSFET is kept in an off state through the optical coupler and the second transistor.

[0053] Furthermore, the MOSFET short-circuit protection and locking method according to an embodiment of the present invention further includes:

[0054] The MOSFET is restarted according to the received locking signal in the low level state.

[0055] It is understandable that after short-circuit protection and locking are performed, if the short-circuit condition is repaired, a low-level locking signal can be output through the control module to restart the MOSFET to work again.

[0056] It can be seen that the contents of the above circuit embodiments are all applicable to the present method embodiments. The functions specifically implemented by the present method embodiments are the same as those of the above circuit embodiments, and the beneficial effects achieved are also the same as those achieved by the above system embodiments.

[0057] Reference Figure 2 The following is a detailed introduction to the MOSFET short-circuit protection and locking circuit and method provided by the present application using a specific embodiment:

[0058] In response to the above-mentioned defects of the prior art, the short-circuit protection circuit and protection locking circuit designed in this application include a MOSFET driving circuit, a push-pull output circuit, and a protection action locking circuit.

[0059] The MOSFET drive circuit generates a PWM1 signal that is connected to the G-pole of the NPN MOSFET Q1 via resistors R1 (i.e., the fourth resistor), R2, and diode D1 (turn-on resistor). The PWM2 signal is connected to the G-pole of the MOSFET Q2 via resistors R3 (i.e., the fifth resistor), R4, and diode D2, and is used to normally turn Q1 and Q2 on and off. However, the PWM signals of the two are opposite.

[0060] The push-pull output circuit consists of a DC source, transformer T1, MOSFET Q1 (i.e., the first MOSFET), Q2 (i.e., the second MOSFET), MOSFET operating current sampling resistor Rcy (i.e., the first resistor), fast recovery diode D4, diode D5, inductor L1, and capacitor C1. The DC source is connected to pins 3, 4, and 5 of transformer T1. Pins 1 and 2 of T1 are connected to the drain D of MOSFET Q1. Pins 6 and 7 of T1 are connected to the D of Q2. Pin 12 of T1 is connected to diode D4, and pin 9 is connected to diode D5. The output is then filtered by inductor L1 and capacitor C1. Resistor Rcy is connected to the source S of MOSFETs Q1 and Q2. Its resistance is generally very low, exemplarily 0.001Ω.

[0061] The protection action and locking circuit consists of comparator U1, resistors R7 (i.e. the second resistor), R8 (i.e. the third resistor), diode D3 (i.e. the first diode), optocoupler U2, NPN transistors Q3 (i.e. the first transistor), Q4 (i.e. the second transistor), and bias resistors R10, R14, and current limiting resistors R11, R12, and R13 between the transistor base B and emitter E. The input V + The voltage stored in capacitor C2 (i.e., the first capacitor) is the sampling voltage V cy After the voltage is divided by R5 and R6, the input V - The set voltage threshold is connected to pin 2, output pin 1 is connected to pin 1 of optocoupler U2 through diode D3, and pin 2 of optocoupler is connected to ground; the on and off of transistor Q4 is controlled by mCtrl of the main control board (that is, the lock signal sent by the main control board); the base B of Q3 is connected to the output end of the comparator and pin 3 (secondary side) of the optocoupler, and the collector C of Q3 is connected to the drive input ends of Q1 and Q2.

[0062] about Figure 2 The working process of the provided circuit is as follows:

[0063] Under normal circumstances, the MOSFET drive circuit sends out PWM signals. Since the PWM1 and PWM2 signals are opposite, Q1 and Q2 are turned on and off in turn. When Q1 is normally turned on and Q2 is turned off, the DC source stores energy through coil 1 and then outputs it through coil 3. In addition, Q1's i ds From 0 to normal working current i ds(on) , since Rcy is only 0.001Ω, the voltage divided by R6 is much smaller than that in the short-circuit state under normal circumstances, that is, V + The voltage is far below the comparator threshold voltage, and the comparator normally outputs a low level. When Q2 is normally turned on and Q1 is turned off, the DC source stores energy through coil 2 and then outputs it through coil 4. This is the working mechanism of the push-pull output circuit under normal circumstances.

[0064] When a short circuit occurs at the output end, the primary coil inductance will drop to approximately zero. When any MOS tube Q1 or Q2 is turned on, the drain current I d It will rise sharply and flow through the sampling resistor Rcy to produce a large voltage drop. At this time, the voltage divider value on the resistor R6 When the set threshold voltage is exceeded, the comparator U1 outputs a high level. First, the transistor Q3 is turned on immediately, and the MOSFET drive is directly pulled down. In this way, Q1 and Q2 are turned off immediately, reducing the short-circuit withstand time. After Q1 and Q2 are turned off, there is no input V +, the comparator outputs a low level; secondly, the optocoupler can be turned on. The opening of Q4 is controlled by the mCtrl signal of the main control board. The default is a high level (that is, it is turned on by default). After the optocoupler is turned on, the base of Q3 is pulled high, that is, the comparator outputs a high level to turn on the transistor Q3, and the drive of Q1 and Q2 is pulled down. At the same time, it can also continue to drive the optocoupler, forming a protection lock. Only by pulling the mCtrl signal low through the main control board, Q4 is turned off, and the optocoupler is turned off, can the subsequent restart action be performed.

[0065] This application utilizes the characteristics of transistors and optocouplers to achieve self-locking protection, eliminating the need for a main control board for circuit protection and resulting in faster response. The release of the self-locking function is controlled by the main board, enhancing the reliability of the hardware protection. The overall circuit structure is simple and highly practical.

[0066] In some optional embodiments, the function / operation mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the function / operation involved, the two boxes shown in succession can actually be executed substantially simultaneously or the boxes can sometimes be executed in reverse order. In addition, the embodiment presented and described in the flow chart of the present invention is provided in an exemplary manner for the purpose of providing a more comprehensive understanding of the technology. The disclosed method is not limited to the operation and logic flow presented herein. Optional embodiments are contemplated in which the order of the various operations is changed and the sub-operations described as a part of a larger operation are performed independently.

[0067] In addition, although the present invention is described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in separate physical devices or software modules. It is also understood that a detailed discussion of the actual implementation of each module is not necessary for understanding the present invention. More specifically, given the properties, functions, and internal relationships of the various functional modules in the devices disclosed herein, the actual implementation of the module will be understood within the ordinary skill of an engineer. Therefore, a person skilled in the art will be able to implement the present invention set forth in the claims using ordinary skill without undue experimentation. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present invention, which is determined by the full scope of the appended claims and their equivalents.

[0068] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several programs for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0069] The logic and / or steps represented in a flowchart or otherwise described herein, for example, may be considered as an ordered list of executable programs for implementing the logical functions, and may be embodied in any computer-readable medium for use by, or in conjunction with, a program execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can retrieve and execute a program from a program execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" may be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, a program execution system, apparatus, or device.

[0070] More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0071] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable program execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0072] In the above description of this specification, reference to the terms "one embodiment / example," "another embodiment / example," or "certain embodiments / examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0073] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

[0074] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A MOSFET short-circuit protection and locking circuit, characterized in that: The circuit includes: a MOSFET driving module, a MOSFET functional module and a protection locking module; The MOSFET driving module is used to output a MOSFET driving signal to turn the MOSFET on or off; The MOSFET functional module realizes a preset function by turning on or off the MOSFET; the MOSFET functional module includes the MOSFET and a first resistor connected to the MOSFET, the first resistor being used to sample the operating current of the MOSFET; The protection locking module is used to compare the first voltage of the first resistor with a preset voltage threshold through a comparator, and according to the comparison result, turn off the MOSFET and keep the MOSFET in the off state.

2. The MOSFET short-circuit protection and lockout circuit according to claim 1, wherein: The protection locking module includes a protection unit and a locking unit; the protection unit includes a comparator and a first transistor, wherein the first transistor is used to receive the output signal of the comparator to turn off the MOSFET; the locking unit includes an optocoupler and a second transistor, wherein the optocoupler is used to receive the output signal of the comparator and, in combination with the second transistor, maintain the off state of the MOSFET.

3. The MOSFET short-circuit protection and lockout circuit according to claim 2, wherein: The protection unit also includes a first diode, a second resistor, and a third resistor; the non-inverting input of the comparator is grounded through a first capacitor, the inverting input of the comparator is connected to the power supply through a second resistor and to ground through a third resistor, the output of the comparator is connected to the base of the first transistor through a first diode, and the output of the comparator is also connected to the light-emitting anode of the optocoupler through the first diode; the emitter of the first transistor is grounded, and the collector of the first transistor is connected to the drive signal output of the MOSFET drive module; the voltage stored in the first capacitor is the voltage of the first resistor after being divided by a voltage divider circuit.

4. The MOSFET short-circuit protection and lockout circuit according to claim 2, wherein: The locking unit is used to maintain the off state of the MOSFET or restart the MOSFET based on a locking signal; the locking signal is input into the base of the second transistor, the collector of the second transistor is connected to the power supply, the emitter of the second transistor is connected to the collector of the optocoupler, the emitter of the optocoupler is connected to the base of the first transistor, the emitter of the optocoupler is also connected to the light-emitting anode of the optocoupler, and the light-emitting cathode of the optocoupler is grounded.

5. The MOSFET short-circuit protection and lockout circuit according to claim 1, wherein: The MOSFET functional module includes a push-pull output circuit, which includes a first MOSFET, a second MOSFET and a transformer, and the transformer includes a first input winding and a second input winding; the gates of the first MOSFET and the second MOSFET are used to receive the drive signal of the MOSFET drive module, the sources of the first MOSFET and the second MOSFET are connected to the first resistor, the drain of the first MOSFET is connected to the first input end of the first input winding, the drain of the second MOSFET is connected to the second input end of the second input winding, and the second input end of the first input winding and the first input end of the second input winding are both connected to a power supply.

6. The MOSFET short-circuit protection and lockout circuit according to claim 1, wherein: The driving signal of the MOSFET driving module includes a first PWM signal and a second PWM signal, and the level states of the first PWM signal and the second PWM signal are opposite; The first PWM signal is input into the MOSFET functional module through a fourth resistor, and the second MOSFET functional module is input into the MOSFET functional module through a fifth resistor.

7. The MOSFET short-circuit protection and lockout circuit according to claim 1, wherein: The resistance of the first resistor is: 0.001 to 0.003 ohms.

8. A MOSFET short-circuit protection and locking method, characterized in that: Applied to the MOSFET short-circuit protection and lockout circuit according to any one of claims 1 to 7, the method comprising: Based on the MOSFET drive signal, drive the MOSFET to turn on or off to achieve the preset function; A comparator compares a first voltage of a first resistor connected to the MOSFET with a preset voltage threshold, and according to a comparison result, turns off the MOSFET and maintains the MOSFET in the off state.

9. The MOSFET short-circuit protection and locking method according to claim 8, wherein: The method further comprises: According to the comparison result, the MOSFET is turned off by the first transistor; According to the comparison result, the MOSFET is kept in an off state through the optical coupler and the second transistor.

10. The MOSFET short-circuit protection and locking method according to claim 8, characterized in that: The method further includes: restarting the MOSFET according to the received locking signal in a low level state.

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