High voltage electronic switching circuit based on nmos transistors

Abstract

The application discloses a high-voltage electronic switch circuit based on NMOS tubes and relates to the technical field of electronics, which comprises a low-voltage side driving circuit, a high-voltage side basic driving circuit, a high-voltage side auxiliary driving circuit, a high-voltage side acceleration driving circuit and a low-edge electronic switch circuit. The low-voltage side driving circuit is used for converting a first switch control signal from the outside into a second switch control signal and a third switch control signal. The high-voltage side basic driving circuit is used for providing a first driving signal for the gate of all NMOS tubes in the low-edge electronic switch circuit under the control of the second switch control signal. The high-voltage side auxiliary driving circuit is used for providing a second driving signal for the high-voltage side acceleration driving circuit under the control of the third switch control signal. The high-voltage side acceleration driving circuit is used for accelerating the switching process of all NMOS tubes in the low-edge electronic switch circuit under the action of the second driving signal. The low-edge electronic switch circuit is used for realizing the switching control of the power supply for the load under the action of the first driving signal. The application can realize lower switching loss of the NMOS tube switching in the low-edge electronic switch circuit.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electronics, and particularly relates to a high-voltage electronic switch circuit based on an NMOS tube. BACKGROUND

[0002] In industrial and other direct-current high-voltage power supply occasions, a field effect tube is often used as an electronic switch to control the power-on and power-off of a direct-current power supply load. Compared with a relay, the field effect tube has obvious advantages as an electronic switch, such as small size, fast switching speed, and small conduction loss. An NMOS (N-channel Metal Oxide Semiconductor) is connected in series between the low side of a load and a high-voltage ground as a low-side electronic switch. The NMOS has the advantages of large power capacity and low conduction loss compared with a PMOS (P-channel Metal Oxide Semiconductor) tube, and has the advantage of a simple driving circuit. The NMOS is a commonly used electronic switch form.

[0003] However, if such a low-side NMOS electronic switch is driven by a switch tube driver similar to a switching power supply, an additional power supply circuit and driving chip are required, resulting in complex circuit design and high cost. If a simple biasing resistor is connected between the gate of the NMOS tube and the high-voltage power supply, and a voltage dividing resistor is connected between the gate of the NMOS tube and the high-voltage ground, the charging and discharging speed of the gate of the NMOS tube is greatly affected, resulting in slow discharging of the parasitic capacitance Ciss of the gate of the NMOS tube during switching, especially during switching-off, with a typical value of up to hundreds of microseconds. Combined with the high voltage and large current at the drain of the NMOS tube, the NMOS tube has large switching loss, generates a lot of heat, and is prone to damage during switching. SUMMARY

[0004] To solve the above problems in the prior art, the application provides a high-voltage electronic switch circuit based on an NMOS tube. The technical problem to be solved by the application is solved by the following technical scheme.

[0005] The application provides a high-voltage electronic switch circuit based on an NMOS tube, which comprises:

[0006] a low-side electronic switch circuit composed of one or more parallel NMOS tubes connected to the low side of a load;

[0007] a low-voltage side driving circuit for converting a first switch control signal from the outside into a second switch control signal and a third switch control signal under the power supply of a low-voltage power supply;

[0008] A high-voltage side basic drive circuit is configured to provide a first drive signal for the gate of all NMOS tubes in the low-side electronic switch circuit under the control of the second switch control signal and under the power supply of a high-voltage power supply.

[0009] A high-voltage side auxiliary drive circuit is configured to provide a second drive signal for the high-voltage side acceleration drive circuit under the control of the third switch control signal and under the power supply of the high-voltage power supply.

[0010] A high-voltage side acceleration drive circuit is configured to accelerate the switching process of all NMOS tubes in the low-side electronic switch circuit under the action of the second drive signal and under the power supply of the high-voltage power supply.

[0011] A low-side electronic switch circuit is configured to realize switching control of the power supply of the load under the action of the first drive signal.

[0012] The high-voltage side basic drive circuit and the high-voltage side auxiliary drive circuit each include an isolation optocoupler, thereby realizing the isolation of the first switch control signal on the low-voltage side from all high-voltage NMOS tubes in the low-side electronic switch circuit on the high-voltage side.

[0013] The present application has the following advantages:

[0014] The high-voltage electronic switch circuit based on NMOS tubes provided by the present application uses a single or multiple parallel NMOS tubes as a low-side electronic switch, and innovatively designs a multi-stage drive circuit including a low-voltage side drive circuit, a high-voltage side basic drive circuit, a high-voltage side auxiliary drive circuit, and a high-voltage side acceleration drive circuit, thereby accelerating the switching time of all NMOS tubes in the low-side electronic switch circuit, significantly improving the switching speed of the NMOS tubes in the low-side electronic switch circuit, especially the turn-off speed. Experiments have proved that the turn-off time of the NMOS tube is reduced to one-tenth of the original time under typical conditions, effectively solving the problems of large switching loss, serious heating of the NMOS tube, and easy damage of the NMOS tube caused by slow drop of the gate voltage during switching, especially during turn-off, of the existing low-side NMOS electronic switch, so that all NMOS tubes in the low-side electronic switch circuit have lower switching loss during switching. While realizing lower switching loss of all NMOS tubes in the low-side electronic switch circuit, the present application uses isolation optocouplers in the high-voltage side basic drive circuit and the high-voltage side auxiliary drive circuit, thereby further realizing the isolation of the switch control signal on the low-voltage side from all NMOS tubes in the low-side electronic switch circuit on the high-voltage side, reducing the interference of the high-voltage side circuit on the low-voltage side circuit, and making the overall circuit design more secure and reliable.

[0015] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic diagram of a high-voltage electronic switch circuit based on NMOS tubes provided by an embodiment of the present application;

[0017] Figure 2 is a specific circuit schematic diagram of a high-voltage electronic switch circuit based on NMOS tubes provided by an embodiment of the present application;

[0018] Figure 3 is a specific circuit schematic diagram of a high-voltage electronic switch circuit based on NMOS tubes provided by an embodiment of the present application, which only has a high-voltage side basic drive circuit. DETAILED DESCRIPTION

[0019] The present application will be further described in detail below in combination with specific embodiments, but the embodiments of the present application are not limited thereto.

[0020] Please refer to Figure 1 , the embodiment of the present application provides a high-voltage electronic switch circuit based on NMOS tubes, which comprises:

[0021] a low-side electronic switch circuit composed of one or more parallel NMOS tubes connected to a low side of a load;

[0022] a low-voltage side drive circuit for converting a first switch control signal from outside into a second switch control signal and a third switch control signal under the power supply of a low-voltage power supply;

[0023] a high-voltage side basic drive circuit for providing a first drive signal for the gate of all NMOS tubes in the low-side electronic switch circuit under the control of the second switch control signal under the power supply of a high-voltage power supply;

[0024] a high-voltage side auxiliary drive circuit for providing a second drive signal for the high-voltage side acceleration drive circuit under the control of the third switch control signal under the power supply of a high-voltage power supply;

[0025] a high-voltage side acceleration drive circuit for accelerating the switching process of all NMOS tubes in the low-side electronic switch circuit under the action of the second drive signal under the power supply of a high-voltage power supply;

[0026] a low-side electronic switch circuit for realizing the switching control of the power supply of a load under the action of the first drive signal;

[0027] Among them, the high-voltage side basic drive circuit and the high-voltage side auxiliary drive circuit respectively include an isolation optocoupler, which realizes the isolation of the first switch control signal from outside of the low-voltage side and all NMOS tubes in the low-side electronic switch circuit located at the high-voltage side.

[0028] The source of all NMOS tubes in the low-side electronic switch circuit is connected to a high-voltage ground; one end of a load is connected to a positive pole of a high-voltage power supply, the other end of the load is connected to the drain of all NMOS tubes in the low-side electronic switch circuit, and the negative pole of the high-voltage power supply is connected to a high-voltage ground.

[0029] The high-voltage electronic switch circuit based on NMOS tubes provided by the embodiment of the application uses a single or multiple parallel NMOS tubes as a low-side electronic switch, and a multi-stage driving circuit including a low-voltage side driving circuit, a high-voltage side basic driving circuit, a high-voltage side auxiliary driving circuit and a high-voltage side acceleration driving circuit is innovatively designed to solve the problems of the existing low-side NMOS electronic switch, the multi-stage driving accelerates the switching time of all NMOS tubes in the low-side electronic switch circuit, significantly improves the switching speed of the NMOS tubes in the low-side electronic switch circuit, especially the turn-off speed, and experiments prove that the turn-off time of the NMOS tube is reduced to one tenth of the original time under typical conditions, effectively solving the problems of large switching loss, serious heating and easy damage of the NMOS tube caused by slow drop of the gate voltage during switching, especially turn-off, of the existing low-side NMOS electronic switch, so that all NMOS tubes in the low-side electronic switch circuit have lower switching loss during switching. While realizing lower switching loss of all NMOS tubes in the low-side electronic switch circuit, the isolation optocoupler is used in the high-voltage side basic driving circuit and the high-voltage side auxiliary driving circuit in the embodiment of the application, which further realizes the isolation of the low-voltage side switching control signal and all NMOS tubes in the low-side electronic switch circuit located on the high-voltage side, reduces the interference of the high-voltage side circuit on the low-voltage side circuit, and makes the overall circuit design have higher safety and reliability.

[0030] Next, the circuit design of each part is introduced in detail.

[0031] The low-side electronic switch circuit in the embodiment of the application is shown in Figure 2 The gate of the NMOS tube Q3 is connected to the high-voltage side basic driving circuit, the drain of the NMOS tube Q3 is connected to the load, and the source of the NMOS tube Q3 is connected to a high-voltage ground.

[0032] The low-side electronic switch circuit in the embodiment of the application can also include multiple parallel NMOS tubes Q3; the gates of all NMOS tubes Q3 are connected to the high-voltage side basic driving circuit, the drains of all NMOS tubes Q3 are connected to the load, and the sources of all NMOS tubes Q3 are connected to a high-voltage ground. Using multiple parallel NMOS tubes Q3 can improve the power capacity of the circuit.

[0033] The low-voltage side driving circuit in the embodiment of the application is shown in Figure 2As shown, it includes a resistor R1, a resistor R2, and a transistor Q1; wherein one end of the resistor R1 serves as the input end of the first switch control signal, the other end of the resistor R1 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is connected to the low-voltage ground, and the collector of the transistor Q1 is connected to the high-side auxiliary drive circuit. One end of the resistor R2 is connected to the positive electrode of the low-voltage power supply, and the other end of the resistor R2 is connected to the high-side basic drive circuit, and the negative electrode of the low-voltage power supply is connected to the low-voltage ground. Through this low-voltage side drive circuit, the first switch control signal from the outside is converted into a second switch control signal and a third switch control signal under the power supply of the low-voltage power supply. When the first switch control signal is at a high level, it indicates that the electronic switch is on, and when the first switch control signal is at a low level, it indicates that the electronic switch is off.

[0034] The basic driving circuit on the high-voltage side in the embodiment of the present invention is as follows Figure 2 As shown, it includes an isolation optocoupler U1, resistors R3 and R4, and capacitor C1. The anode of the diode on the primary side of the isolation optocoupler U1 is connected to the low-voltage side drive circuit, the cathode of the diode on the primary side of the isolation optocoupler U1 is connected to the high-voltage side auxiliary drive circuit, the collector on the secondary side of the isolation optocoupler U1 is connected to one end of the resistor R3, and the emitter on the secondary side of the isolation optocoupler U1 is connected to one end of the resistor R4, one end of the capacitor C1, the high-side acceleration drive circuit, and the gates of all NMOS transistors in the low-side electronic switch circuit. The other end of the resistor R3 is connected to the positive electrode of the high-voltage power supply, and the negative electrode of the high-voltage power supply, the other end of the resistor R4, and the other end of the capacitor C1 are all connected to the high-voltage ground. Through this high-side basic drive circuit, a first drive signal is provided to the gates of all NMOS transistors in the low-side electronic switch circuit under the power supply of the high-voltage power supply and the control of the second switch control signal.

[0035] Here, the function of capacitor C1 is to eliminate the influence of interference signal on the gate of NMOS tube Q3 during operation, but its existence is not conducive to speeding up the switching speed of NMOS tube Q3. Figure 2 The high-voltage electronic switch circuit, which is composed of a low-side electronic switch circuit, a low-voltage side drive circuit, and a high-voltage side basic drive circuit, has a basic switching function, but the switching speed of the NMOS tube Q3 is very slow, and the NMOS tube Q3 still has problems such as large switching loss, severe heating of the NMOS tube, and easy damage. To this end, the embodiment of the present invention further improves the circuit design on the basis of the high-voltage electronic switch circuit composed of a low-side electronic switch circuit, a low-voltage side drive circuit, and a high-voltage side basic drive circuit in order to speed up the switching speed of the NMOS tube Q3. By adding a high-voltage side auxiliary drive circuit and a high-voltage side acceleration drive circuit, a multi-stage drive structure is formed with the high-voltage side basic drive circuit to achieve the above purpose. Specifically:

[0036] The high-voltage side auxiliary drive circuit in the embodiment of the present invention is as follows Figure 2 As shown, it includes an isolation optocoupler U2, a resistor R5, and a resistor R6; wherein the anode of the diode on the primary side of the isolation optocoupler U2 is connected to the high-voltage side basic drive circuit, the cathode of the diode on the primary side of the isolation optocoupler U2 is connected to the low-voltage side drive circuit, the collector on the secondary side of the isolation optocoupler U2 is connected to one end of the resistor R5, one end of the resistor R6, and the high-voltage side acceleration drive circuit, the emitter on the secondary side of the isolation optocoupler U2 and the other end of the resistor R5 are both connected to the high-voltage ground, the other end of the resistor R6 is connected to the positive electrode of the high-voltage power supply, and the negative electrode of the high-voltage power supply is connected to the high-voltage ground. Through this high-voltage side auxiliary drive circuit, a second drive signal is provided to the high-voltage side acceleration drive circuit under the power supply of the high-voltage power supply and the control of the third switch control signal.

[0037] The high-voltage side acceleration drive circuit in the embodiment of the present invention is as follows Figure 2 As shown, it includes an NMOS transistor Q2, a resistor R7, a resistor R8, a diode D1, and a diode D2; wherein the gate of the NMOS transistor Q2 is connected to the high-voltage side auxiliary drive circuit, the source of the NMOS transistor Q2 is connected to the high-voltage ground, the drain of the NMOS transistor Q2 is connected to one end of the resistor R7, one end of the resistor R8, the anode of the diode D1, and the cathode of the diode D2, the other end of the resistor R7 is connected to the high-voltage ground, the other end of the resistor R8 is connected to the positive electrode of the high-voltage power supply, and the cathode of the diode D1 is connected to the anode of the diode D2 and the high-voltage side basic drive circuit. Through this high-voltage side acceleration drive circuit, the switching process of all NMOS transistors in the high-voltage side basic drive circuit is accelerated under the power supply of the high-voltage power supply and the action of the second drive signal.

[0038] The anti-parallel diodes D1 and D2 in the high-side acceleration drive circuit of the embodiment of the present invention are necessary. They can ensure that the drain of the NMOS transistor Q2 and the gate of the NMOS transistor Q3 are both isolated and clamped to each other, which helps protect the gate of the NMOS transistor Q3 from damage caused by the instantaneous high voltage during shutdown.

[0039] The resistance ratio of the resistor R7 to the resistor R8 in the high-side acceleration drive circuit of the embodiment of the present invention is the same as the resistance ratio of the resistor R4 to the resistor R3 in the high-side basic drive circuit.

[0040] Ultimately, the embodiment of the present invention can significantly improve the switching speed of all NMOS transistors in the low-side electronic switch circuit through the design of a multi-stage drive circuit. While achieving lower switching losses, it also achieves isolation between the switch control signal on the low-voltage side and all NMOS transistors in the low-side electronic switch circuit on the high-voltage side. At the same time, the embodiment of the present invention is designed using low-cost and easily available discrete components, using a single or multiple parallel NMOS transistors as the low-side electronic switch circuit. While maintaining a simple circuit structure and using only discrete components, it can still effectively improve the switching speed of all NMOS transistors in the low-side electronic switch circuit, especially the shutdown speed.

[0041] Figure 3 The diagram shows a high-voltage electronic switch circuit with only a basic high-voltage side drive circuit. Its working principle is: when an appropriate current passes through the diode in the primary side of the isolation optocoupler U1, the secondary side of the isolation optocoupler U1 is turned on, and the high voltage from the high-voltage power supply passes through the resistor R3 and the secondary side of the isolation optocoupler U1 to form a voltage divider with the resistor R4. Due to the presence of the parasitic capacitance Ciss of the capacitor C1 and the gate of the NMOS tube Q3, when the capacitor C1 or the parasitic capacitance Ciss is in the charging process, the voltage on the resistor R4 gradually increases from 0 to the voltage of the voltage dividing point between the resistor R3 and the resistor R4. This process is the turn-on time of the NMOS tube Q3. Obviously, this turn-on time is the charging time after the capacitor C1 and the parasitic capacitance Ciss are connected in parallel. The larger the charging current, the shorter the charging time. When the high-voltage power supply's voltage is constant, the charging time is determined by the resistance of resistor R3. The smaller the resistance, the greater the charging current. When the diode current in the primary side of the isolating optocoupler U1 disappears, the secondary side of the isolating optocoupler U1 is turned off, and resistor R3 is disconnected from the circuit. The voltage resulting from the parallel connection of capacitor C1 and parasitic capacitance Ciss is discharged only through resistor R4. Obviously, the time it takes for the voltage on resistor R4 to drop from the voltage at the voltage divider between resistors R3 and R4 to zero is the turn-off time of the NMOS transistor Q1. The greater the discharge current, the shorter the turn-off time. The smaller the resistor R4, the greater the discharge current. If the resistance of resistor R4 is 0, the turn-off can be completed instantly. However, resistor R4 cannot be 0, otherwise it will not play a voltage divider role. However, it cannot be too small, otherwise, to maintain the voltage divider ratio, the resistance of resistor R3 must also be small, which will increase the power consumption of resistors R3 and R4 during the conduction period of the NMOS transistor Q3. Therefore, the key to reducing the turn-on and turn-off time of the NMOS tube Q3 is how to increase the charge and discharge current of the capacitor C1 and the parasitic capacitor Ciss in parallel. Figure 3 Based on this, we designed Figure 2 The complete high-voltage electronic switching circuit is shown.

[0042] Combine Figure 2 and Figure 3 The working principle of the complete high-voltage electronic switch circuit of the present invention is as follows:

[0043] Firstly, the opening acceleration principle of the electronic switch is described.

[0044] When the resistor R1 receives a high level signal representing the opening of the electronic switch, the transistor Q1 is turned on, and the low voltage signal from the low voltage power supply is transmitted to the low voltage ground through the resistor R2, the diode in the primary side of the isolation optocoupler U1, the diode in the primary side of the isolation optocoupler U2, the transistor Q1, thereby simultaneously opening the isolation optocoupler U1 and the isolation optocoupler U2. The secondary side of the isolation optocoupler U2 shorts the resistor R5, so that the voltage at the gate of the NMOS tube Q2 is 0, and the NMOS tube Q2 is in the off state. The resistor R7 is not shorted, and the high voltage from the high voltage power supply passes through the resistor R8 and charges the capacitor C1 and the parasitic capacitance Ciss at the gate of the NMOS tube Q3 through the diode D1. At the same time, since the secondary side of the isolation optocoupler U1 is turned on, the high voltage signal from the high voltage power supply also charges the capacitor C1 and the parasitic capacitance Ciss at the gate of the NMOS tube Q3 through the resistor R3, thereby accelerating the capacitor charging process. Since the resistance ratio of the resistor R7 and the resistor R8 is the same as the resistance ratio of the resistor R4 and the resistor R3, the voltage across the diode D1 after being fully charged is close in value. After being fully charged, the NMOS tube Q3 is fully turned on, and the load starts to work.

[0045] Next, the closing acceleration principle of the electronic switch is described.

[0046] When the resistor R1 receives a low level signal representing the closing of the electronic switch, the transistor Q1 is turned off, and the isolation optocoupler U1 and the isolation optocoupler U2 are also simultaneously turned off, and the secondary sides of the two are not conductive. The short-circuit state of the resistor R5 disappears, and the high voltage signal from the high voltage power supply is sufficient to open the NMOS tube Q2 through the voltage divided by the resistor R6 and the resistor R5. The NMOS tube Q2 also has its own parasitic capacitance Ciss, but generally the parasitic capacitance Ciss is much smaller than the parallel capacitance of the parasitic capacitance Ciss at the gate of the NMOS tube Q3 and the capacitor C1. As long as the resistance of the resistor R6 and the resistor R5 is properly selected, the opening time of the NMOS tube Q2 can be ignored compared with the closing time of the NMOS tube Q3. The opened NMOS tube Q2 shorts the resistor R7 to the high voltage ground. At this time, the charges stored in the parallel capacitor C1 and the parasitic capacitance Ciss at the gate of the NMOS tube Q3 are directly discharged to the high voltage ground through the diode D2 without passing through the resistor R4, so the discharge speed is extremely fast, and the NMOS tube Q3 quickly completes the closing, and the load stops working.

[0047] In the description of the application, it should be understood that the terms "first", "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0048] Although the application is described herein in conjunction with various embodiments, those skilled in the art, by referring to the description and drawings, can understand and implement other changes of the disclosed embodiments in the implementation of the claimed application. In the description, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude a plurality. Some measures are described in mutually different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0049] The above is a further detailed description of the application in conjunction with specific preferred embodiments, and cannot be considered as limiting the specific implementation of the application to these descriptions. For those skilled in the art, without departing from the concept of the application, a number of simple deductions or substitutions can be made, which should be considered as falling within the protection scope of the application.

Claims

1. A high-voltage electronic switching circuit based on an NMOS tube, characterized in that: The high-voltage electronic switching circuit comprises: The low-side electronic switch circuit consists of one or more parallel NMOS tubes connected to the low side of the load; A low-voltage side driving circuit, configured to convert a first switch control signal from an external source into a second switch control signal and a third switch control signal when powered by a low-voltage power supply; a high-side basic driving circuit, configured to provide a first driving signal to the gates of all NMOS transistors in the low-side electronic switch circuit under the power supply of a high-voltage power supply and under the control of the second switch control signal; a high-voltage side auxiliary driving circuit, configured to provide a second driving signal to the high-voltage side acceleration driving circuit under the power supply of a high-voltage power supply and under the control of the third switch control signal; a high-side acceleration driving circuit, configured to accelerate the switching process of all NMOS transistors in the low-side electronic switch circuit under the power supply of a high-voltage power supply and under the action of the second driving signal; a low-side electronic switching circuit, configured to implement on-off control of power supply to a load under the action of the first drive signal; The high-side basic drive circuit and the high-side auxiliary drive circuit each include an isolation optocoupler to isolate the first switch control signal outside the low-voltage side from all NMOS transistors in the low-side electronic switch circuit on the high-voltage side. The high-side acceleration drive circuit includes an NMOS transistor Q2, a resistor R7, a resistor R8, a diode D1, and a diode D2; wherein the gate of the NMOS transistor Q2 is connected to the high-side auxiliary drive circuit, the source of the NMOS transistor Q2 is connected to the high-voltage ground, the drain of the NMOS transistor Q2 is connected to one end of the resistor R7, one end of the resistor R8, the anode of the diode D1, and the cathode of the diode D2, the other end of the resistor R7 is connected to the high-voltage ground, the other end of the resistor R8 is connected to the positive electrode of the high-voltage power supply, and the cathode of the diode D1 is connected to the anode of the diode D2 and the high-voltage side basic drive circuit.

2. The high-voltage electronic switch circuit based on an NMOS tube according to claim 1, characterized in that: The low-voltage side driving circuit includes a resistor R1, a resistor R2, and a transistor Q1; wherein, One end of the resistor R1 serves as the input end of the first switch control signal, the other end of the resistor R1 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is connected to the low-voltage ground, the collector of the transistor Q1 is connected to the high-voltage side auxiliary drive circuit, one end of the resistor R2 is connected to the positive electrode of the low-voltage power supply, the other end of the resistor R2 is connected to the high-voltage side basic drive circuit, and the negative electrode of the low-voltage power supply is connected to the low-voltage ground.

3. The high-voltage electronic switch circuit based on NMOS tube according to claim 1, characterized in that: The high-voltage side basic driving circuit includes an isolation optocoupler U1, a resistor R3, a resistor R4 and a capacitor C1; wherein, The anode of the diode in the primary side of the isolation optocoupler U1 is connected to the low-voltage side drive circuit, the cathode of the diode in the primary side of the isolation optocoupler U1 is connected to the high-voltage side auxiliary drive circuit, the collector in the secondary side of the isolation optocoupler U1 is connected to one end of the resistor R3, the emitter in the secondary side of the isolation optocoupler U1 is connected to one end of the resistor R4, one end of the capacitor C1, the high-voltage side acceleration drive circuit, and the gates of all NMOS tubes in the low-side electronic switch circuit, the other end of the resistor R3 is connected to the positive electrode of the high-voltage power supply, and the negative electrode of the high-voltage power supply, the other end of the resistor R4, and the other end of the capacitor C1 are all connected to the high-voltage ground.

4. The high-voltage electronic switch circuit based on an NMOS tube according to claim 1, characterized in that: The high-voltage side auxiliary driving circuit includes an isolation optocoupler U2, a resistor R5, and a resistor R6; wherein, The anode of the diode in the primary side of the isolation optocoupler U2 is connected to the high-voltage side basic drive circuit, the cathode of the diode in the primary side of the isolation optocoupler U2 is connected to the low-voltage side drive circuit, the collector in the secondary side of the isolation optocoupler U2 is connected to one end of the resistor R5, one end of the resistor R6, and the high-voltage side acceleration drive circuit, the emitter in the secondary side of the isolation optocoupler U2 and the other end of the resistor R5 are both connected to the high-voltage ground, the other end of the resistor R6 is connected to the positive pole of the high-voltage power supply, and the negative pole of the high-voltage power supply is connected to the high-voltage ground.

5. The high-voltage electronic switch circuit based on NMOS tube according to claim 3, characterized in that: The resistance ratio of the resistor R7 to the resistor R8 in the high-voltage side acceleration drive circuit is the same as the resistance ratio of the resistor R4 to the resistor R3 in the high-voltage side basic drive circuit.

6. The high-voltage electronic switch circuit based on an NMOS tube according to claim 1, characterized in that: The low-side electronic switch circuit includes an NMOS transistor Q3; the gate of the NMOS transistor Q3 is connected to the high-voltage side basic drive circuit, the drain of the NMOS transistor Q3 is connected to the load, and the source of the NMOS transistor Q3 is connected to the high-voltage ground.

7. The high-voltage electronic switch circuit based on an NMOS tube according to claim 1, characterized in that: The low-side electronic switch circuit includes a plurality of NMOS transistors Q3 connected in parallel; the gates of all NMOS transistors Q3 are connected to the high-voltage side basic drive circuit, the drains of all NMOS transistors Q3 are connected to the load, and the sources of all NMOS transistors Q3 are connected to the high-voltage ground.

8. The high-voltage electronic switch circuit based on an NMOS tube according to claim 1, characterized in that: One end of the load is connected to the positive electrode of the high-voltage power supply, the other end of the load is connected to the low-side electronic switch circuit, and the negative electrode of the high-voltage power supply is connected to the high-voltage ground.

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