NMOS Switch Driving Circuit and Power Supply Device

Abstract

Improves the operational stability of the circuit. [Solution] The present invention discloses an NMOS switch driving circuit, in which a power supply unit is used to output a first voltage. The switch unit is electrically connected between the power supply unit and a first interface and is used to establish or disconnect the electrical connection between the power supply unit and the first interface, and the switch unit includes at least one NMOS switch. One end of the power conversion unit is connected to the power supply unit, and the other end of the power conversion unit is electrically connected to the switch unit via the driving unit. The power conversion unit converts the first voltage into a constant driving voltage and outputs it to the switch unit via the driving unit to drive the switch unit to conduct, thereby establishing the electrical connection between the power supply unit and the first interface.

Description

Technical Field

[0001] The present invention relates to the field of circuit technology, and more particularly, to an NMOS switch driving circuit and a power supply device.

Background Art

[0002] With the development of microelectronics technology, N-channel MOSFETs have shown increasingly remarkable advantages in high-frequency, high-power, and high-efficiency switching applications compared to triodes and P-channel MOSFETs. According to its device characteristics, when a high-voltage signal is applied to the gate of an N-channel MOSFET relative to the source, the drain and source of the N-channel MOSFET can be effectively controlled to turn on. When the gate voltage of the N-channel MOSFET is set to follow the source voltage, the drain and source of the N-channel MOSFET can be effectively controlled to turn off.

[0003] In existing NMOS switch driving circuits, the NMOS switch is connected between a power supply and a load. When the voltage of the power supply fluctuates up and down, the driving voltage of the NMOS switch also experiences a wide voltage drop fluctuation of dropping or rising. Therefore, there is a possibility that the driving voltage cannot reach the conduction condition of the NMOS switch. When the NMOS switch is in a semi-conducted state (i.e., operating in the linear region), the internal resistance increases, the heat generation of the NMOS switch is serious, or the driving voltage exceeds the gate-source breakdown voltage of the NMOS switch, leading to breakdown, short circuit, or burnout of the NMOS switch.

Summary of the Invention

[0004] Embodiments of the present invention disclose an NMOS switch driving circuit and a power supply device, which can ensure the normal driving of the NMOS switch by providing a stable driving voltage, thereby extending the life of the NMOS switch and improving the operating stability of the NMOS switch driving circuit.

[0005] In a first aspect, the NMOS switch driving circuit according to an embodiment of the present invention is applied to a power supply device having a first interface and a second interface. The NMOS switch driving circuit includes a power supply unit, a switch unit, a power conversion unit, and a driving unit. The power supply unit is used to output a first voltage. The switch unit is electrically connected between the power supply unit and the first interface and is used to establish or disconnect the electrical connection between the power supply unit and the first interface. The switch unit includes at least one NMOS switch. One end of the power conversion unit is connected to the power supply unit, and the other end of the power conversion unit is electrically connected to the switch unit via the driving unit. The power conversion unit is used to convert the first voltage into a constant driving voltage and output it to the switch unit via the driving unit to drive the switch unit to conduct and establish the electrical connection between the power supply unit and the first interface.

[0006] In a second aspect, a power supply device according to an embodiment of the present invention includes a first interface and a second interface and further includes the NMOS switch driving circuit described in the first aspect. The NMOS switch driving circuit is connected to a load via the first interface and the second interface.

[0007] Since the NMOS switch driving circuit and the power supply device of the present invention include a power conversion unit that converts the first voltage into a constant driving voltage and then outputs it to the switch unit, even if the first voltage fluctuates up and down, the NMOS switch can still receive a stable driving voltage, is not affected by the fluctuation of the first voltage output from the front-end power supply unit, thus ensuring the effective driving of the switch unit, extending the service life of the switch unit, improving the operating stability of the NMOS switch driving circuit, preventing breakdown damage of the switch unit caused by an excessively high driving voltage, or preventing serious heat generation of the switch unit caused by an excessively low driving voltage.

Brief Description of the Drawings

[0008] The following briefly describes the drawings used in the description of the embodiments of the present invention in order to more clearly explain the technical solutions of the embodiments of the present invention. Obviously, the drawings described below are only those of some embodiments of the present invention, and those skilled in the art can obtain other drawings without creative efforts from these drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0009] The following clearly and completely describes the technical means of the embodiments of the present invention with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments that can be obtained by those skilled in the art without creative efforts from the embodiments described in this specification shall fall within the scope of the present invention.

[0010] When an element is considered to be "connected" to another element, that element is either directly connected to the other element or there may also be intermediate elements present. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the technical field of the present invention. The terms used in the description of the present invention in this specification are not intended to limit the present invention, but rather to describe specific embodiments.

[0011] This application provides a power supply device and an NMOS switch driving circuit applied to the power supply device. The NMOS switch driving circuit is connected to a load, and when the NMOS switch is in the on state, the power supply device can supply power to the load. The NMOS switch driving circuit according to the embodiment of the present application can improve the stability of the operation process of the NMOS switch driving circuit. Hereinafter, the embodiments of the present application will be introduced with reference to the drawings.

[0012] Referring to FIG. 1, an embodiment of the present invention provides a power supply device 300. The power supply device 300 is connected to a load 200 and is used to supply power to the load 200. Specifically, the power supply device 300 includes an NMOS switch driving circuit 100 and is provided with a first interface N1 and a second interface N2. The NMOS switch driving circuit 100 is connected to the load 200 via the first interface N1 and the second interface N2. Here, the first interface N1 and the second interface N2 can exist in the form of wiring terminals, and the specific implementation manner is not limited.

[0013] In the embodiment of the present application, the power supply device 300 can be an emergency starting power supply, and the load 200 can be a battery (accumulator) in a vehicle. Since the battery of the vehicle is connected to the engine of the vehicle, after the emergency starting power supply is connected to the battery of the vehicle, the two can together provide a starting current to the engine of the vehicle to start the vehicle emergently. In other embodiments, the power supply device 300 can be other types of power supplies (such as a power supply for power tools), which is not limited.

[0014] Referring to FIG. 2, it is a principle block diagram of the NMOS switch driving circuit 100 according to an embodiment of the present application. The NMOS switch driving circuit 100 includes a power supply unit 10, a switch unit 20, a power conversion unit 30, and a driving unit 40.

[0015] The power supply unit 10 is used to output a first voltage. In one embodiment, the power supply unit 10 can include a battery pack (not shown). Specifically, the battery pack can include one or more battery modules connected to each other, and each battery module can include at least one battery cell (single battery). For example, the battery cell is a lightweight, energy-saving, and environmentally friendly lithium-ion battery cell. In a specific embodiment, a plurality of battery modules can be combined in series and parallel to provide the output voltage and output current of the power supply unit 10. It can be understood that the first voltage changes with the use of the power supply unit 10 or at the start of the load 200.

[0016] The switch unit 20 is electrically connected between the power supply unit 10 and the first interface N1 and includes at least one NMOS switch. The switch unit 20 is used to establish or disconnect the electrical connection between the power supply unit 10 and the first interface N1. In this embodiment, the first interface N1 is a positive electrode interface. The switch unit 20 is connected between the positive electrode of the power supply unit 10 and the first interface N1. The second interface N2 is a negative electrode interface, and the negative electrode of the power supply unit 10 is connected to the second interface N2.

[0017] One end of the power conversion unit 30 is connected to the power unit 10, and the other end of the power conversion unit 30 is electrically connected to the switch unit 20 via the drive unit 40. The power conversion unit 40 receives the first voltage output from the power unit 10, converts the first voltage into a constant drive voltage, and then outputs it to the switch unit 20 via the drive unit 30 to drive the switch unit 20 to conduct.

[0018] Since the NMOS switch driving circuit 100 disclosed in the embodiment of the present application includes a power conversion unit 30 that converts the first voltage into a constant drive voltage and then outputs it to the switch unit 20, even if the first voltage fluctuates up and down, the NMOS switch still receives a stable drive voltage and is not affected by the fluctuation of the first voltage output from the front-end power unit 10. Therefore, the effective drive of the switch unit 20 is ensured, the service life of the switch unit 20 is extended, the operating stability of the NMOS switch driving circuit 100 is improved, the breakdown damage of the switch unit 20 caused by an excessively high drive voltage is prevented, or the serious heat generation of the switch unit 20 caused by an excessively low drive voltage is prevented.

[0019] Since the power supply device 300 provided by the embodiment of the present application employs the above-described NMOS switch driving circuit 100, it can provide a stable operating voltage to the load 200 and improve the performance and quality of the power supply device 300.

[0020] In one embodiment, in order to achieve effective control over the switch unit 20, the NMOS switch driving circuit 100 further includes a control unit 50. The control unit 50 is electrically connected to the power conversion unit 30 and the driving unit 40 respectively. The control unit 50 is used to output a conversion signal to the power conversion unit 30 and a driving signal to the driving unit 40. The power conversion unit 30 converts a first voltage into a driving voltage according to the conversion signal. The driving unit 40 outputs the driving voltage to the switch unit 20 according to the driving signal to drive the switch unit 20 to conduct. Among them, the conversion signal can be a high-level signal or a low-level signal, and the driving signal can be a high-level signal or a low-level signal, which is not limited here.

[0021] In this embodiment, the control unit 50 can be a single-chip microcomputer. The control unit 50 can include a plurality of signal acquisition ports, communication ports, a plurality of control ports, etc.

[0022] Referring to FIG. 3, in another embodiment, different from the above embodiment (FIG. 2), the NMOS switch driving circuit 100 further includes a current detection unit 60. The current detection unit 60 is electrically connected between the negative electrode of the power supply unit 10 and the second interface N2 and is used to detect the output current of the power supply unit 10. The control unit 50 is electrically connected to the current detection unit 60 and collects the current signal detected by the current detection unit 60. When the current signal collected by the control unit 50 is greater than a preset threshold, the control unit 50 stops outputting the conversion signal and / or the driving signal.

[0023] When the current signal detected by the current detection unit 60 is greater than a preset threshold value, it indicates that the system has a fault or a short circuit. At this time, the electrical connection between the power supply unit 10 and the load 200 should be disconnected, so that the switch unit 20 and the load 200 can be protected, and the service life of the switch unit 20 and the load 200 can be extended.

[0024] Referring to FIG. 4, it is a circuit schematic diagram of the NMOS switch driving circuit 100 according to the embodiment of the present application. As shown in FIG. 4, the switch unit 20 includes a first NMOS field effect transistor Q1, a second NMOS field effect transistor Q2, and first to third resistors R1 to R3. The gate of the first NMOS field effect transistor Q1 is connected to the driving unit 40 via the first resistor R1, the drain of the first NMOS field effect transistor Q1 is connected to the positive electrode of the power supply unit 10, and the source of the first NMOS field effect transistor Q1 is connected to the reference zero point DR-GND and is also connected to the driving unit 40 via the second resistor R2. The gate of the second NMOS field effect transistor Q2 is connected to the driving unit 40 via the third resistor R3, the source of the second NMOS field effect transistor Q2 is connected to the reference zero point DR-GND and is also connected to the driving unit 40 via the second resistor R2, and the drain of the second NMOS field effect transistor Q2 is connected to the first interface N1.

[0025] The reference zero point DR-GND is relative to the driving voltage of the NMOS driving switch and is not the actual "ground". For example, the voltage of the reference zero point can be 1V, 2V or others. In this embodiment, when the first NMOS field effect transistor Q1 is not turned on, the potential of the reference zero point DR-GND is 0, and when the first NMOS field effect transistor Q1 is turned on, the potential of the reference zero point DR-GND is the output voltage of the power supply unit 10.

[0026] In other embodiments, in order to improve the overcurrent capacity of the switch unit 20, it should be understood that the switch unit 20 can include a plurality of groups of first NMOS field effect transistors Q1 and second NMOS field effect transistors Q2 connected in parallel, and the specific quantity is not limited. Of course, in some embodiments, the switch unit 20 can also include only one NMOS field effect transistor.

[0027] The power conversion unit 30 includes a first electronic switch T1, a second electronic switch T2, a conversion power supply U1, a fourth resistor R4, and a fifth resistor R5. The control end of the first electronic switch T1 is connected to the control unit 50, the first connection end of the first electronic switch T1 is connected to the negative electrode of the power supply unit 10, and the second connection end of the first electronic switch T1 is connected to the control end of the second electronic switch T2 via the fourth resistor R4. The first connection end of the second electronic switch T2 is connected to the positive electrode of the power supply unit 10, the second connection end of the second electronic switch T2 is connected to the first input end of the conversion power supply U1, and the control end of the second electronic switch T2 is further connected to the first connection end of the second electronic switch T2 via the fifth resistor R5. The second input end of the conversion power supply U1 is connected to the negative electrode of the power supply unit 10, the first output end of the conversion power supply U1 is connected to the drive unit 40, and the second output end of the conversion power supply U1 is connected to the reference zero point DR-GND.

[0028] The conversion power supply U1 is a stabilized power supply with a wide input range and can convert a fluctuating input voltage into a stable output voltage. For example, the conversion power supply U1 can be a DC-DC converter and can implement functions such as Boost step-up, Buck step-down, Boost-Buck step-up and step-down, and bootstrap conversion.

[0029] In this embodiment, the first electronic switch T1 is an NPN transistor. The control terminal, the first connection terminal, and the second connection terminal of the first electronic switch T1 correspond to the base, the emitter, and the collector of the NPN transistor, respectively. In this embodiment, the bias resistor is integrated into the NPN transistor.

[0030] The second electronic switch T2 is a PMOS field-effect transistor. The control terminal, the first connection terminal, and the second connection terminal of the second electronic switch T2 correspond to the gate, the source, and the drain of the PMOS field-effect transistor, respectively. In this embodiment, the PMOS field-effect transistor has a parasitic diode.

[0031] The driving unit 40 includes an optical coupler U2, a third electronic switch T3, a fourth electronic switch T4, a sixth resistor R6, and a seventh resistor R7. The first input terminal I1 of the optical coupler U2 is connected to the control unit 50 via the sixth resistor R6. The second input terminal I2 of the optical coupler U2 is connected to the negative electrode of the power supply unit 10. The first output terminal O1 of the coupler U2 is connected to the control terminal of the third electronic switch T3. The second output terminal O2 of the optical coupler U2 is connected to the reference zero point DR-GND. The first connection terminal of the third electronic switch T3 is connected to the reference zero point DR?GND. The second connection terminal of the third electronic switch T3 is connected to the first connection terminal of the fourth electronic switch T4. The control terminal of the fourth electronic switch T4 is connected to the power conversion unit 30 via the seventh resistor R7. The second connection terminal of the fourth electronic switch T4 is connected to the power conversion unit 30.

[0032] In one embodiment, the optical coupler U2 includes a light-emitting element D1 and a light-receiving element Q3. The first end of the light-emitting element D1 functions as the first input terminal I1 of the optical coupler U2. The second end of the light-emitting element D1 functions as the second input terminal I2 of the optical coupler U2. The first end of the light-receiving element Q3 functions as the first output terminal O1 of the optical coupler U2. The second end of the light-receiving element Q3 functions as the second output terminal of the optical coupler U2.

[0033] In this embodiment, the light-emitting element D1 is a light-emitting diode, and the first end and the second end of the light-emitting element D1 correspond to the anode and the cathode of the light-emitting diode, respectively. The light-receiving element Q3 is a photosensitive transistor, and the first end and the second end of the light-receiving element Q3 correspond to the collector and the emitter of the photosensitive transistor, respectively.

[0034] In this embodiment, the third electronic switch T3 is a PNP transistor. The control terminal, the first connection terminal, and the second connection terminal of the third electronic switch T3 correspond to the base, the collector, and the emitter of the PNP transistor, respectively. The fourth electronic switch T4 is an NPN transistor. The control terminal, the first connection terminal, and the second connection terminal of the fourth electronic switch T4 correspond to the base, the emitter, and the collector of the NPN transistor, respectively. In other embodiments, the third electronic switch T3 can be other switches having similar functions, such as a PMOS field-effect transistor and an insulated gate bipolar transistor (IGBT). The fourth electronic switch T4 can be other switches having similar functions, such as an NMOS field-effect transistor and an IGBT.

[0035] The current detection unit 60 includes a current sampling resistor R1. For example, in one embodiment, both ends of the current sampling resistor R1 can be connected to two input terminals of an operational amplifier, and according to the voltage amplified by the operational amplifier and then output, it is determined whether the current in the circuit exceeds a preset threshold value. Since this is a prior art, it will not be described in detail here. In other embodiments, the current detection unit 60 can further include a current sensor (such as a Hall sensor), and the current in the circuit is collected by the current sensor.

[0036] Hereinafter, the operating principle of the NMOS switch driving circuit 100 in FIG. 4 will be introduced.

[0037] When it is detected by the control unit 50 that the load 200 needs to be started with the load 200 connected to the first interface N1 and the second interface N2, the control unit 50 outputs a high-level signal and a low-level signal to the first electronic switch T1 and the optocoupler U2 separately. Among them, the high-level signal output to the first electronic switch T1 is a conversion signal, and the low-level signal output to the optocoupler U2 is a drive signal. Since the first electronic switch T1 receives the high-level signal and turns on, the gate of the second electronic switch T2 is at a low level and thus turns on. At this time, the first voltage output from the power supply unit 10 can be output to the conversion power supply U1 via the second electronic switch T2, and the conversion power supply U1 converts the first voltage into a certain drive voltage and then outputs it.

[0038] When the optocoupler U2 receives the low-level signal, the light-emitting element D1 turns off and does not emit light. Since the light-receiving element Q3 does not receive light, it turns off. The base of the third electronic switch T3 is at a high level and thus turns off, and the fourth electronic switch T4 turns on. In this way, the drive voltage output from the conversion power supply U1 can be output to the first NMOS field-effect transistor Q1 and the second NMOS field-effect transistor Q2, driving the first NMOS field-effect transistor Q1 and the second NMOS field-effect transistor Q2 to turn on. The power supply unit 10 can output the first voltage to the load 200 to supply power to the load 200.

[0039] Referring to FIG. 5, in some embodiments, the power conversion unit 30 further includes a first diode D2 and at least one capacitor. In the embodiments of the present application, the power conversion unit 30 includes a first capacitor C1 and a second capacitor C2. The anode of the first diode D2 is connected to the second connection end of the second electronic switch T2, and the cathode of the first diode D2 is connected to the first input end of the converted power supply U1. The first capacitor C1 and the second capacitor C2 are connected in parallel between the first input end of the converted power supply U1 and the negative electrode of the power supply unit 10. In this way, even if the power supply unit 10 instantaneously loses power, the first capacitor C1 and the second capacitor C2 can continue to supply power to the load 200, further improving the operating stability of the load 200.

[0040] The drive unit 40 further includes a second diode D3 and a third capacitor C3. The anode of the second diode D3 is electrically connected to the first output end of the converted power supply U1, and the cathode of the second diode D3 is electrically connected to the second connection end of the fourth electronic switch T4. One end of the third capacitor C3 is connected to the cathode of the second diode D3, and the other end of the third capacitor C3 is connected to the reference zero point DR-GND. In this way, when the converted power supply U1 instantaneously fails, the third capacitor C3 can continue to supply power to the load 200, further improving the operating stability and reliability of the system.

[0041] Furthermore, in order to extend the service life of the optical coupler U2, the drive unit 40 further includes a fifth electronic switch T5, a sixth electronic switch T6, and eighth to tenth resistors R8 to R10. The control terminal of the fifth electronic switch T5 is connected to the reference zero point DR-GND via the eighth resistor R8, the first connection terminal of the fifth electronic switch T5 is connected to the reference zero point DR-GND, and the second connection terminal of the fifth electronic switch T5 is connected to the control terminal of the third electronic switch T3. The control terminal of the fifth electronic switch T5 is further connected to the first connection terminal of the sixth electronic switch T6 via the ninth resistor R9. The control terminal of the sixth electronic switch T6 is connected to the first output terminal (O1) of the optical coupler U2, and the control terminal of the sixth electronic switch T6 is further connected to the cathode of the second diode D3 via the tenth resistor R10. The second connection terminal of the sixth electronic switch T6 is connected to the cathode of the second diode D3.

[0042] The operating principle of the NMOS switch drive circuit 100 in FIG. 5 will be introduced below.

[0043] When the control unit 50 detects that the load 200 needs to be started by being connected to the first interface N1 and the second interface N2, the control unit 50 outputs a high-level signal to the first electronic switch T1 and the optical coupler U2 respectively. Among them, the high-level signal output to the first electronic switch T1 is a conversion signal, and the high-level signal output to the optical coupler U2 is a drive signal. Since the first electronic switch T1 receives the high-level signal and turns on, the gate of the second electronic switch T2 is at a low level and turns on. At this time, the first voltage output from the power supply unit 10 can be output to the conversion power supply U1 via the second electronic switch T2 and the first diode D2, and the conversion power supply U1 converts the first voltage into a certain drive voltage and then outputs it. Even if the power supply unit 10 loses power instantaneously, the power stored in the first capacitor C1 and the second capacitor C2 can continue to supply power to the load 200.

[0044] When the optical coupler U2 receives a high-level signal, the light-emitting element D1 emits light. Since the light-receiving element Q3 receives the light and turns on, the sixth electronic switch T6 turns off, the fifth electronic switch T5 and the third electronic switch T3 turn off, and the fourth electronic switch T4 turns on. In this way, the driving voltage output from the conversion power supply U1 can be output to the first NMOS field-effect transistor Q1 and the second NMOS field-effect transistor Q2 through the second diode D3, driving the first NMOS field-effect transistor Q1 and the second NMOS field-effect transistor Q2, so that the first NMOS field-effect transistor Q1 and the second NMOS field-effect transistor Q2 turn on, and the power supply unit 10 can output a first voltage to the load 200 to supply power to the load 200. Even if the front end loses power instantaneously, the power stored in the third capacitor C3 can continue to supply power to the load 200.

[0045] In the embodiment of the present application, when it is not necessary to supply power to the load 200, the optical coupler U2 is in a non-operating state. The optical coupler U2 operates only when power is supplied to the load 200, so the service life of the optical coupler U2 can be extended.

[0046] The above are the preferred embodiments of the present invention. It should be noted that those skilled in the art can make some improvements and modifications without departing from the principle of the present invention, and such improvements and modifications are also within the protection scope of the present invention.

Claims

1. An NMOS switch driving circuit applied to a power supply device having a first interface, wherein the NMOS switch driving circuit includes a power supply unit, a switch unit, a power conversion unit, a driving unit, and a control unit, The power supply unit is used to output a first voltage, The switch unit is electrically connected between the power supply unit and the first interface, and is used to establish or disconnect the electrical connection between the power supply unit and the first interface, and the switch unit includes at least one NMOS switch, One end of the power conversion unit is connected to the power supply unit, and the other end of the power conversion unit is electrically connected to the switch unit through the driving unit, The power conversion unit is used to convert the first voltage into a certain driving voltage and output it to the switch unit through the driving unit, and drive the switch unit to conduct, so as to establish the electrical connection between the power supply unit and the first interface, The source of the NMOS switch is connected to the reference zero point, The control unit is electrically connected to the power conversion unit and the driving unit respectively, The control unit is used to output a conversion signal to the power conversion unit and a driving signal to the driving unit, The power conversion unit converts the first voltage into the driving voltage according to the conversion signal, The driving unit outputs the driving voltage to the switch unit according to the driving signal to drive the switch unit to conduct, An NMOS switch driving circuit characterized by the above.

2. The power supply device further has a second interface, The NMOS switch driving circuit further includes a current detection unit, The current detection unit is electrically connected between the power supply unit and the second interface, and is used to detect the output current of the power supply unit, The control unit is electrically connected to the current detection unit and collects the current signal detected by the current detection unit, When the current signal collected by the control unit is greater than a preset threshold value, the control unit stops the output of the conversion signal and / or the drive signal. The NMOS switch drive circuit according to claim 1, characterized in that.

3. The switch unit is electrically connected between the positive electrode of the power supply unit and the first interface. The NMOS switch drive circuit according to any one of claims 1 to 2, characterized in that.

4. The power conversion unit further includes a first electronic switch, a second electronic switch, and a conversion power supply. The control end of the first electronic switch is connected to the control unit, the first connection end of the first electronic switch is connected to the negative electrode of the power supply unit, and the second connection end of the first electronic switch is connected to the control end of the second electronic switch. The first connection end of the second electronic switch is connected to the positive electrode of the power supply unit, the second connection end of the second electronic switch is connected to the first input end of the conversion power supply. The second input end of the conversion power supply is connected to the negative electrode of the power supply unit, the first output end of the conversion power supply is connected to the drive unit, and the second output end of the conversion power supply is connected to the reference zero point. The NMOS switch drive circuit according to any one of claims 1 to 3, characterized in that.

5. The conversion power supply is a stabilized power supply with a wide input range. The NMOS switch drive circuit according to claim 4, characterized in that.

6. The drive unit includes an optical coupler, a third electronic switch, and a fourth electronic switch. The first input end of the optical coupler is connected to the control unit, the second input end of the optical coupler is connected to the negative electrode of the power supply unit, the first output end of the optical coupler is connected to the control end of the third electronic switch, and the second output end of the optical coupler is connected to the reference zero point. The first connection end of the third electronic switch is connected to the reference zero point, and the second connection end of the third electronic switch is connected to the first connection end of the fourth electronic switch. The control end of the fourth electronic switch is connected to the power conversion unit, and the second connection end of the fourth electronic switch is connected to the power conversion unit. The NMOS switch drive circuit according to any one of claims 1 to 5, characterized in that.

7. The optical coupler includes a light emitting element and a light receiving element. The first end of the light-emitting element functions as the first input end of the optical coupler, the second end of the light-emitting element functions as the second input end of the optical coupler, the first end of the light-receiving element functions as the first output end of the optical coupler, and the second end of the light-receiving element functions as the second output end of the optical coupler. The NMOS switch driving circuit according to claim 6, characterized in that.

8. The driving unit includes an optical coupler, a third electronic switch, a fourth electronic switch, a fifth electronic switch, and a sixth electronic switch. The optical coupler includes a light-emitting element and a light-receiving element. The first end of the light-emitting element functions as the first input end of the optical coupler, the second end of the light-emitting element functions as the second input end of the optical coupler, the first end of the light-receiving element functions as the first output end of the optical coupler, and the second end of the light-receiving element functions as the second output end of the optical coupler. The first input end of the optical coupler is connected to the control unit and is used to receive the driving signal. The second input end of the optical coupler is connected to the negative electrode of the power supply unit. The first output end of the optical coupler is connected to the control end of the sixth electronic switch. The second output end of the optical coupler is connected to the reference zero point. The first connection end of the third electronic switch is connected to the reference zero point, and the second connection end of the third electronic switch is connected to the first connection end of the fourth electronic switch. The control end of the fourth electronic switch is connected to the power conversion unit. The second connection end of the fourth electronic switch is connected to the power conversion unit. The first connection end of the fourth electronic switch is used to output the driving voltage when the fourth electronic switch is turned on. The control end of the fifth electronic switch is connected to the reference zero point. The first connection end of the fifth electronic switch is connected to the reference zero point. The second connection end of the fifth electronic switch is connected to the control end of the third electronic switch. The control end of the fifth electronic switch is further connected to the first connection end of the sixth electronic switch. The control end of the sixth electronic switch is connected to the first output end of the optical coupler. The control end of the sixth electronic switch is further connected to the power conversion unit. The second connection end of the sixth electronic switch is connected to the power conversion unit. The NMOS switch driving circuit according to claim 1, characterized in that.

9. A power supply device including a first interface and a second interface. The power supply device further includes the NMOS switch driving circuit according to any one of claims 1 to 8, and the NMOS switch driving circuit is connected to a load via the first interface and the second interface. A power supply device characterized by the above.

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