High-voltage starting circuit, motor controller and vehicle controller

Abstract

The invention discloses a high-voltage starting circuit, a motor controller and a vehicle controller, the high-voltage starting circuit comprises a grid voltage switching module, a grid voltage stabilizing module, an NMOS tube and an output voltage switching module, the input end of the grid voltage switching module is connected with the voltage output end of a switching power supply circuit; the output end of the output voltage switching module is connected with the input end of the grid voltage stabilizing module, the output end of the grid voltage stabilizing module is connected with the grid end of the NMOS tube, the drain end of the NMOS tube is connected with the drain end of a main switching tube in the switching power supply circuit, and the source end of the NMOS tube is connected with the first input end of the output voltage switching module. The second input end of the output voltage switching module is connected with the voltage output end of the switching power supply circuit, and the output end is connected with the power supply end of the switching power supply control chip. According to the high-voltage starting circuit, the high-voltage MOS tube is used for replacing the function of a high-voltage LDO, and the high-voltage MOS tube is accurately controlled to work in a constant-current area, so that stable power supply voltage is provided for a switching power supply control chip.

Description

Technical Field

[0001] The invention belongs to the field of power electronics, and in particular relates to a high-voltage starting circuit, a motor controller and a vehicle controller. Background Art

[0002] In high voltage applications involving switching power supplies, see the attached Figure 1 As shown, when the bus voltage Vin is much higher than the operating voltage requirement of the switching power supply control chip, ensuring the stable operation of the switching power supply is closely linked to the stable operation of its control chip, and the normal operation of the control chip depends on a stable and reliable low-voltage power supply Vcc.

[0003] For traditional high voltage power supply methods, please refer to the attached Figure 2 As shown, a high-voltage low-dropout linear regulator (LowDropout Regulator, LDO) is usually relied on to convert high voltage into low voltage electricity suitable for chip use. First, since the high-voltage LDO is always connected to the high-voltage bus, its power consumption is relatively large, especially in the case of a high step-down ratio. Secondly, the input voltage range of the high-voltage LDO is limited, usually narrow, which limits its application under a wide range of input voltage conditions. At the same time, due to the switching action of the power switching device on the high-voltage bus, voltage pulse spikes will be generated. These spikes may exceed the rated input voltage range of the high-voltage LDO, causing the high-voltage LDO to fail, thereby affecting the stability and reliability of the entire power supply system. Therefore, how to safely and effectively extract stable and reliable low-voltage electricity from the high-voltage side to power the control chip has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a high-voltage starting circuit, a motor controller and a vehicle controller, which use a high-voltage MOS tube to replace the function of a high-voltage LDO, and accurately control the high-voltage MOS tube to work in a constant current region to provide a stable power supply voltage for a switching power supply control chip, thereby solving the technical problems of high power consumption and limited input voltage range when using a high-voltage LDO for voltage reduction in the prior art.

[0005] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0006] The present invention provides a high-voltage startup circuit, which includes: a gate voltage switching module, a gate voltage stabilizing module, an NMOS tube and an output voltage switching module;

[0007] The input end of the gate voltage switching module is connected to the voltage output end of the switching power supply circuit, and the output end is connected to the input end of the gate voltage stabilizing module;

[0008] The output end of the gate voltage stabilization module is connected to the gate end of the NMOS tube;

[0009] The drain end of the NMOS tube is connected to the drain end of the main switch tube in the switching power supply circuit for receiving high voltage input, and the source end of the NMOS tube is connected to the first input end of the output voltage switching module;

[0010] The second input terminal of the output voltage switching module is connected to the voltage output terminal of the switching power supply circuit, and the output terminal is connected to the power supply terminal of the switching power supply control chip.

[0011] In one embodiment of the present invention, the gate voltage switching module includes a first voltage stabilizing diode, a first resistor, a second resistor and an NPN transistor;

[0012] The cathode of the first voltage stabilizing diode is connected to the voltage output terminal of the switching power supply circuit, and the anode is connected to the first end of the first resistor;

[0013] The second end of the first resistor is connected in series with the second resistor and then grounded;

[0014] A midpoint between the first resistor and the second resistor is connected to the base of the NPN transistor;

[0015] The collector of the NPN transistor is connected to the input end of the gate voltage stabilizing module, and the emitter is connected to the ground end.

[0016] In one embodiment of the present invention, the gate voltage stabilizing module includes a third resistor, a second voltage stabilizing diode and a third voltage stabilizing diode;

[0017] The first end of the third resistor is connected to the drain of the main switch tube in the switching power supply circuit;

[0018] The second end of the third resistor is connected to the cathode of the second voltage stabilizing diode and is connected to the gate end of the NMOS tube as the output end of the gate voltage stabilizing module;

[0019] The anode of the second voltage stabilizing diode is connected to the cathode of the third voltage stabilizing diode and serves as the input end of the gate voltage stabilizing module and is connected to the output end of the gate voltage switching module;

[0020] The anode of the third voltage stabilizing diode is connected to the ground.

[0021] In one embodiment of the present invention, the gate voltage stabilizing module further includes a first capacitor, a first end of the first capacitor is connected to the cathode of the second voltage stabilizing diode, and a second end of the first capacitor is connected to the ground.

[0022] In one embodiment of the present invention, the output voltage switching module includes a first diode, a second diode and a fourth resistor;

[0023] The anode of the first diode is connected to the source end of the NMOS tube;

[0024] The cathode of the first diode is connected to the first end of the fourth resistor and is connected to the power supply end of the switching power supply control chip as the output end of the output voltage switching module;

[0025] The anode of the second diode is connected to the voltage output terminal of the switching power supply circuit, and the output terminal is connected to the cathode of the first diode;

[0026] The second end of the fourth resistor is connected to the ground.

[0027] In one embodiment of the present invention, the output voltage switching module further includes a second capacitor, a first end of the second capacitor is connected to the first end of the fourth resistor, and a second end of the second capacitor is connected to the ground.

[0028] In one embodiment of the present invention, the forward conduction voltage of the first diode is the same as that of the second diode.

[0029] In one embodiment of the present invention, when the output terminal voltage of the switching power supply circuit is greater than the source terminal voltage of the NMOS tube, the power supply terminal voltage of the switching power supply control chip is provided by the output terminal voltage of the switching power supply circuit.

[0030] Based on the same inventive concept, another embodiment of the present invention further provides a motor controller, which includes the high-voltage starting circuit as described in any of the above embodiments.

[0031] Based on the same inventive concept, another embodiment of the present invention further provides a vehicle controller, which includes the high-voltage starting circuit as described in any of the above embodiments.

[0032] As described above, the present invention provides a high-voltage startup circuit, including a gate voltage switching module, a gate voltage stabilizing module, an NMOS tube and an output voltage switching module, wherein the input end of the gate voltage switching module is connected to the voltage output end of the switching power supply circuit, the output end is connected to the input end of the gate voltage stabilizing module, the output end of the gate voltage stabilizing module is connected to the gate end of the NMOS tube, the drain end of the NMOS tube is connected to the drain end of the main switch tube in the switching power supply circuit, and is used to receive high-voltage input, the source end of the NMOS tube is connected to the first input end of the output voltage switching module, the second input end of the output voltage switching module is connected to the voltage output end of the switching power supply circuit, and the output end is connected to the power supply end of the switching power supply control chip. The high-voltage startup circuit uses a high-voltage MOS tube to replace the function of the high-voltage LDO, and can stably provide a working voltage for the switching power supply control chip under a high-voltage environment. Compared with the high-voltage LDO, this method has stronger adaptability to the input voltage and a wider input voltage range. In addition, the power supply position of the high-voltage startup circuit is set to the drain of the main switch tube in the switching power supply circuit. The absorption circuit of the main switch tube can absorb the sudden voltage energy at both ends of the switch tube to prevent the voltage spike from breaking through the high-voltage MOS tube. In addition, the high-voltage startup circuit can control the amplitude of the power supply voltage of the switching power supply control chip by adjusting the circuit parameters, so that the application range of the switching power supply control chip in a high-voltage environment is more extensive. Of course, any product implementing the present invention does not necessarily need to achieve all the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 It is a circuit diagram of a switching power supply circuit in the prior art.

[0035] Figure 2 It is a circuit diagram of a high voltage power supply method in the prior art.

[0036] Figure 3 A structural block diagram of a high-voltage startup circuit provided by an exemplary embodiment of the present application.

[0037] Figure 4 A circuit diagram of a high-voltage startup circuit provided by an exemplary embodiment of the present application.

[0038] Figure 5A schematic diagram of a charging and discharging current path generated by a high-frequency jump voltage provided by an exemplary embodiment of the present application.

[0039] Figure 6 A circuit diagram of an exemplary embodiment of the present application showing that the power supply location of a high-voltage starting circuit is set on a DC bus of a switching power supply circuit.

[0040] Figure 7 A circuit diagram of an exemplary embodiment of the present application provides a high-voltage startup circuit in which the power supply position is set at the drain of the main switch tube in the switching power supply circuit.

[0041] Figure 8 A schematic diagram of key waveforms of a high-voltage startup circuit provided by an exemplary embodiment of the present application.

[0042] The reference numerals are as follows:

[0043] 100 Switching Power Supply Circuit

[0044] 200 High voltage starting circuit

[0045] 210 Gate voltage switching module

[0046] 220 Gate voltage regulator module

[0047] 230 Output voltage switching module

[0048] 300 Switching power supply control chip DETAILED DESCRIPTION

[0049] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0050] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0051] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0052] In order to solve the technical problems of high power consumption and limited input voltage range when using high-voltage LDO for voltage reduction in the prior art, the present invention provides a high-voltage starting circuit, which uses a high-voltage MOS tube to replace the function of the high-voltage LDO, and accurately controls the high-voltage MOS tube to work in the constant current region, so as to provide a stable power supply voltage for the switching power supply control chip.

[0053] See also Figure 3 As shown, in an exemplary embodiment of the present application, the high-voltage startup circuit 200 includes a gate voltage switching module 210, a gate voltage stabilizing module 220, an NMOS tube M1 and an output voltage switching module 230. The input end of the gate voltage switching module 210 is connected to the voltage output end Vo of the switching power supply circuit 100, and the output end is connected to the input end of the gate voltage stabilizing module 220. The output end of the gate voltage stabilizing module 220 is connected to the gate end of the NMOS tube M1, and the drain end of the NMOS tube M1 is connected to the drain end SW_D of the main switch tube SW in the switching power supply circuit 100 for receiving high-voltage input. The source end of the NMOS tube M1 is connected to the first input end of the output voltage switching module 230, the second input end of the output voltage switching module 230 is connected to the voltage output end Vo of the switching power supply circuit 100, and the output end is connected to the power supply end Vcc of the switching power supply control chip 300. It should be noted that in this embodiment, please refer to Figure 1 As shown, the switching power supply circuit is a flyback switching power supply circuit.

[0054] See also Figure 4 As shown, in an exemplary embodiment of the present application, the gate voltage switching module 210 includes a first voltage stabilizing diode Z1, a first resistor R1, a second resistor R2 and an NPN transistor Q1, the cathode of the first voltage stabilizing diode Z1 is connected to the voltage output terminal Vo of the switching power supply circuit 100, the anode is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected in series with the second resistor R2 and then grounded, the midpoint of the first resistor R1 and the second resistor R2 is connected to the base of the NPN transistor Q1, the collector of the NPN transistor Q1 is connected to the input end of the gate voltage stabilizing module 220, and the emitter is connected to the ground.

[0055] It should be noted that the gate voltage switching module 210 is used to receive the voltage at the voltage output terminal Vo of the switching power supply circuit 100 and control the on and off of the NPN transistor Q1, thereby controlling the magnitude of the gate bias voltage of the NMOS transistor M1.

[0056] See also Figure 4 As shown, in an exemplary embodiment of the present application, the gate voltage stabilizing module 220 includes a third resistor R3, a second voltage stabilizing diode Z2 and a third voltage stabilizing diode Z3, the first end of the third resistor R3 is connected to the drain SW_D of the main switch tube SW in the switching power supply circuit 100, the second end of the third resistor R3 is connected to the cathode of the second voltage stabilizing diode Z2 and is connected to the gate end of the NMOS tube M1 as the output end of the gate voltage stabilizing module 220, the anode of the second voltage stabilizing diode Z2 is connected to the cathode of the third voltage stabilizing diode Z3 and is connected to the output end of the gate voltage switching module 210 as the input end of the gate voltage stabilizing module 220, and the anode of the third voltage stabilizing diode Z3 is connected to the ground end.

[0057] It should be noted that the gate voltage stabilizing module 220 is used to provide a stable gate bias voltage for the NMOS transistor Q1 to ensure that the NMOS transistor operates in a constant current region. In addition, the third resistor R3 is a current limiting resistor, which is used to prevent the current passing through the second voltage stabilizing diode Z2 and the third voltage stabilizing diode Z3 from being too large and causing device damage, thereby affecting the normal operation of the high-voltage startup circuit 200.

[0058] See also Figure 4 As shown, in an exemplary embodiment of the present application, the gate voltage stabilization module 220 further includes a first capacitor C1, a first end of the first capacitor C1 is connected to the cathode of the second voltage stabilizing diode Z2, and a second end of the first capacitor C1 is connected to the ground. The first capacitor C1 is a filter capacitor, which is used to filter the gate control voltage of the NMOS tube to prevent the voltage spike from causing the gate of the NMOS tube to break down.

[0059] See also Figure 4 As shown, in an exemplary embodiment of the present application, the output voltage switching module 230 includes a first diode D1, a second diode D2 and a fourth resistor R4, the anode of the first diode D1 is connected to the source end of the NMOS tube M1, the cathode of the first diode D1 is connected to the first end of the fourth resistor R4 and is connected to the power supply end Vcc of the switching power supply control chip 300 as the output end of the output voltage switching module 230, the anode of the second diode D2 is connected to the voltage output end Vo of the switching power supply circuit 100, and the output end is connected to the cathode of the first diode D1, and the second end of the fourth resistor R4 is connected to the ground.

[0060] See also Figure 4 As shown, in an exemplary embodiment of the present application, the output voltage switching module 230 further includes a second capacitor C2, a first end of the second capacitor C2 is connected to the first end of the fourth resistor R4, and a second end of the second capacitor C2 is connected to the ground. The second capacitor C2 is a filter capacitor, which is used to filter the output voltage Vcc of the high-voltage startup circuit 200 to provide a stable rated operating voltage for the switching power supply control chip 300.

[0061] It should be noted that the forward conduction voltage of the first diode D1 and the second diode D2 is the same, and the first diode D1 and the second diode D2 include but are not limited to a silicon diode and a germanium diode.

[0062] In an exemplary embodiment of the present application, when the output voltage Vo of the switching power supply circuit 100 is greater than the source voltage of the NMOS tube M1, the power supply voltage Vcc of the switching power supply control chip 300 is provided by the output voltage Vo of the switching power supply circuit 100.

[0063] The working principle of the high voltage starting circuit 200 will be described in detail below:

[0064] When using a flyback switching power supply for high voltage applications, the voltage on the bus T+ will have some high-frequency voltage spikes in addition to the high-voltage DC voltage. In order to widen the power supply voltage range, a high-voltage MOS tube is used to replace the function of the high-voltage LDO, and the MOS tube is controlled to work in the constant current region to obtain the power supply voltage of the switching power supply control chip. Compared with the high-voltage LDO, this method has lower requirements on the input voltage range. Please refer to the attached Figure 6 As shown in FIG. 1 , if the power supply position of the high-voltage startup circuit 200 is set on the bus T+, the voltage spike on the bus T+ may break down the NMOS tube M1 in the high-voltage startup circuit 200. Therefore, in this embodiment, the power supply position of the high-voltage startup circuit 200 is set at the drain SW_D of the main switch tube SW in the switching power supply circuit 100. Please refer to the attached Figure 7 As shown in FIG. 1 , when there is a high voltage spike interference on the voltage of the bus T+, the RCD absorption circuit (i.e., the attached Figure 7 The circuit in the red box in the middle can absorb the sudden voltage energy at both ends of the main switch tube SW, thereby preventing excessively high voltage spikes from appearing at both ends of the main switch tube SW.

[0065] However, if the power supply position of the high-voltage startup circuit 200 is transferred from the bus T+ to the drain SW of the main switch tube SW, the high dv / dt generated by the main switch tube SW when it is turned on and off may affect the normal operation of the high-voltage startup circuit 200. Specifically, the high dv / dt jump voltage will cause the high-frequency current to flow to the second voltage zener diode Z2 and the third voltage zener diode Z3 through the parasitic capacitor Cgd of the NMOS tube M1. The peak value of the high-frequency jump current may exceed the maximum allowable current of the NPN transistor Q1, thereby causing the NPN transistor Q1 to have a risk of failure. Please refer to the attached figure for the charging and discharging current path generated by the high-frequency jump voltage. Figure 5 Therefore, please continue to refer to the attached Figure 7 As shown, by adding the second voltage zener diode Z2 to increase the impedance when the NPN transistor Q1 is turned on, when the output of the switching power supply circuit 100 is established, the output voltage Vo of the switching power supply circuit 100 breaks down the first voltage zener diode Z1, the NPN transistor Q1 is turned on, and the gate voltage of the NMOS tube M1 is clamped to the voltage of the second voltage zener diode Z2.

[0066] For details, please refer to the attached Figure 7 and attached Figure 8As shown, when the bus voltage T+ rises from zero voltage, the switching power supply circuit 100 is not working at this time, and the output voltage flows to the SW_D node through the primary winding Lp of the transformer, and the voltage at this node also rises as the bus voltage T+ rises. During the voltage rise of the SW_D node, the gate voltage of the NMOS tube M1 also gradually rises, and its source voltage rises along with the gate voltage of the NMOS tube M1. During this time, the first diode D1 is turned on, and the voltage of the output terminal Vcc of the high-voltage startup circuit 200 rises along with the source voltage of the NMOS tube M1. At time t0, when the voltage of Vcc meets the working voltage of the switching power supply control chip 300, the switching power supply control chip 300 can start to work normally, and then the output terminal voltage Vo of the switching power supply circuit 100 rises linearly. At time t1, the voltage of the SW_D node rises to a level that can break down the second voltage zener diode Z2 and the third voltage zener diode Z3, and the source voltage of the NMOS tube M1 is stabilized at a voltage of VZ2+VZ3-Vth, wherein VZ2 and VZ3 are the breakdown voltages of the second voltage zener diode Z2 and the third voltage zener diode Z3, respectively, and Vth is the critical conduction voltage of the NMOS tube M1. At time t3, when the voltage value of the output terminal voltage Vo of the switching power supply circuit 100 is greater than the source voltage of the NMOS tube M1, at this time, the first diode D1 is reversely cut off, and the second diode D2 is forwardly turned on, and thereafter the power supply voltage of the switching power supply control chip 300 is provided by the output terminal voltage Vo of the switching power supply circuit 100. At time t4, when the voltage value of the output voltage Vo of the switching power supply circuit 100 reaches VZ1+2*VBE, the first voltage-stabilizing diode Z1 will be broken down, and the NPN transistor Q1 will be turned on. At this time, the gate voltage of the NMOS tube M1 will be clamped to the VZ2 voltage, where VBE is the emitter junction conduction voltage of the NPN transistor Q1. At this moment, the source voltage of the NMOS tube M1 will drop to VZ2-Vth, and when VZ2-Vth is less than the preset voltage threshold Vo1, the first diode D1 is reversely cut off. The high-voltage startup circuit 200 can provide reliable and stable power supply for the switching power supply control chip 300 during the bus T+ voltage startup process, and can reliably switch the power supply after the output voltage of the switching power supply circuit 100 is established.

[0067] In summary, a high-voltage startup circuit 200 provided by the present invention includes a gate voltage switching module 210, a gate voltage stabilizing module 220, an NMOS tube M1 and an output voltage switching module 230. The input end of the gate voltage switching module 210 is connected to the voltage output end Vo of the switching power supply circuit 100, and the output end is connected to the input end of the gate voltage stabilizing module 220. The output end of the gate voltage stabilizing module 220 is connected to the gate end of the NMOS tube M1, and the drain end of the NMOS tube M1 is connected to the drain end SW_D of the main switch tube SW in the switching power supply circuit 100 for receiving high-voltage input. The source end of the NMOS tube M1 is connected to the first input end of the output voltage switching module 230, the second input end of the output voltage switching module 230 is connected to the voltage output end Vo of the switching power supply circuit 100, and the output end is connected to the power supply end Vcc of the switching power supply control chip 300. The high-voltage startup circuit 200 uses a high-voltage MOS tube to replace the function of the high-voltage LDO, and can stably provide the working voltage for the switching power supply control chip 300 under a high-voltage environment. Compared with the high-voltage LDO, this method has stronger adaptability to the input voltage and a wider input voltage range. In addition, the power supply position of the high-voltage startup circuit 200 is set to the drain SW_D of the main switch tube SW in the switching power supply circuit 100. The RCD absorption circuit of the main switch tube SW can absorb the sudden voltage energy at both ends of the main switch tube SW to prevent the voltage spike from breaking through the high-voltage MOS tube. In addition, the high-voltage startup circuit 200 can control the amplitude of the power supply voltage of the switching power supply control chip 300 by adjusting the circuit parameters, so that the application range of the switching power supply control chip 300 under a high-voltage environment is wider.

[0068] Based on the same inventive concept, another embodiment of the present invention further provides a motor controller, the motor controller comprising the high-voltage starting circuit described in any of the above embodiments. Since the motor controller provided in this embodiment belongs to the same inventive concept as the high-voltage starting circuit provided in any of the above embodiments, it has at least the same beneficial effects as the high-voltage starting circuit, and will not be described one by one here.

[0069] Based on the same inventive concept, another embodiment of the present invention further provides a vehicle controller, the vehicle controller comprising the high-voltage starting circuit described in any of the above embodiments. Since the vehicle controller provided in this embodiment belongs to the same inventive concept as the high-voltage starting circuit provided in any of the above embodiments, it has at least the same beneficial effects as the high-voltage starting circuit, and will not be described one by one here.

[0070] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A high voltage starting circuit, characterized in that: include: Gate voltage switching module, gate voltage stabilization module, NMOS tube and output voltage switching module; The input end of the gate voltage switching module is connected to the voltage output end of the switching power supply circuit, and the output end is connected to the input end of the gate voltage stabilizing module; The output end of the gate voltage stabilization module is connected to the gate end of the NMOS tube; The drain end of the NMOS tube is connected to the drain end of the main switch tube in the switching power supply circuit for receiving high voltage input, and the source end of the NMOS tube is connected to the first input end of the output voltage switching module; The second input terminal of the output voltage switching module is connected to the voltage output terminal of the switching power supply circuit, and the output terminal is connected to the power supply terminal of the switching power supply control chip.

2. The high voltage starting circuit according to claim 1, characterized in that: The gate voltage switching module includes a first voltage stabilizing diode, a first resistor, a second resistor and an NPN transistor; The cathode of the first voltage stabilizing diode is connected to the voltage output terminal of the switching power supply circuit, and the anode is connected to the first end of the first resistor; The second end of the first resistor is connected in series with the second resistor and then grounded; A midpoint between the first resistor and the second resistor is connected to the base of the NPN transistor; The collector of the NPN transistor is connected to the input end of the gate voltage stabilizing module, and the emitter is connected to the ground end.

3. The high voltage starting circuit according to claim 1, characterized in that: The gate voltage stabilizing module includes a third resistor, a second voltage stabilizing diode and a third voltage stabilizing diode; The first end of the third resistor is connected to the drain of the main switch tube in the switching power supply circuit; The second end of the third resistor is connected to the cathode of the second voltage stabilizing diode and is connected to the gate end of the NMOS tube as the output end of the gate voltage stabilizing module; The anode of the second voltage stabilizing diode is connected to the cathode of the third voltage stabilizing diode and serves as the input end of the gate voltage stabilizing module and is connected to the output end of the gate voltage switching module; The anode of the third voltage stabilizing diode is connected to the ground.

4. The high voltage starting circuit according to claim 3, characterized in that: The gate voltage stabilizing module further includes a first capacitor, a first end of the first capacitor is connected to the cathode of the second voltage stabilizing diode, and a second end of the first capacitor is connected to the ground.

5. The high voltage starting circuit according to claim 1, characterized in that: The output voltage switching module includes a first diode, a second diode and a fourth resistor; The anode of the first diode is connected to the source end of the NMOS tube; The cathode of the first diode is connected to the first end of the fourth resistor and is connected to the power supply end of the switching power supply control chip as the output end of the output voltage switching module; The anode of the second diode is connected to the voltage output terminal of the switching power supply circuit, and the output terminal is connected to the cathode of the first diode; The second end of the fourth resistor is connected to the ground.

6. The high voltage starting circuit according to claim 5, characterized in that: The output voltage switching module further includes a second capacitor, a first end of the second capacitor is connected to the first end of the fourth resistor, and a second end of the second capacitor is connected to the ground.

7. The high voltage starting circuit according to claim 5, characterized in that: The first diode and the second diode have the same forward conduction voltage.

8. The high voltage starting circuit according to claim 1, characterized in that: When the output terminal voltage of the switching power supply circuit is greater than the source terminal voltage of the NMOS tube, the power supply terminal voltage of the switching power supply control chip is provided by the output terminal voltage of the switching power supply circuit.

9. A motor controller, characterized in that: The motor controller comprises a high voltage starting circuit as claimed in any one of claims 1 to 8.

10. A vehicle controller, characterized in that: The vehicle controller comprises a high voltage starting circuit as described in any one of claims 1-8.

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