A DCDC enabling circuit with multiple protections

Abstract

The present invention discloses a DCDC enabling circuit with multiple protections, including an undervoltage shutdown circuit, an overvoltage clamping circuit, a DCDC opening circuit, a short-circuit protection triggering circuit, a DCDC module, a charging switch circuit, a single-chip microcomputer MCU, an input Vin, and a 3.3V power supply. The present invention has deep undervoltage shutdown and short-circuit protection functions, and deep undervoltage has the advantage of low power consumption; the present invention has an overvoltage clamping function; the present invention has an input short-circuit protection function and an MCU alarm function. The present invention uses high-end MOS tubes Q5 and Q6 for switching and fast charging and discharging, with small internal resistance and large overcurrent capacity, so the stress is large and it is not easy to be damaged. When the MOS tube Q5 is damaged, the MOS tube Q6 can also maintain its function. The driver adopts optical coupling isolation enabling, which greatly improves safety.

Description

Technical Field

[0001] The invention relates to a DCDC enabling circuit with multiple protections. Background Art

[0002] Existing general DCDCs all use P tubes as high-end switches. High-voltage signal tubes have little signal and are expensive. Generally, a current-limiting resistor is added to the input end to limit the impact of the input capacitor, which affects the rapid charging and discharging of the capacitor. In addition, the DCDCs do not have a deep undervoltage protection function, withstand little stress, and are easily damaged. Summary of the invention

[0003] The object of the present invention is to overcome the deficiencies in the prior art and provide a DCDC enabling circuit with multiple protections.

[0004] In order to achieve the above object, the present invention is achieved through the following technical solutions:

[0005] A DCDC enabling circuit with multiple protections comprises an undervoltage shutdown circuit, an overvoltage clamping circuit, a DCDC opening circuit, a short-circuit protection triggering circuit, a DCDC module, a charging switch circuit, a single-chip microcomputer MCU, an input Vin, and a 3.3V power supply. The undervoltage shutdown circuit, the overvoltage clamping circuit, the DCDC opening circuit, the short-circuit protection triggering circuit, and the DCDC module are all connected to the charging switch circuit, the undervoltage shutdown circuit, the short-circuit protection triggering circuit, and the overvoltage clamping circuit are all connected to the DCDC opening circuit, the short-circuit protection triggering circuit is connected to the DCDC module, the DCDC opening circuit and the DCDC module are all connected to the single-chip microcomputer MCU, the charging switch circuit is connected to the input Vin, and the undervoltage shutdown circuit and the DCDC opening circuit are all connected to the 3.3V power supply.

[0006] Preferably, the undervoltage shutdown circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a transistor Q1, and a MOS tube Q2, one end of the resistor R1 is connected to the charging switch circuit, the other end of the resistor R1 is connected to one end of the resistor R3 through the resistor R2, the other end of the resistor R3 is connected to the ground signal GND, one end of the resistor R3 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is connected to the ground signal GND, the collector of the transistor Q1 is connected to a 3.3V power supply through a resistor R4, the G pole of the MOS tube Q2 is connected to the collector of the transistor Q1, the S pole of the MOS tube Q2 is connected to the ground signal GND, and the G pole of the MOS tube Q2 is connected to the DCDC opening circuit.

[0007] Preferably, the MOS transistor Q2 is an N-channel MOS transistor, and the transistor Q1 is an NPN transistor.

[0008] Preferably, the overvoltage clamping circuit includes a resistor R8, a Zener diode ZD1, and a Zener diode ZD2, one end of the resistor R8 is connected to the charging switch circuit, the other end of the resistor R8 is connected to the DCDC opening circuit, the other end of the resistor R8 is connected to the cathode of the Zener diode ZD2 through the Zener diode ZD1, and the anode of the Zener diode ZD2 is connected to the ground signal GND.

[0009] Preferably, the DCDC opening circuit includes an optocoupler G1, a resistor R5, a resistor R6, a resistor R7, and a transistor Q3, pin 2 of the optocoupler G1 is connected to the ground signal GND, pin 1 of the optocoupler G1 is connected to the undervoltage shutdown circuit, pin 4 of the optocoupler G1 is connected to the overvoltage clamping circuit, pin 3 of the optocoupler G1 is connected to the charging switch circuit, pin 1 of the optocoupler G1 is connected to one end of the resistor R7 through the resistor R6, one end of the resistor R7 is connected to the short-circuit protection trigger circuit, the other end of the resistor R7 is connected to the collector of the transistor Q3, the emitter of the transistor Q3 is connected to a 3.3V power supply, the base of the transistor Q3 is connected to the microcontroller MCU through the resistor R5, and one end of the resistor R7 is connected to the microcontroller MCU.

[0010] Preferably, the transistor Q3 is a PNP transistor.

[0011] Preferably, the short-circuit protection trigger circuit includes a transistor Q4, a diode D2, and a resistor R12, the collector of the transistor Q4 is connected to the DCDC module and the charging switch circuit, the emitter of the transistor Q4 is connected to the DCDC opening circuit, the base of the transistor Q4 is connected to one end of the resistor R12 through the diode D2, and the other end of the resistor R12 is connected to the collector of the transistor Q4.

[0012] Preferably, the transistor Q4 is a PNP transistor.

[0013] Preferably, the DCDC module includes a DCDC chip U1, a capacitor C2, a capacitor C3, a diode D4, and an inductor L1. The input end IN of the DCDC chip U1 is connected to one end of the capacitor C3 through the capacitor C2, and the other end of the capacitor C3 is connected to the ground signal GND. The output end OUT of the DCDC chip U1 is connected to the ground signal GND through the diode D4, and the output end OUT of the DCDC chip U1 is connected to the microcontroller MCU through the inductor L1.

[0014] Preferably, the charging switch circuit includes a diode D1, a diode D3, a diode D5, a resistor R9, a resistor R10, a resistor R11, a resistor R14, a voltage stabilizing diode ZD3, a transistor Q7, a MOS transistor Q5, a MOS transistor Q6, a large capacitor C1, and a large capacitor C4. The positive electrode of the diode D1 is connected to the input Vin, the negative electrode of the diode D1 is connected to the undervoltage shutdown circuit, the negative electrode of the diode D1 is connected to the collector of the transistor Q7 through the diode D3, the collector of the transistor Q7 is connected to the overvoltage clamping circuit, the collector of the transistor Q7 is connected to the base of the transistor Q7 through the diode D5, the emitter of the transistor Q7 is connected to one end of the large capacitor C1 through the resistor R14, and the other end of the large capacitor C1 is connected to the overvoltage clamping circuit. The large capacitor C4 is connected to the ground signal GND, the emitter of the transistor Q7 is connected to the D pole of the MOS transistor Q6, the G pole of the MOS transistor Q6 is connected to one end of the resistor R9, the other end of the resistor R9 is connected to the DCDC opening circuit, the S pole of the MOS transistor Q6 is connected to the D pole of the MOS transistor Q5, the S pole of the MOS transistor Q5 is connected to the short-circuit protection trigger circuit and the DCDC module, the G pole of the MOS transistor Q5 is connected to one end of the resistor R9 through the resistor R10, the G pole of the MOS transistor Q5 is connected to the S pole of the MOS transistor Q5 through the zener diode ZD3, the resistor R11 is connected in parallel with the zener diode ZD3, the transistor Q7 is an NPN transistor, and the MOS transistor Q5 and the MOS transistor Q6 are both N-channel MOS transistors.

[0015] The beneficial effects of the present invention are as follows: the present invention has deep undervoltage shutdown and short-circuit protection functions, and deep undervoltage has the advantage of low power consumption; the present invention has an overvoltage clamping function; the present invention has an input short-circuit protection function and an MCU alarm function. The present invention uses high-end MOS tubes Q5 and Q6 for switching and fast charging and discharging, with small internal resistance and large overcurrent capacity, so the stress is large and not easy to be damaged. When the MOS tube Q5 is damaged, the MOS tube Q6 can also maintain its function. The driver adopts optical coupling isolation to enable, which greatly improves safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a module connection diagram of the present invention;

[0017] Figure 2 It is a circuit schematic diagram of the present invention. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described below in conjunction with the accompanying drawings:

[0019] like Figure 1As shown, a DCDC enabling circuit with multiple protections includes an undervoltage shutdown circuit 1, an overvoltage clamping circuit 2, a DCDC opening circuit 3, a short-circuit protection trigger circuit 4, a DCDC module 5, a charging switch circuit 6, a single-chip microcomputer MCU8, an input Vin7, and a 3.3V power supply 9. The undervoltage shutdown circuit 1, the overvoltage clamping circuit 2, the DCDC opening circuit 3, the short-circuit protection trigger circuit 4, and the DCDC module 5 are all connected to the charging switch circuit 6, the undervoltage shutdown circuit 1, the short-circuit protection trigger circuit 4, and the overvoltage clamping circuit 2 are all connected to the DCDC opening circuit 3, the short-circuit protection trigger circuit 4 is connected to the DCDC module 5, the DCDC opening circuit 3 and the DCDC module 5 are all connected to the single-chip microcomputer MCU8, the charging switch circuit 6 is connected to the input Vin7, and the undervoltage shutdown circuit 1 and the DCDC opening circuit 3 are all connected to the 3.3V power supply 9.

[0020] Input Vin7 provides the voltage for the battery cell, which is 56-84V under normal conditions and exceeds 93V under abnormal conditions.

[0021] like Figure 2 As shown, the undervoltage shutdown circuit 1 includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a transistor Q1, and a MOS transistor Q2. One end of the resistor R1 is connected to the charging switch circuit 6, the other end of the resistor R1 is connected to one end of the resistor R3 through the resistor R2, the other end of the resistor R3 is connected to the ground signal GND, one end of the resistor R3 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is connected to the ground signal GND, the collector of the transistor Q1 is connected to the 3.3V power supply 9 through the resistor R4, the G pole of the MOS transistor Q2 is connected to the collector of the transistor Q1, the S pole of the MOS transistor Q2 is connected to the ground signal GND, and the G pole of the MOS transistor Q2 is connected to the DCDC opening circuit 3.

[0022] like Figure 2 As shown, the MOS transistor Q2 is an N-channel MOS transistor, and the transistor Q1 is an NPN transistor.

[0023] like Figure 2 As shown, the overvoltage clamping circuit 2 includes a resistor R8, a Zener diode ZD1, and a Zener diode ZD2. One end of the resistor R8 is connected to the charging switch circuit 6, and the other end of the resistor R8 is connected to the DCDC opening circuit 3. The other end of the resistor R8 is connected to the cathode of the Zener diode ZD2 through the Zener diode ZD1, and the anode of the Zener diode ZD2 is connected to the ground signal GND.

[0024] like Figure 2As shown, the DCDC opening circuit 3 includes an optocoupler G1, a resistor R5, a resistor R6, a resistor R7, and a transistor Q3. Pin 2 of the optocoupler G1 is connected to the ground signal GND, pin 1 of the optocoupler G1 is connected to the undervoltage shutdown circuit 1, pin 4 of the optocoupler G1 is connected to the overvoltage clamping circuit 2, pin 3 of the optocoupler G1 is connected to the charging switch circuit 6, pin 1 of the optocoupler G1 is connected to one end of the resistor R7 through the resistor R6, one end of the resistor R7 is connected to the short-circuit protection trigger circuit 4, the other end of the resistor R7 is connected to the collector of the transistor Q3, the emitter of the transistor Q3 is connected to the 3.3V power supply 9, the base of the transistor Q3 is connected to the microcontroller MCU8 through the resistor R5, and one end of the resistor R7 is connected to the microcontroller MCU8.

[0025] like Figure 2 As shown, transistor Q3 is a PNP transistor.

[0026] like Figure 2 As shown, the short-circuit protection trigger circuit 4 includes a transistor Q4, a diode D2, and a resistor R12. The collector of the transistor Q4 is connected to the DCDC module 5 and the charging switch circuit 6. The emitter of the transistor Q4 is connected to the DCDC opening circuit 3. The base of the transistor Q4 is connected to one end of the resistor R12 through the diode D2, and the other end of the resistor R12 is connected to the collector of the transistor Q4. The transistor Q4 is a PNP transistor.

[0027] like Figure 2 As shown, the DCDC module 5 includes a DCDC chip U1, a capacitor C2, a capacitor C3, a diode D4, and an inductor L1. The input end IN of the DCDC chip U1 is connected to one end of the capacitor C3 through the capacitor C2, and the other end of the capacitor C3 is connected to the ground signal GND. The output end OUT of the DCDC chip U1 is connected to the ground signal GND through the diode D4, and the output end OUT of the DCDC chip U1 is connected to the microcontroller MCU8 through the inductor L1.

[0028] like Figure 2As shown, the charging switch circuit 6 includes a diode D1, a diode D3, a diode D5, a resistor R9, a resistor R10, a resistor R11, a resistor R14, a voltage stabilizing diode ZD3, a transistor Q7, a MOS transistor Q5, a MOS transistor Q6, a large capacitor C1, and a large capacitor C4. The positive electrode of the diode D1 is connected to the input Vin7, the negative electrode of the diode D1 is connected to the undervoltage shutdown circuit 1, the negative electrode of the diode D1 is connected to the collector of the transistor Q7 through the diode D3, the collector of the transistor Q7 is connected to the overvoltage clamping circuit 2, the collector of the transistor Q7 is connected to the base of the transistor Q7 through the diode D5, the emitter of the transistor Q7 is connected to one end of the large capacitor C1 through the resistor R14, and the other end of the large capacitor C1 is connected to the overvoltage clamping circuit 2 through the diode D5. The large capacitor C4 is connected to the ground signal GND, the emitter of the transistor Q7 is connected to the D pole of the MOS transistor Q6, the G pole of the MOS transistor Q6 is connected to one end of the resistor R9, the other end of the resistor R9 is connected to the DCDC opening circuit 3, the S pole of the MOS transistor Q6 is connected to the D pole of the MOS transistor Q5, the S pole of the MOS transistor Q5 is connected to the short-circuit protection trigger circuit 4 and the DCDC module 5, the G pole of the MOS transistor Q5 is connected to one end of the resistor R9 through the resistor R10, the G pole of the MOS transistor Q5 is connected to the S pole of the MOS transistor Q5 through the voltage regulator diode ZD3, the resistor R11 is connected in parallel with the voltage regulator diode ZD3, the transistor Q7 is an NPN transistor, and the MOS transistor Q5 and the MOS transistor Q6 are both N-channel MOS transistors.

[0029] Working principle:

[0030] 1: When the input voltage VCC is lower than a certain level, the voltage of resistor R3 is lower than 0.7, which is determined by the voltage division of resistors R1, R2 and R3. The gate of MOS tube Q2 is pulled up and turned on by R4, causing G1A in G1 of the optocoupler to not get current and turn off. At this time, the DCDC module is turned off, realizing the undervoltage shutdown function. 2: When the input overvoltage VCC exceeds 93V, the Zener diodes ZD1 and ZD2 are clamped, causing the control end of the input to MOS tube Q5 and MOS tube Q6 to be clamped, realizing the linear step-down function, Q5 and Q6 are turned on, and the DCDC module works normally. 3: When the input is short-circuited for some reason (such as welding short-circuit, tin slag falling, short-circuit before power off, etc.), resistor R12 and diode D2 are short-circuited to GND, and transistor Q4 is turned on. At this time, even if the MCU outputs a high level through resistor R5 and transistor Q3, the primary signal of the optocoupler G1 will be short-circuited, resulting in no current cutoff in the primary of the optocoupler G1, and the DCDC module is turned off, realizing the short-circuit protection function. 4: When the present invention is powered on for the first time, resistor R14 limits the current to charge capacitors C1 and C4. Generally, the present invention will never be powered off after powering on. At this time, since capacitors C1 and C4 are already full, even if MOS tubes Q5 and Q6 are turned on to share power to the next stage, there will be no impact, and the DCDC module will work normally at this time. 5: When the above protections do not occur and the system is working normally, the MCU only needs to output a high level through the resistor R5 transistor Q3, and the transistor Q3 will be turned on. 3V will be sent to the primary of the optocoupler G1, and the MOS tubes Q5 and Q6 will be turned on. Due to the bidirectional conduction principle of the MOS tube, even if the back end is heavily loaded, it can quickly charge and discharge energy through Q5 and Q6, and the DCDC module will work normally.

[0031] 1: With deep undervoltage shutdown function, the present invention can shut down by itself normally, but the premise is that the control loop is normal, so it is necessary to add a hardware shutdown. 2: Deep undervoltage itself needs to have low power consumption requirements, and this circuit meets the requirements. When designing resistors R1, R2, and R3, a total resistance of about 10M is used in series. Then when 20 strings are fully charged at 84V, the leakage is 8.4uA, which has almost no effect on the battery cell. Since MOS is voltage-driven and does not require a large maintenance current, resistor R4 can also use an M-level resistor, and the power supply of resistor R4 is 3.3V, the voltage is low, the resistance is large, and the current consumption is smaller, which meets the continuous maintenance shutdown after undervoltage. 3: With overvoltage clamping function, the DCDC module adopts energy transfer, so the current on the high-voltage side is generally not large, and most of the needs can be met within the range of 20mA. When the external short circuit of the present invention occurs, the input Vin voltage will be raised by the inductive energy. Although Vin is 56-84V under normal system operation, it may soar to 110-120V. At this time, ZD1 and ZD2 voltage regulator tubes are turned on and clamped to 75+18V=93V, R8 current limiting voltage regulator tube current value. When G1B of the optocoupler G1 is turned on, the control level of Q5 and Q6 will be maintained at 93V. At this time, the input level of Q5 and Q6 is greater than the control level, and cannot be fully turned on and are in the linear conduction area. The instantaneous power consumption is (120-93V) 0.02A=0.54W. If Q5 and Q6 use SOT23-3, they can also withstand the instantaneous power. 4: With input short circuit protection and MCU alarm, due to high safety requirements, even if the device is damaged for various reasons, it cannot cause continuous heating, so it is very important to close the problematic circuit in time. When the input of the DCDC module is short-circuited, it will cause a large current and damage the previous stage. This failure model may be just a misoperation and can be recovered. If it is not protected, it will inevitably cause the device to be replaced. If the tin slag falls off and the patch is short-circuited, it can be restored by cleaning without incurring the time and hardware cost of replacing the device. After the short circuit protection, the software and hardware can intervene at the same time. 5: Most of the input capacitors of DCDC modules are directly connected to the chip input end, and can be replenished in time when the back-end is overloaded. However, each switch will cause conduction loss to the switch. If the margin is not enough, it may cause damage, resulting in the inability to shut down the DCDC module loop and continuous discharge, thus only triggering the deep undervoltage function. Experiments show that large capacitors C1 and C4 can be placed before switch Q5. As long as the routing is reasonable so that the distance to the chip after passing the switch is good, the performance will not be compromised. Therefore, this design is adjusted to this method based on experience and requires the layout routing to be 2mm wide and the length to be reduced, so that only R14 and Q7 can withstand one impact when they are powered on for the first time. After normal operation, the capacitor charging and discharging directly passes through Q5 and Q6 without affecting the energy storage function.6: High-end dual Q5 and Q6 N tubes are used for switching and fast charging and discharging. They have small internal resistance and large overcurrent capacity, so they withstand large stress and are not easily damaged. When Q5 is damaged, Q6 can still maintain its function. 7: The driver uses optocoupler isolation to enable, which is safer to use.

[0032] The present invention has deep undervoltage shutdown and short-circuit protection functions. Deep undervoltage has the advantage of low power consumption. The present invention has an overvoltage clamping function. The present invention has an input short-circuit protection function and an MCU alarm function. The present invention uses high-end MOS tubes Q5 and Q6 for switching and fast charging and discharging. The internal resistance is small and the overcurrent capacity is large. Therefore, the stress is large and it is not easy to be damaged. When the MOS tube Q5 is damaged, the MOS tube Q6 can also maintain its function. The driver adopts optical coupling isolation to enable, which greatly improves the safety.

[0033] It should be noted that the above is only a specific embodiment of the present invention. Obviously, the present invention is not limited to the above embodiment, and there are many variations. In short, all variations that can be directly derived or associated with the content disclosed by ordinary technicians in this field should be considered as the protection scope of the present invention.

Claims

1. A DCDC enabling circuit with multiple protections, characterized in that: The invention comprises an undervoltage shutdown circuit (1), an overvoltage clamp circuit (2), a DCDC opening circuit (3), a short circuit protection trigger circuit (4), a DCDC module (5), a charging switch circuit (6), a single chip microcomputer MCU (8), an input Vin (7), and a 3.3V power supply (9). The undervoltage shutdown circuit (1), the overvoltage clamp circuit (2), the DCDC opening circuit (3), the short circuit protection trigger circuit (4), and the DCDC module (5) are all connected to the charging switch circuit (6). The undervoltage shutdown circuit (1), the short circuit protection trigger circuit (4), and the overvoltage clamp circuit (2) are all connected to the DCDC opening circuit (3). The short circuit protection trigger circuit (4) is connected to the DCDC module (5). The DCDC opening circuit (3) and the DCDC module (5) are all connected to the single chip microcomputer MCU (8). The charging switch circuit (6) is connected to the input Vin (7). The undervoltage shutdown circuit (1) and the DCDC opening circuit (3) are all connected to the 3.3V power supply (9). The undervoltage shutdown circuit (1) comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a transistor Q1, and a MOS transistor Q2, one end of the resistor R1 is connected to a charging switch circuit (6), the other end of the resistor R1 is connected to one end of the resistor R3 through the resistor R2, the other end of the resistor R3 is connected to a ground signal GND, one end of the resistor R3 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is connected to the ground signal GND, the collector of the transistor Q1 is connected to a 3.3V power supply (9) through the resistor R4, the G pole of the MOS transistor Q2 is connected to the collector of the transistor Q1, the S pole of the MOS transistor Q2 is connected to the ground signal GND, and the G pole of the MOS transistor Q2 is connected to a DCDC opening circuit (3); The overvoltage clamping circuit (2) comprises a resistor R8, a voltage zener diode ZD1, and a voltage zener diode ZD2, one end of the resistor R8 is connected to a charging switch circuit (6), the other end of the resistor R8 is connected to a DCDC opening circuit (3), the other end of the resistor R8 is connected to a cathode of the voltage zener diode ZD2 via the voltage zener diode ZD1, and the anode of the voltage zener diode ZD2 is connected to a ground signal GND; The DCDC opening circuit (3) comprises an optical coupler G1, a resistor R5, a resistor R6, a resistor R7, and a transistor Q3, wherein pin 2 of the optical coupler G1 is connected to a ground signal GND, pin 1 of the optical coupler G1 is connected to an undervoltage closing circuit (1), pin 4 of the optical coupler G1 is connected to an overvoltage clamping circuit (2), pin 3 of the optical coupler G1 is connected to a charging switch circuit (6), pin 1 of the optical coupler G1 is connected to one end of a resistor R7 through a resistor R6, one end of the resistor R7 is connected to a short-circuit protection trigger circuit (4), the other end of the resistor R7 is connected to the collector of the transistor Q3, the emitter of the transistor Q3 is connected to a 3.3V power supply (9), the base of the transistor Q3 is connected to a single-chip microcomputer MCU (8) through a resistor R5, and one end of the resistor R7 is connected to the single-chip microcomputer MCU (8); The short-circuit protection trigger circuit (4) comprises a transistor Q4, a diode D2, and a resistor R12; the collector of the transistor Q4 is connected to a DCDC module (5) and a charging switch circuit (6); the emitter of the transistor Q4 is connected to a DCDC opening circuit (3); the base of the transistor Q4 is connected to one end of the resistor R12 via the diode D2; and the other end of the resistor R12 is connected to the collector of the transistor Q4; The charging switch circuit (6) comprises a diode D1, a diode D3, a diode D5, a resistor R9, a resistor R10, a resistor R11, a resistor R14, a voltage stabilizing diode ZD3, a transistor Q7, a MOS transistor Q5, a MOS transistor Q6, a large capacitor C1, and a large capacitor C4. The positive electrode of the diode D1 is connected to the input Vin (7), the negative electrode of the diode D1 is connected to the undervoltage shutdown circuit (1), the negative electrode of the diode D1 is connected to the collector of the transistor Q7 through the diode D3, the collector of the transistor Q7 is connected to the overvoltage clamping circuit (2), the collector of the transistor Q7 is connected to the base of the transistor Q7 through the diode D5, the emitter of the transistor Q7 is connected to one end of the large capacitor C1 through the resistor R14, and the other end of the large capacitor C1 is connected to the overvoltage clamping circuit (2). The large capacitor C4 is connected to the ground signal GND, the emitter of the transistor Q7 is connected to the D pole of the MOS transistor Q6, the G pole of the MOS transistor Q6 is connected to one end of the resistor R9, the other end of the resistor R9 is connected to the DCDC opening circuit (3), the S pole of the MOS transistor Q6 is connected to the D pole of the MOS transistor Q5, the S pole of the MOS transistor Q5 is connected to the short-circuit protection trigger circuit (4) and the DCDC module (5), the G pole of the MOS transistor Q5 is connected to one end of the resistor R9 through the resistor R10, the G pole of the MOS transistor Q5 is connected to the S pole of the MOS transistor Q5 through the voltage stabilizing diode ZD3, the resistor R11 is connected in parallel with the voltage stabilizing diode ZD3, the transistor Q7 is an NPN transistor, and the MOS transistors Q5 and Q6 are both N-channel MOS transistors.

2. A DCDC enabling circuit with multiple protections according to claim 1, characterized in that: The MOS transistor Q2 is an N-channel MOS transistor, and the transistor Q1 is an NPN transistor.

3. The DCDC enabling circuit with multiple protections according to claim 1, characterized in that: The transistor Q3 is a PNP transistor.

4. The DCDC enabling circuit with multiple protections according to claim 1, characterized in that: The transistor Q4 is a PNP transistor.

5. The DCDC enabling circuit with multiple protections according to claim 1, characterized in that: The DCDC module (5) comprises a DCDC chip U1, a capacitor C2, a capacitor C3, a diode D4, and an inductor L1; an input terminal IN of the DCDC chip U1 is connected to one end of the capacitor C3 via the capacitor C2, the other end of the capacitor C3 is connected to a ground signal GND, an output terminal OUT of the DCDC chip U1 is connected to the ground signal GND via the diode D4, and an output terminal OUT of the DCDC chip U1 is connected to a single-chip microcomputer MCU (8) via the inductor L1.

Images