Power supply circuit, power supply method and vehicle of electronic control unit

Abstract

The present invention discloses a power supply circuit, a power supply method and a vehicle of an electronic control unit, which relate to the field of automotive electronic control technology and can improve the reliability of the electronic control unit by using a simple circuit structure. The invention comprises: a processor and a plurality of isolation circuits, each isolation circuit comprising a protection circuit and a first switch circuit having a connection relationship. The processor is used to connect to a power supply end, and the processor is also used to connect each functional module in a functional module group, and each functional module is redundant with each other. The first switch circuit in the isolation circuit is used to connect to one of the functional modules in the functional module, and the protection circuit in the isolation circuit is used to connect to the power supply end. The protection circuit is used to control the conduction or disconnection of the corresponding first switch circuit according to the relationship between the current of any functional module and the preset current, so as to ensure that the power supply end continues to supply power to the processor and other functional modules, so that the electronic control unit can work normally.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile electronic control, and in particular to a power supply circuit and a power supply method of an electronic control unit and a vehicle. Background Art

[0002] In traditional electronic control units, a power management IC (PMIC) is used to connect the vehicle's battery and various functional modules. That is, the battery can supply power to different functional modules at the same time through a voltage management chip. However, the reliability of each functional module is different. Once a power supply failure occurs in the power supply branch where one functional module is located, the power supply branches where other functional modules are located will also fail. This results in low reliability of traditional electronic control units.

[0003] In the related art, in order to improve the reliability of the electronic control unit, a redundant design is adopted to divide each functional module according to the safety level requirements, and divide the functional modules with the same safety level requirements and functions into a group. In addition, a group of functional modules is connected to the power supply end of the vehicle through a PMIC. In this way, when a functional module on a PMIC branch fails to supply power, other PMIC branches can still supply power normally, so that the electronic control unit can maintain some or even all functions.

[0004] However, the electronic control unit with redundant design has a complex structure, high cost, large size and weight, and when a functional module on a PMIC branch has a power supply failure, other functional modules on the branch will also have power supply failures. In other words, the reliability of the electronic control unit obtained by redundant design still cannot meet the requirements. Summary of the invention

[0005] The present invention provides a power supply circuit, a power supply method and a vehicle of an electronic control unit, which can improve the reliability of the electronic control unit by adopting a simple circuit structure.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme:

[0007] In a first aspect, the present invention provides a power supply circuit for an electronic control unit, the power supply circuit comprising: a processor and a plurality of isolation circuits, each isolation circuit comprising a protection circuit and a first switch circuit having a connection relationship. The processor is used to connect to a power supply terminal, and the processor is also used to connect to each functional module in a functional module group, and each functional module is redundant to each other. The first switch circuit in the isolation circuit is used to connect to one of the functional modules in the functional module group, and the protection circuit in the isolation circuit is used to connect to the power supply terminal.

[0008] The protection circuit is used to turn on the first switch circuit corresponding to the first functional module when the current of the first functional module is less than or equal to the preset current, so that the power supply end supplies power to the first functional module; and is also used to turn off the first switch circuit corresponding to the first functional module when the current of the second functional module is greater than the preset current, so that the power supply end is isolated from the second functional module, and the power supply end continues to supply power to the processor and other functional modules in the functional module group. The first functional module and the second functional module are any one of the functional modules in the functional module group.

[0009] In actual application, when the current of the first functional module is less than or equal to the preset current, the protection circuit can turn on the first switch circuit corresponding to the first functional module, so that the power supply end can supply power to the first functional module in the functional module group through the protection circuit and the first switch circuit. When the current of the second functional module is greater than the preset current, it indicates that the power supply end of the second functional module has a short circuit to ground, low impedance and other faults, and the protection circuit can turn off the first switch circuit corresponding to the second functional module, so that the second functional module can be isolated from the power supply end, so as not to affect the power supply end to the other functional modules and processors in the functional module group. Since the functional modules in the functional module group are redundant, when the second functional module fails, the other functional modules and processors in the functional module group can still work normally, then the processor can continue to receive the electrical signals of other functional modules in the functional module group, and process the electrical signals, so that the electronic control unit works normally, thereby improving the reliability of the electronic control unit.

[0010] In a possible implementation, the power supply circuit of the electronic control unit further includes a voltage management chip. The voltage management chip is used to be connected to the power supply terminal, and the voltage management chip is also connected to each isolation circuit and the processor.

[0011] In a possible implementation, the first switch circuit includes: a first transistor and a first resistor. The base of the first transistor is connected to the first end of the first resistor and the protection circuit, the emitter is connected to the second end of the first resistor and the protection circuit, and the collector is used to connect a functional module.

[0012] The first transistor is a PNP transistor.

[0013] In a possible implementation, the protection circuit is a mirror circuit.

[0014] In a possible implementation, the mirror circuit includes: a second switch circuit and a third switch circuit. The second switch circuit is used to connect to the power supply terminal, and the second switch circuit is connected to the collector of the first transistor and the third switch circuit. The third switch circuit is used to connect to the power supply terminal, and the third switch circuit is connected to the emitter of the first transistor.

[0015] In a possible implementation, the second switch circuit includes: a second triode, a second resistor, and a third resistor. The first end of the second resistor is used to be connected to the power supply end, and the second end of the second resistor is connected to the emitter of the second triode. The base of the second triode is connected to the third switch circuit, and the collector is connected to the first end of the third resistor and the base of the first triode. The second end of the third resistor is used to be connected to the ground end.

[0016] The second transistor is a PNP transistor, and the first transistor and the second transistor are of the same model.

[0017] In a possible implementation, the third switch circuit includes: a third triode, a fourth resistor and a fifth resistor. The first end of the fourth resistor is used to be connected to the power supply end, the second end of the fourth resistor is connected to the emitter of the first triode and the emitter of the third triode; the base and collector of the third triode are connected to the base of the second triode, and the collector of the third triode is also connected to the first end of the fifth resistor; the second end of the fifth resistor is used to be connected to the ground end.

[0018] The ratio of the second resistor to the third resistor and the ratio of the fourth resistor to the fifth resistor meet the preset conditions. The second transistor is a PNP transistor.

[0019] In a second aspect, the present invention provides a power supply method for an electronic control unit, the power supply method comprising:

[0020] When the current of the first functional module is less than or equal to the preset current, the protection circuit turns on the first switch circuit corresponding to the first functional module, so that the power supply end supplies power to the first functional module;

[0021] When the current of the second functional module is greater than the preset current, the protection circuit turns off the first switch circuit corresponding to the second functional module, thereby isolating the power supply end from the second functional module, and the power supply end continues to supply power to the processor and other functional modules in the functional module group; the first functional module and the second functional module are any one of the functional modules in the functional module group.

[0022] In a possible implementation, when the current of the first functional module is less than or equal to a preset current, the protection circuit turns on the first switch circuit corresponding to the first functional module, including:

[0023] When the current of the collector of the first triode is less than or equal to the preset current, the protection circuit makes the difference between the voltage of the emitter and the voltage of the base of the first triode equal to the emitter junction voltage of the first triode, and the first triode is turned on;

[0024] The protection circuit turns off the first switch circuit corresponding to the second functional module when the current of the protection circuit in the second functional module is greater than the preset current, including:

[0025] When the current of the collector of the first triode is greater than the preset current, the protection circuit makes the difference between the voltage of the emitter and the voltage of the base of the first triode smaller than the emitter junction voltage of the first triode, and the first triode is turned off;

[0026] The first transistor is a PNP transistor.

[0027] In a third aspect, the present invention provides a vehicle, comprising a power supply circuit of an electronic control unit according to the first aspect and any possible implementation thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is one of the structural schematic diagrams of the power supply circuit of the electronic control unit in the prior art;

[0029] Figure 2 The second structural schematic diagram of the power supply circuit of the electronic control unit in the prior art;

[0030] Figure 3 One of the structural schematic diagrams of the power supply circuit of the electronic control unit provided in an embodiment of the present invention;

[0031] Figure 4 A second structural schematic diagram of a power supply circuit of an electronic control unit provided in an embodiment of the present invention;

[0032] Figure 5 Schematic diagram of the structure of the isolation circuit in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "multiple" means two or more. In addition, the use of "based on" or "according to" means openness and inclusiveness, because the process, steps, calculations or other actions "based on" or "according to" one or more of the conditions or values ​​may be based on additional conditions or values ​​beyond the described values ​​in practice.

[0035] Figure 1 FIG. 1 shows one of the structural schematic diagrams of the power supply circuit of the electronic control unit in the prior art. Figure 1 As shown, the power supply circuit of the electronic control unit in the prior art includes a voltage management chip 100 and a processor 200. One end of the voltage management chip 100 is used to connect to the power supply end, and the other end of the voltage management chip is used to directly connect to each functional module and the processor 200, and each functional module is also connected to the processor 200. Among them, the power supply end can be a battery of a vehicle, and the functions of each functional module are different.

[0036] After the power supply end outputs the voltage through the voltage management chip 100, it directly supplies power to each functional module and the processor 200. After each functional module is powered on, it provides a corresponding electrical signal to the processor 200. The processor 200 processes the electrical signals provided by each functional module to enable the electronic control unit to operate normally. However, since each functional module and the processor 200 are directly connected to the voltage management chip 100, when a short circuit or other fault occurs in one of the functional modules, causing the power supply of the functional module to fail, other functional modules and the processor 200 will also have power supply failure problems, thereby making the electronic control unit unable to operate normally. In other words, such a power supply circuit makes the reliability of the electronic control unit very low.

[0037] Figure 2 FIG2 shows a second structural schematic diagram of a power supply circuit of an electronic control unit in the prior art. Figure 2As shown, in response to the above technical problems, the power supply circuit of the electronic control unit in another prior art includes: a processor 200 and a plurality of voltage management chips 100. One end of each voltage management chip 100 is used to connect to the power supply end, and the other end of each voltage management chip 100 is directly connected to each functional module in a functional module group, or connected to the processor 200. The safety level of each functional module included in a functional module group in the prior art is the same. That is to say, in order to improve the reliability of the electronic control unit in another prior art, the voltage management chip 100 is redundantly designed. When the power supply of any functional module connected to one of the voltage management chips 100 fails, the other functional modules connected to the voltage management chip 100 will also have a power supply failure problem. However, the functional modules or processors 200 connected to other voltage management chips 100 are powered normally, so that some functions of the electronic control unit can still be used normally.

[0038] It should be noted that Figure 2 In the figure, a functional module group including a functional module 1 and a functional module 2 having the same security level is taken as an example.

[0039] It can be seen that such a power supply circuit still makes the reliability of the electronic control unit low and cannot meet the requirements. In order to improve the reliability of the electronic control unit, an embodiment of the present invention provides a power supply circuit for an electronic control unit.

[0040] Figure 3 FIG. 1 shows one of the structural schematic diagrams of the power supply circuit of the electronic control unit provided by an embodiment of the present invention. Figure 3 As shown, the power supply circuit of the electronic control unit provided in the embodiment of the present invention may include: a processor 200 and a plurality of isolation circuits 300, each isolation circuit 300 including a protection circuit 310 and a first switch circuit 320 having a connection relationship. The processor 200 is used to connect to the power supply end, and the processor 200 is also used to connect each functional module in the functional module group, and each functional module is redundant. The first switch circuit 320 in the isolation circuit 300 is used to connect to one of the functional modules in the functional module group, and the protection circuit 310 in the isolation circuit 300 is used to connect to the power supply end.

[0041] The protection circuit 310 is used to turn on the first switch circuit 320 corresponding to the first functional module when the current of the first functional module is less than or equal to the preset current, so that the power supply end supplies power to the first functional module; and is also used to turn off the first switch circuit 320 corresponding to the second functional module when the current of the second functional module is greater than the preset current, so that the power supply end is isolated from the second functional module, and the power supply end continues to supply power to the processor 200 and other functional modules in the functional module group. The first functional module and the second functional module are any one of the functional modules in the functional module group.

[0042] It should be noted that Figure 3 It is illustrated by taking an example that the power supply circuit of the electronic control unit includes a functional module group, and the functional module group includes a functional module 11 and a functional module 12 which are redundant to each other.

[0043] In actual application, when the current of the first functional module is less than or equal to the preset current, the current of the protection circuit is less than or equal to the current threshold, and the protection circuit can turn on the first switch circuit, so that the power supply end can supply power to the first functional module in the functional module group through the protection circuit and the first switch circuit. When the current of the second functional module is greater than the preset current, it indicates that the second functional module has a short circuit to ground, a low impedance, and other faults, so that the current of the protection circuit is greater than the current threshold, and the protection circuit turns off the first switch circuit, so that the second functional module can be isolated from the power supply end, so as not to affect the power supply end to other functional modules and processors in the functional module group. Since the functional modules in the functional module group are redundant, when the second functional module fails, the other functional modules and processors in the functional module group can still work normally, so the processor can continue to receive the electrical signals of other functional modules in the functional module group and process the electrical signals, so that the electronic control unit works normally, thereby improving the reliability of the electronic control unit.

[0044] Optional, such as Figure 3 As shown, the power supply circuit of the electronic control unit provided in the embodiment of the present invention further includes a voltage management chip 100. The voltage management chip 100 is used to connect to the power supply terminal, and the voltage management chip 100 is also connected to each isolation circuit 300 and the processor 200.

[0045] Since each functional module in the functional module group is provided with an isolation circuit on the power supply circuit of the power supply end, it is ensured that the electronic control unit can work normally when one of the functional modules fails. Therefore, the electronic control unit provided in the embodiment of the present invention can include only one voltage management chip 100. Compared with the prior art in which the voltage management chip 100 is redundantly designed to improve the reliability of the electronic control unit, the reliability of the electronic control unit is higher and the production cost is greatly reduced.

[0046] Figure 4 A second structural schematic diagram of a power supply circuit of an electronic control unit provided in an embodiment of the present invention is shown.

[0047] Optional, combined Figure 3 ,like Figure 4As shown, the first switch circuit 320 may include: a first transistor Q1 and a first resistor R1. The base of the first transistor Q1 is connected to the first end of the first resistor R1 and the protection circuit 310, the emitter is connected to the second end of the first resistor R1 and the protection circuit 310, and the collector is used to connect a functional module. The first transistor Q1 is a PNP transistor.

[0048] In actual application, Figure 4 As shown, when the current of the collector of the first transistor Q1 is less than or equal to the preset current, the protection circuit can turn on the first transistor Q1, so that after the power supply end outputs the voltage through the voltage management chip 100, the protection circuit and the first transistor Q1 can supply power to the corresponding functional module in the functional module group. When the current of the collector of the first transistor Q1 is greater than the preset current, it indicates that the corresponding functional module in the functional module group has a short circuit to the ground, a low impedance, and other faults. The protection circuit can turn off the first transistor Q1, so that the corresponding functional module in the functional module group is isolated from the voltage management chip, so as not to affect the power supply circuit of other functional modules and the processor in the functional module group, so that the power supply end continues to supply power to the processor and other functional modules in the functional module group through the voltage management chip.

[0049] Optionally, the protection circuit may be a mirror circuit.

[0050] Figure 5 A schematic structural diagram of an isolation circuit provided by an embodiment of the present invention is shown.

[0051] Optional, combined Figure 4 ,like Figure 5 As shown, the mirror circuit may include: a second switch circuit 3101 and a third switch circuit 3102. The second switch circuit 3101 is used to connect to the power supply terminal, and the second switch circuit 3101 is connected to the base of the first transistor Q1 and the third switch circuit 3102. The third switch circuit 3102 is used to connect to the power supply terminal, and the third switch circuit 3102 is connected to the emitter of the first transistor Q1.

[0052] The second switch circuit provides a voltage to the base of the first transistor Q1, and the third switch circuit provides a voltage to the emitter of the first transistor Q1. When the functional module connected to the collector of the first transistor Q1 is normal, that is, the current of the collector of the first transistor Q1 is less than or equal to the preset current, the voltage provided by the third switch circuit is greater than the voltage provided by the second switch circuit, and the difference between the voltage provided by the third switch circuit and the voltage provided by the second switch circuit is the emitter junction voltage of the first transistor. The first transistor Q1 is a PNP transistor, so the first transistor Q1 is turned on, and the power supply end supplies power to the functional module connected to the collector of the first transistor Q1. When the functional module connected to the collector of the first transistor Q1 has a fault such as a short circuit to the ground, that is, the current of the collector of the first transistor Q1 is greater than the preset current, the difference between the voltage provided by the third switch circuit and the voltage provided by the second switch circuit will be less than the emitter junction voltage of the first transistor, so that the first transistor Q1 is turned off, and the functional module connected to the collector of the first transistor Q1 is isolated from the power supply end.

[0053] For example, Figure 5 As shown, the second switch circuit 3101 may include: a second transistor Q2, a second resistor R2 and a third resistor R3. The first end of the second resistor R2 is used to be connected to the power supply end, and the second end of the second resistor R2 is connected to the emitter of the second transistor Q2. The base of the second transistor Q2 is connected to the third switch circuit 3102, and the collector is connected to the first end of the third resistor R3 and the base of the first transistor Q1. The second end of the third resistor R3 is used to be connected to the ground end. The second transistor Q2 is a PNP transistor, and the first transistor and the second transistor are of the same model.

[0054] For example, Figure 5 As shown, the third switch circuit 3102 may include: a third transistor Q3, a fourth resistor R4 and a fifth resistor R5. The first end of the fourth resistor R4 is used to be connected to the power supply end, and the second end of the fourth resistor R4 is connected to the emitter of the first transistor Q1 and the emitter of the third transistor Q3. The base and collector of the third transistor Q3 are connected to the base of the second transistor Q2, and the collector of the third transistor Q3 is also connected to the first end of the fifth resistor R5. The second end of the fifth resistor R5 is used to be connected to the ground end. The ratio of the second resistor R2 to the third resistor R3 and the ratio of the fourth resistor R4 to the fifth resistor R5 meet the preset conditions. And the second transistor Q2 is a PNP transistor.

[0055] It should be noted that the ratio of the fourth resistor R4 to the fifth resistor R5 is slightly greater than the ratio of the second resistor R2 to the third resistor R3. Generally, the two ratios can be considered to be the same.

[0056] Since the second transistor Q2 and the third transistor Q3 are two transistors constituting the mirror circuit, the second transistor Q2 and the third transistor Q3 are PNP transistors of the same model. The first transistor Q1 is of the same model as the second transistor Q2, so the first transistor Q1, the second transistor Q2 and the third transistor Q3 are of the same model. Then, Ueb(Q2)=Ueb(Q3), Uec(Q2)=Uec(Q3). Since the base of the first transistor Q1 is connected to the collector of the second transistor Q2, the base of the third transistor Q3 is connected to the collector and the base of the second transistor Q2, and the ratio of the fourth resistor R4 to the fifth resistor R5 is the same as the ratio of the second resistor R2 to the third resistor R3. Therefore, the voltage relationship between the emitter and the base of the first transistor Q1 can be expressed by the following formula (1).

[0057] Ub(Q1)=Uc(Q2)=Ue(Q3)-Ueb(Q3)=Ue(Q1)-Ueb(Q1) (1)

[0058] It can be seen that the emitter voltage Ue(Q1) of the first transistor Q1 is greater than the base voltage Ub(Q1), and the difference between the two is the emitter junction voltage Ueb(Q1) of the first transistor Q1, so the first transistor Q1 is turned on. When the voltage of the collector of the first transistor Q1 is zero, that is, when the power supply end of the corresponding functional module is short-circuited to the ground, the current flowing through the first transistor Q1 increases, while the current flowing through the second transistor Q2 and the third transistor Q3 remains unchanged, so the current flowing through the fourth resistor R4 increases. The increase in the current flowing through the fourth resistor R4 will cause the voltage drop of the fourth resistor R4 to increase, thereby causing the voltage of the emitter of the first transistor Q1 and the emitter of the third transistor Q3 to decrease, while the voltage of the collector of the second transistor Q2 remains unchanged, that is, the voltage of the base of the first transistor Q1 remains unchanged. Then according to formula (1), it can be obtained that the difference between the emitter voltage Ue(Q1) and the base voltage Ub(Q1) of the first transistor Q1 is less than the emitter junction voltage Ueb(Q1) of the first transistor Q1, so that the first transistor Q1 cannot continue to be turned on, that is, the first transistor Q1 is turned off, and the corresponding functional module is isolated from the power supply end, thereby not affecting the power supply end to other functional modules and processors.

[0059] Optionally, the current of the mirror circuit may be adjusted by adjusting the ratio of the fourth resistor R4 to the fifth resistor R5 and the ratio of the second resistor R2 to the third resistor R3.

[0060] On the other hand, an embodiment of the present invention further provides a power supply method for an electronic control unit. The power supply method for an electronic control unit may include the following steps:

[0061] When the current of the first functional module is less than or equal to the preset current, the protection circuit turns on the first switch circuit corresponding to the first functional module, so that the power supply end supplies power to the first functional module;

[0062] When the current of the second functional module is greater than the preset current, the protection circuit turns off the first switch circuit corresponding to the second functional module, thereby isolating the power supply end from the second functional module, and the power supply end continues to supply power to the processor and other functional modules in the functional module group; the first functional module and the second functional module are any one of the functional modules in the functional module group.

[0063] Specifically, when the current of the first functional module is less than or equal to the preset current, the protection circuit turns on the first switching circuit corresponding to the first functional module, which may include: when the current of the collector of the first transistor is less than or equal to the preset current, the protection circuit makes the difference between the voltage of the emitter and the voltage of the base of the first transistor equal to the emitter junction voltage of the first transistor, and the first transistor is turned on.

[0064] Specifically, when the current of the second functional module is greater than the preset current, the protection circuit turns off the first switching circuit corresponding to the second functional module, which may include: when the current of the collector of the first transistor is greater than the preset current, the protection circuit makes the difference between the voltage of the emitter and the voltage of the base of the first transistor smaller than the emitter junction voltage of the first transistor, and the first transistor is turned off.

[0065] In another aspect, an embodiment of the present invention further provides a vehicle, which includes the power supply circuit of the electronic control unit.

[0066] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A power supply circuit for an electronic control unit, characterized in that: include: A processor and a plurality of isolation circuits, each of the isolation circuits comprising a protection circuit and a first switch circuit in a connection relationship; The processor is used to connect to the power supply end, and the processor is also used to connect each functional module in the functional module group, and each functional module is redundant with each other; the first switch circuit in the isolation circuit is used to connect to one of the functional modules in the functional module group, and the protection circuit in the isolation circuit is used to connect to the power supply end; The protection circuit is used to turn on the first switch circuit corresponding to the first functional module when the current of the first functional module is less than or equal to the preset current, so that the power supply end supplies power to the first functional module; It is also used to turn off the first switch circuit corresponding to the second functional module when the current of the second functional module is greater than the preset current, so that the power supply end is isolated from the second functional module, and the power supply end continues to supply power to the processor and other functional modules in the functional module group; the first functional module and the second functional module are any one functional module in the functional module group; The protection circuit is a mirror circuit; The first switch circuit includes: a first transistor and a first resistor; The base of the first transistor is connected to the first end of the first resistor and the protection circuit, the emitter is connected to the second end of the first resistor and the protection circuit, and the collector is used to connect to one of the functional modules; The first transistor is a PNP transistor.

2. The power supply circuit of the electronic control unit according to claim 1, characterized in that: The power supply circuit of the electronic control unit also includes a voltage management chip; The voltage management chip is used to be connected to the power supply end, and the voltage management chip is also connected to each of the isolation circuits and the processor.

3. The power supply circuit of the electronic control unit according to claim 2, characterized in that: The mirror circuit comprises: a second switch circuit and a third switch circuit; The second switch circuit is used to be connected to the power supply end, and the second switch circuit is connected to the base of the first transistor and the third switch circuit; The third switch circuit is used to be connected to the power supply end, and the third switch circuit is connected to the emitter of the first transistor.

4. The power supply circuit of the electronic control unit according to claim 3, characterized in that: The second switch circuit includes: a second transistor, a second resistor and a third resistor; The first end of the second resistor is used to be connected to the power supply end, and the second end of the second resistor is connected to the emitter of the second transistor; the base of the second transistor is connected to the third switch circuit, and the collector is connected to the first end of the third resistor and the base of the first transistor; the second end of the third resistor is used to be connected to the ground end; The second transistor is a PNP transistor, and the first transistor and the second transistor are of the same model.

5. The power supply circuit of the electronic control unit according to claim 4, characterized in that: The third switch circuit comprises: a third transistor, a fourth resistor and a fifth resistor; The first end of the fourth resistor is used to be connected to the power supply end, the second end of the fourth resistor is connected to the emitter of the first triode and the emitter of the third triode; the base and collector of the third triode are connected to the base of the second triode, and the collector of the third triode is also connected to the first end of the fifth resistor; the second end of the fifth resistor is used to be connected to the ground end; A ratio of the second resistor to the third resistor and a ratio of the fourth resistor to the fifth resistor meet a preset condition; The second transistor is a PNP transistor.

6. A power supply method for an electronic control unit, characterized in that: The power supply circuit applied to the electronic control unit according to any one of claims 1 to 5, the power supply method comprising: When the current of the first functional module is less than or equal to the preset current, the protection circuit turns on the first switch circuit corresponding to the first functional module, so that the power supply end supplies power to the first functional module; When the current of the second functional module is greater than the preset current, the protection circuit turns off the first switch circuit corresponding to the second functional module, thereby isolating the power supply end from the second functional module, and the power supply end continues to supply power to the processor and other functional modules in the functional module group; the first functional module and the second functional module are any one of the functional modules in the functional module group.

7. The power supply method for an electronic control unit according to claim 6, characterized in that: When the current of the first functional module is less than or equal to a preset current, the protection circuit turns on the first switch circuit corresponding to the first functional module, including: When the current of the collector of the first transistor is less than or equal to the preset current, the protection circuit makes the difference between the voltage of the emitter and the voltage of the base of the first transistor equal to the emitter junction voltage of the first transistor, and the first transistor is turned on; When the current of the second functional module is greater than the preset current, the protection circuit turns off the first switch circuit corresponding to the second functional module, including: When the current of the collector of the first transistor is greater than the preset current, the protection circuit makes the difference between the voltage of the emitter and the voltage of the base of the first transistor smaller than the emitter junction voltage of the first transistor, and the first transistor is turned off; The first transistor is a PNP transistor.

8. A vehicle, characterized in that: A power supply circuit comprising an electronic control unit as claimed in any one of claims 1 to 5.

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