A wheel speed sensor power supply circuit and device for a 48V automotive power supply system

Abstract

This invention discloses a wheel speed sensor power supply circuit and device for a 48V automotive power supply system, belonging to the field of vehicle technology. The power supply circuit includes a voltage detection module, a dedicated chip, a loop control module, a self-locking module, an overvoltage shutdown module, an unlocking module, and an MCU module. The voltage detection module detects the voltage at the power supply terminal of the wheel speed sensor; the loop control module controls the on / off state of the wheel speed sensor current loop; the overvoltage shutdown module disconnects the wheel speed sensor current loop when the voltage at the power supply terminal exceeds a voltage threshold; the self-locking module implements the self-locking control of the overvoltage shutdown module; and the MCU module unlocks the overvoltage shutdown module's self-locking mechanism via the unlocking module after the voltage at the wheel speed sensor's power supply terminal returns to normal. This invention achieves overvoltage protection at the wheel speed sensor's power supply terminal using a purely hardware-based approach, without MCU intervention, and offers a fast response time.

Description

Technical Field

[0001] This invention belongs to the field of vehicle technology, specifically relating to a wheel speed sensor power supply circuit and device for a 48V power supply system for automobiles. Background Technology

[0002] As the automotive industry accelerates its transformation towards electrification and intelligentization, vehicle electrical architecture is undergoing a systemic upgrade from the traditional 12V voltage platform to a 48V voltage platform. Wheel speed sensors are core sensing components of automotive anti-lock braking systems (ABS), electronic stability control (ESC), and autonomous driving perception systems; their functional reliability directly affects vehicle driving safety. Currently, existing wheel speed sensors primarily use the Hall effect principle to detect wheel speed. In terms of power supply, the operating voltage range of existing wheel speed sensors is typically set between 5V and 24V, with a typical supply voltage of 12V, whose upper limit is far lower than the operating voltage of the 48V platform.

[0003] When existing wheel speed sensors are directly applied to a 48V power supply system, the voltage withstand capability of the sensor power supply cannot meet the requirements. The nominal operating voltage of a 48V system is approximately 48V. Considering battery charging and discharging fluctuations and alternator output voltage variations, the actual operating voltage may fluctuate between 36V and 56V. More critically, the 48V automotive electrical environment is subject to severe voltage transients, such as sudden load drops, which can generate transient voltages as high as hundreds of volts. Existing wheel speed sensors typically have a rated operating voltage limit of only 24V and a maximum withstand voltage of no more than 30V, far below the normal operating voltage and transient overvoltage levels of a 48V system. Directly connecting existing wheel speed sensors to a 48V power supply network can easily lead to damage to the internal electronic components of the sensor due to overvoltage, causing sensor failure and jeopardizing the normal operation of safety-critical systems such as ABS and ESC.

[0004] In summary, there is a significant electrical mismatch between the existing power supply voltage design of wheel speed sensors and the 48V power supply system of automobiles, making direct compatibility difficult. Designing a wheel speed sensor power supply solution that can directly adapt to the 48V power supply system and ensure reliability has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] One objective of this invention is to provide a power supply circuit and device for a wheel speed sensor in a 48V automotive power supply system, which can solve the technical problem of mismatch between the power supply voltage design system of the wheel speed sensor and the 48V automotive power supply system in the prior art.

[0006] According to a first aspect of the present invention, a wheel speed sensor power supply circuit for a 48V automotive power supply system is provided, comprising a voltage detection module, a dedicated chip, a loop control module, a self-locking module, an overvoltage shutdown module, an unlocking module, and an MCU module;

[0007] The voltage detection module is connected to the first end of the wheel speed sensor and the MCU module respectively. The first end of the wheel speed sensor is the power supply end of the wheel speed sensor. The voltage detection module is used to detect the voltage of the power supply end of the wheel speed sensor and feed the voltage of the power supply end of the wheel speed sensor back to the MCU module.

[0008] The dedicated chip is connected to the first end of the wheel speed sensor and the MCU module respectively, and the dedicated chip is used to power the wheel speed sensor.

[0009] The loop control module is connected to the second terminal of the wheel speed sensor and the MCU module respectively, and is used to control the on / off state of the wheel speed sensor current loop; when the loop control module is in the first state, the wheel speed sensor current loop is disconnected; when the loop control module is in the second state, the wheel speed sensor current loop is turned on.

[0010] The overvoltage shutdown module is connected to the first terminal of the wheel speed sensor and the loop control module respectively. The overvoltage shutdown module is used to control the loop control module to enter the first state when the voltage at the power supply terminal of the wheel speed sensor exceeds the voltage threshold.

[0011] The self-locking module is connected to the overvoltage shutdown module and the loop control module respectively. The self-locking module is used to realize the self-locking control of the overvoltage shutdown module when the voltage at the power supply terminal of the wheel speed sensor exceeds the voltage threshold, so that the loop control module is maintained in the first state.

[0012] The unlocking module is connected to the MCU module and the overvoltage shutdown module respectively. The MCU module is used to release the self-locking of the overvoltage shutdown module through the unlocking module after the voltage at the power supply terminal of the wheel speed sensor returns to normal, so that the loop control module returns to the second state.

[0013] Optionally, the loop control module includes a first transistor, a first resistor, and a second resistor;

[0014] The collector of the first transistor is connected to the second end of the wheel speed sensor, the emitter of the first transistor is grounded, the base of the first transistor is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the first GIO port of the MCU.

[0015] Optionally, the first transistor is an NPN transistor.

[0016] Optionally, the overvoltage shutdown module includes a second transistor, a third resistor, and a Zener diode;

[0017] The collector of the second transistor is connected to the first end of the second resistor, the emitter of the second transistor is grounded, the base of the second transistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the first end of the wheel speed sensor via the Zener diode.

[0018] Optionally, the second transistor is an NPN transistor.

[0019] Optionally, the self-locking module includes a third transistor, a fourth resistor, and a first diode;

[0020] The emitter of the third transistor is connected to the power supply, the base of the third transistor is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the first end of the second resistor, the collector of the third transistor is connected to the anode of the first diode, and the cathode of the first diode is connected to the second end of the third resistor.

[0021] Optionally, the third transistor is a PNP transistor.

[0022] Optionally, the unlocking module includes a fourth transistor and a fifth resistor;

[0023] The first end of the fifth resistor is connected to the second GIO port of the MCU, the second end of the fifth resistor is connected to the base of the fourth transistor, the emitter of the fourth transistor is grounded, and the collector of the fourth transistor is connected to the base of the second transistor.

[0024] Optionally, the fourth transistor is an NPN transistor.

[0025] According to a second aspect of the present invention, an electronic device is provided, comprising a wheel speed sensor power supply circuit for a 48V automotive power supply system as described in the first aspect of the present invention.

[0026] The advantages of this invention are as follows: This invention implements overvoltage protection at the power supply terminal of the wheel speed sensor using a purely hardware-based approach, without MCU intervention, resulting in a fast response time. Furthermore, self-locking ensures that the wheel speed sensor current loop remains open after the fault voltage disappears, preventing repeated actions that could damage the sensor. The recovery action is actively controlled by the MCU, using a voltage detection module to continuously monitor the voltage at the wheel speed sensor's power supply terminal, ensuring safe recovery. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a wheel speed sensor power supply circuit for a 48V automotive power supply system according to an embodiment of the present invention. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0029] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0030] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0032] In the specification of this invention, the terms "first" and "second" may explicitly or implicitly include one or more of the same feature. In the description of this invention, unless otherwise stated, "multiple" means two or more. Furthermore, in the specification, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0033] like Figure 1 As shown in the figure, this embodiment introduces a wheel speed sensor power supply circuit for a 48V automotive power supply system, including a voltage detection module, a dedicated chip, a loop control module, a self-locking module, an overvoltage shutdown module, an unlocking module, and an MCU module.

[0034] The voltage detection module is connected to the first end of the wheel speed sensor and the MCU module respectively. The first end of the wheel speed sensor is the power supply end of the wheel speed sensor. The voltage detection module is used to detect the voltage of the power supply end of the wheel speed sensor and feed the voltage of the power supply end of the wheel speed sensor back to the MCU module.

[0035] The dedicated chip is connected to the first end of the wheel speed sensor and the MCU module respectively, and the dedicated chip is used to power the wheel speed sensor.

[0036] The loop control module is connected to the second terminal of the wheel speed sensor and the MCU module respectively, and is used to control the on / off state of the wheel speed sensor current loop; when the loop control module is in the first state, the wheel speed sensor current loop is disconnected; when the loop control module is in the second state, the wheel speed sensor current loop is turned on.

[0037] The overvoltage shutdown module is connected to the first end of the wheel speed sensor and the loop control module respectively. The overvoltage shutdown module is used to control the loop control module to enter the first state when the voltage at the power supply end of the wheel speed sensor exceeds the voltage threshold.

[0038] The self-locking module is connected to the overvoltage shutdown module and the loop control module respectively. The self-locking module is used to implement the self-locking control of the overvoltage shutdown module when the voltage at the power supply terminal of the wheel speed sensor exceeds the voltage threshold, so that the loop control module is maintained in the first state.

[0039] The unlocking module is connected to the MCU module and the overvoltage shutdown module respectively. The MCU module is used to release the self-locking of the overvoltage shutdown module through the unlocking module after the voltage at the power supply terminal of the wheel speed sensor returns to normal, so that the loop control module returns to the second state.

[0040] A dedicated chip is used for power supply and signal processing of the wheel speed sensor. It integrates a power management module that converts the high voltage provided by the vehicle's 48V power supply system into the stable voltage required by the wheel speed sensor. For example... Figure 1 As shown, a diode D2 is also placed between the power supply terminal of the dedicated chip and the wheel speed sensor. When a high voltage appears at the power supply terminal of the wheel speed sensor, diode D2 can prevent high voltage backflow. The dedicated chip is connected to the GTM port of the MCU, and the MCU acquires the wheel speed sensor signal and status signal through the GTM port.

[0041] The voltage detection module is connected to both the power supply terminal of the wheel speed sensor and the AD_CH1 port of the MCU (Microcontroller Unit). The module monitors the voltage at the wheel speed sensor's power supply terminal in real time and feeds it back to the MCU module via the AD_CH1 port. The voltage detection module can use a general-purpose solution, such as a resistor divider, or it can use a dedicated detection chip, depending on the specific requirements.

[0042] The MCU module can send different signals to the loop control module to change its state. For example, a low-level signal from the MCU module disconnects the loop control module, putting it into the first state. A high-level signal from the MCU module turns the loop control module on, putting it into the second state.

[0043] Under normal operating conditions, the voltage at the power supply terminal of the wheel speed sensor is within the normal range. At this time, the loop control module is in the second state, forming a current loop with the wheel speed sensor, and the wheel speed sensor current loop is turned on.

[0044] The voltage threshold can be set to the withstand voltage of the wheel speed sensor, such as 30V. When high voltage occurs at the power supply terminal of the wheel speed sensor, i.e., the voltage at the power supply terminal exceeds the voltage threshold (e.g., 48V, exceeding the 30V withstand voltage), the overvoltage shutdown module changes the state of the loop control module from the second state to the first state, thereby shutting off the wheel speed sensor current loop. At this time, although the voltage at the wheel speed sensor's power supply terminal is higher than its withstand voltage, because there is no current loop, the wheel speed sensor becomes an equipotential body, entering a safe state and will not be damaged by the high voltage at the power supply terminal. Simultaneously, a self-locking module maintains the state of the overvoltage shutdown module, achieving self-locking and keeping the loop control module in the first state, with the wheel speed sensor current loop continuously disconnected.

[0045] After the voltage at the power supply terminal of the wheel speed sensor returns to normal, the overvoltage shutdown module is unlocked by the unlocking module. The overvoltage shutdown module no longer keeps the loop control module in the first state, and the loop control module returns to the second state. The wheel speed sensor current loop is turned on, and the wheel speed sensor resumes operation.

[0046] The wheel speed sensor power supply circuit provided by this invention can be directly adapted to a 48V power supply system. When the wheel speed sensor power supply line is connected to a power supply voltage of 48V or above, its power supply circuit can be automatically cut off. When the power supply voltage of 48V or above is removed from the wheel speed sensor, the wheel speed sensor can automatically restore its function. It is also compatible with the voltage withstand range of wheel speed sensors.

[0047] like Figure 1 As shown, in this embodiment, the loop control module includes a first transistor Q1, a first resistor R1, and a second resistor R2.

[0048] The collector of the first transistor Q1 is connected to the second terminal of the wheel speed sensor, and the emitter of the first transistor Q1 is grounded. Figure 1In the diagram, GND represents the ground wire. The base of the first transistor Q1 is connected to the first terminal of the first resistor R1, the second terminal of the first resistor R1 is connected to the first terminal of the second resistor R2, and the second terminal of the second resistor R2 is connected to the first GIO port GIO1 of the MCU. The first transistor Q1 is an NPN transistor.

[0049] The MCU's first GIO port, GIO1, can output a high or low level. When GIO1 outputs a high level, the first transistor Q1 is turned on, the loop control module is in the second state, and the wheel speed sensor current loop is on. When GIO1 outputs a low level, Q1 is turned off, the loop control module is in the first state, and the wheel speed sensor current loop is off.

[0050] The first resistor R1 and the second resistor R2 are current-limiting resistors used to limit the base current of the first transistor Q1 and prevent damage to the first transistor Q1.

[0051] like Figure 1 As shown, the overvoltage shutdown module includes a second transistor Q2, a third resistor R3, and a Zener diode Z1. The collector of the second transistor Q2 is connected to the first terminal of the second resistor R2, the emitter of the second transistor Q2 is grounded, the base of the second transistor Q2 is connected to the first terminal of the third resistor R3, and the second terminal of the third resistor R3 is connected to the first terminal of the wheel speed sensor via the Zener diode Z1. The second transistor Q2 is an NPN transistor.

[0052] When the voltage at the power supply terminal of the wheel speed sensor is within the normal range, the second transistor Q2 is in the off state, which does not affect the state of the loop control module. However, when an overvoltage occurs at the power supply terminal of the wheel speed sensor, the Zener diode Z1 conducts, causing the second transistor Q2 to conduct. Even if the MCU's first GIO port GIO1 still outputs a high level, the second transistor Q2 pulls down the base voltage of the first transistor Q1, thereby turning off the first transistor Q1 and allowing the loop control module to enter the first state, thus disconnecting the current loop of the wheel speed sensor.

[0053] The third resistor, R3, is a current-limiting resistor used to limit the base current of the second transistor Q2 and prevent damage to Q2.

[0054] like Figure 1As shown, the self-locking module includes a third transistor Q3, a fourth resistor R4, and a first diode D1. The emitter of the third transistor Q3 is connected to the power supply, the base of the third transistor Q3 is connected to the first terminal of the fourth resistor R4, the second terminal of the fourth resistor R4 is connected to the first terminal of the second resistor R2, the collector of the third transistor Q3 is connected to the anode of the first diode D1, and the cathode of the first diode D1 is connected to the second terminal of the third resistor R3. The third transistor Q3 is a PNP transistor.

[0055] When an overvoltage occurs at the power supply terminal of the wheel speed sensor, the second transistor Q2 turns on, pulling down the output voltage of the MCU's first GIO port GIO1. This causes the third transistor Q3 to turn on, continuously providing a conduction voltage to the second transistor Q2. Even if the voltage at the wheel speed sensor's power supply terminal returns to normal, under the action of the power supply VCC and the third transistor Q3, the second transistor Q2 remains in the on state. The second transistor Q2 will not turn off when the voltage at the wheel speed sensor's power supply terminal returns to normal, thus forming a self-locking mechanism.

[0056] The fourth resistor, R4, is a current-limiting resistor used to limit the base current of the third transistor Q3 and prevent damage to Q3.

[0057] like Figure 1 As shown, the unlocking module includes a fourth transistor Q4 and a fifth resistor R5. The first terminal of the fifth resistor R5 is connected to the second GIO port GIO2 of the MCU, and the second terminal of the fifth resistor R5 is connected to the base of the fourth transistor Q4. The emitter of the fourth transistor Q4 is grounded, and the collector of the fourth transistor Q4 is connected to the base of the second transistor Q2. The fourth transistor Q4 is an NPN transistor.

[0058] The MCU's second GIO port, GIO2, can output a high or low level. When the MCU's second GIO port, GIO2, outputs a high level, the fourth transistor, Q4, is turned on. When the MCU's second GIO port, GIO2, outputs a low level, the fourth transistor, Q4, is turned off.

[0059] In the latched state, when the fourth transistor Q4 is turned on, it will pull down the base voltage of the second transistor Q2, causing the second transistor Q2 to turn off, and the third transistor Q3 will also turn off, thus releasing the latch.

[0060] The fifth resistor, R5, is a current-limiting resistor used to limit the base current of the fourth transistor, Q4, to prevent damage to Q4.

[0061] The following describes the complete workflow of the wheel speed sensor power supply circuit of a 48V automotive power supply system according to the present invention.

[0062] In the initial state, the MCU's first GIO port GIO1 outputs a low level, and the MCU's second GIO port GIO2 also outputs a low level. The first transistor Q1 is off, and the fourth transistor Q4 is also off. At this time, the wheel speed sensor is not working. At the same time, the second transistor Q2 and the third transistor Q3 are also in the off state.

[0063] When the MCU's first GIO port GIO1 outputs a high level, the first transistor Q1 turns on, the loop control module enters the second state, the wheel speed sensor current loop is turned on, and the wheel speed sensor operates normally. The MCU acquires the wheel speed sensor signal and status signal through the GTM port. When the wheel speed sensor is operating normally, the MCU's second GIO port GIO2 still outputs a low level, and the fourth transistor Q4 is turned off. At the same time, the second transistor Q2 and the third transistor Q3 are also in the off state.

[0064] When an overvoltage occurs at the power supply terminal of the wheel speed sensor, the Zener diode Z1 conducts, causing the second transistor Q2 to conduct. The second transistor Q2 pulls down the output voltage of the MCU's first GIO port GIO1, causing the first transistor Q1 to turn off. The loop control module enters the first state, the wheel speed sensor current loop is disconnected, and it stops working. Simultaneously, the third transistor Q3 turns on and continuously provides conduction voltage to the second transistor Q2, forming a latching effect. At this time, the MCU's second GIO port GIO2 continues to output a low level, and the fourth transistor Q4 is turned off.

[0065] When the MCU detects that the voltage at the power supply terminal of the wheel speed sensor has returned to normal via the voltage detection module, the MCU's second GIO port GIO2 outputs a high level, and the fourth transistor Q4 turns on. The fourth transistor Q4 pulls down the base voltage of the second transistor Q2, causing Q2 to turn off. Q2 then no longer pulls down the output voltage of the MCU's first GIO port GIO1, causing the first transistor Q1 to turn on. The loop control module enters the second state, the wheel speed sensor current loop is activated, and the wheel speed sensor resumes normal operation. Simultaneously, the third transistor Q3 turns off, releasing the latch.

[0066] This invention implements overvoltage protection at the power supply terminal of the wheel speed sensor using a purely hardware-based approach, requiring no MCU intervention and offering a fast response time. Self-locking ensures that the wheel speed sensor current loop remains open after the fault voltage disappears, preventing repeated actions that could damage the sensor. The recovery process is actively controlled by the MCU, using a voltage detection module to continuously monitor the voltage at the wheel speed sensor's power supply terminal, ensuring safe recovery.

[0067] This embodiment describes an electronic device, including a wheel speed sensor power supply circuit for a 48V automotive power supply system as described in any embodiment of the present invention.

[0068] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention.

[0069] Those skilled in the art will recognize that the modules and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0070] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described apparatus and equipment can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0071] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0072] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0073] In addition, the functional modules in the embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0074] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0075] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

[0076] It should be understood that the sequence numbers of the steps in the invention's content and embodiments do not absolutely imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention. The foregoing description of embodiments of this disclosure has been provided for illustrative and descriptive purposes. The foregoing description is not exhaustive and is not intended to limit this disclosure to the exact form disclosed. Various modifications and variations may exist based on the foregoing teachings, or various modifications and variations may be derived from the practice of this disclosure. These embodiments were chosen and described to illustrate the principles of this disclosure and its practical application, so that those skilled in the art can utilize this disclosure in various implementations and modifications suitable for the specific purpose of the concept.

Claims

1. A wheel speed sensor power supply circuit for a 48V automotive electrical power supply system, characterized by Includes voltage detection module, dedicated chip, loop control module, self-locking module, overvoltage shutdown module, unlocking module, and MCU module; The voltage detection module is connected to the first end of the wheel speed sensor and the MCU module respectively. The first end of the wheel speed sensor is the power supply end of the wheel speed sensor. The voltage detection module is used to detect the voltage of the power supply end of the wheel speed sensor and feed the voltage of the power supply end of the wheel speed sensor back to the MCU module. The dedicated chip is connected to the first end of the wheel speed sensor and the MCU module respectively, and the dedicated chip is used to power the wheel speed sensor. The loop control module is connected to the second terminal of the wheel speed sensor and the MCU module respectively, and is used to control the on / off state of the wheel speed sensor current loop; when the loop control module is in the first state, the wheel speed sensor current loop is disconnected; when the loop control module is in the second state, the wheel speed sensor current loop is turned on. The overvoltage shutdown module is connected to the first terminal of the wheel speed sensor and the loop control module respectively. The overvoltage shutdown module is used to control the loop control module to enter the first state when the voltage at the power supply terminal of the wheel speed sensor exceeds the voltage threshold. The self-locking module is connected to the overvoltage shutdown module and the loop control module respectively. The self-locking module is used to realize the self-locking control of the overvoltage shutdown module when the voltage at the power supply terminal of the wheel speed sensor exceeds the voltage threshold, so that the loop control module is maintained in the first state. The unlocking module is connected to the MCU module and the overvoltage shutdown module respectively. The MCU module is used to release the self-locking of the overvoltage shutdown module through the unlocking module after the voltage at the power supply terminal of the wheel speed sensor returns to normal, so that the loop control module returns to the second state. The loop control module includes a first transistor, a first resistor, and a second resistor; The collector of the first transistor is connected to the second terminal of the wheel speed sensor, the emitter of the first transistor is grounded, the base of the first transistor is connected to the first terminal of the first resistor, the second terminal of the first resistor is connected to the first terminal of the second resistor, and the second terminal of the second resistor is connected to the first GIO port of the MCU. The overvoltage shutdown module includes a second transistor, a third resistor, and a Zener diode; The collector of the second transistor is connected to the first end of the second resistor, the emitter of the second transistor is grounded, the base of the second transistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the first end of the wheel speed sensor via the Zener diode.

2. The wheel speed sensor power supply circuit of the 48V power supply system of an automobile according to claim 1, wherein The first transistor is an NPN transistor.

3. The wheel speed sensor power supply circuit of a 48V automotive power supply system according to claim 1, characterized in that, The second transistor is an NPN transistor.

4. The wheel speed sensor power supply circuit of a 48V automotive power supply system according to claim 1, characterized in that, The self-locking module includes a third transistor, a fourth resistor, and a first diode; The emitter of the third transistor is connected to the power supply, the base of the third transistor is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the first end of the second resistor, the collector of the third transistor is connected to the anode of the first diode, and the cathode of the first diode is connected to the second end of the third resistor.

5. The wheel speed sensor power supply circuit of a 48V automotive power supply system according to claim 4, characterized in that, The third transistor is a PNP transistor.

6. The wheel speed sensor power supply circuit of a 48V automotive power supply system according to claim 1, characterized in that, The unlocking module includes a fourth transistor and a fifth resistor; The first end of the fifth resistor is connected to the second GIO port of the MCU, the second end of the fifth resistor is connected to the base of the fourth transistor, the emitter of the fourth transistor is grounded, and the collector of the fourth transistor is connected to the base of the second transistor.

7. The wheel speed sensor power supply circuit of a 48V automotive power supply system according to claim 6, characterized in that, The fourth transistor is an NPN transistor.

8. An electronic device, characterized in that, The invention includes a wheel speed sensor power supply circuit for a 48V automotive power supply system as described in any one of claims 1-7.

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