Automobile sensor acquisition system, SPC signal acquisition circuit and overcurrent protection circuit thereof

Abstract

The utility model provides an automobile sensor acquisition system, an SPC signal acquisition circuit and an over-current protection circuit thereof, the over-current protection circuit can be applied to the SPC signal acquisition circuit, and a first end of a voltage sampling unit and a first end of an over-current protection unit in the circuit are both connected to an emitter of a triode in the SPC signal acquisition circuit. The second end of the voltage sampling unit and the second end of the overcurrent protection unit are both grounded. A third end of the overcurrent protection unit is connected to a base electrode of the triode, and a fourth end of the overcurrent protection unit is used as a driving signal input end of the SPC signal acquisition circuit; when a short power supply phenomenon occurs in the SPC signal acquisition circuit, the first end of the voltage sampling unit outputs an overcurrent voltage to the base electrode of an overcurrent protection triode in the overcurrent protection unit, and the overcurrent protection triode is conducted, so that the problem that when a short power supply phenomenon occurs in a sensor in the existing SPC signal acquisition circuit, a triode driven by a timer is directly short-circuited to the ground, and the short power supply phenomenon is caused is solved. And the triode is burnt out.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to an automobile sensor acquisition system, an SPC signal acquisition circuit and an overcurrent protection circuit thereof. Background Art

[0002] As a new type of technical interface, SENT (Single Edge Nibble Transmission) sensors are widely used in automotive systems. They are mainly used in braking, steering, transmission and other systems to effectively improve the performance and safety of the car. The SENT protocol is unidirectional and can only be transmitted from the sensor to the controller.

[0003] The SPC protocol (ShortPWM Code) is an enhanced version based on the SENT protocol. It uses a single-line half-duplex method to transmit data, adds the MCU to send a trigger pulse, and realizes the ID selection function by changing the length of the trigger pulse. It can control up to 4 sensors.

[0004] In the automotive sensor acquisition system, the controller without SPC needs a timer to drive the transistor to realize the trigger function and add a SENT interface to realize SPC communication, that is, the trigger is realized through the SPC signal acquisition circuit. However, if the sensor has a short power supply phenomenon, the timer-driven transistor that realizes the trigger in the SPC signal acquisition circuit will be directly shorted to the ground, causing the transistor to burn out. Utility Model Content

[0005] In this regard, the present application provides an automobile sensor acquisition system, an SPC signal acquisition circuit and an overcurrent protection circuit thereof to solve the problem that in the existing SPC signal acquisition circuit, when a short power phenomenon occurs in the sensor, the timer-driven transistor will be directly short-circuited to the ground, causing the transistor to burn out.

[0006] To achieve the above objectives, the present application provides the following technical solutions:

[0007] In a first aspect, the present application discloses an overcurrent protection circuit, which is applied to an SPC signal acquisition circuit. The overcurrent protection circuit comprises: a voltage sampling unit and an overcurrent protection unit;

[0008] The first end of the voltage sampling unit and the first end of the overcurrent protection unit are both connected to the emitter of the transistor in the SPC signal acquisition circuit, and the second end of the voltage sampling unit and the second end of the overcurrent protection unit are both grounded;

[0009] The third end of the overcurrent protection unit is connected to the base of the transistor, and the fourth end of the overcurrent protection unit serves as a driving signal input end of the SPC signal acquisition circuit;

[0010] Among them, when a short power phenomenon occurs in the SPC signal acquisition circuit, the first end of the voltage sampling unit outputs a sampling voltage to the base of the overcurrent protection transistor in the overcurrent protection unit, and when the sampling voltage is greater than the turn-on voltage of the overcurrent protection transistor, the overcurrent protection transistor is turned on.

[0011] Optionally, in the above-mentioned overcurrent protection circuit, the voltage sampling unit includes: a sampling resistor, one end of the sampling resistor serves as the first end of the voltage sampling unit, and the other end of the sampling resistor serves as the second end of the voltage sampling unit.

[0012] Optionally, in the above-mentioned overcurrent protection circuit, the overcurrent protection unit includes: a base resistor, a pull-down resistor and the overcurrent protection transistor;

[0013] The base of the overcurrent protection transistor serves as the first end of the overcurrent protection unit; the collector of the overcurrent protection transistor is respectively connected to one end of the base resistor and one end of the pull-down resistor, the connection point serves as the third end of the overcurrent protection unit, and the other end of the base resistor serves as the fourth end of the overcurrent protection unit;

[0014] The emitter of the overcurrent protection transistor is connected to the other end of the pull-down resistor, and the connection point serves as the second end of the overcurrent protection unit.

[0015] The second aspect of the present application discloses an SPC signal acquisition circuit, comprising: a pull-up resistor, a transistor, and any overcurrent protection circuit disclosed in the first aspect;

[0016] Among them, one end of the pull-up resistor receives the pull-up voltage; the other end of the pull-up resistor is connected to the collector of the transistor, and the connection point serves as the signal transmission end of the SPC signal acquisition circuit, which is respectively connected to the sensor interface of the sensor and the controller;

[0017] The base of the transistor serves as a driving signal input terminal of the SPC signal acquisition circuit and is connected to a sensor signal transmission trigger interface of the controller.

[0018] Optionally, the above-mentioned SPC signal acquisition circuit further includes: a surge protection unit, a first end of the surge protection unit is connected to the signal transmission end of the SPC signal acquisition circuit, and a second end of the surge protection unit is grounded.

[0019] Optionally, in the above-mentioned SPC signal acquisition circuit, the surge protection unit includes: a transient suppression diode, one end of the transient suppression diode serves as the first end of the surge protection unit, and the other end of the transient suppression diode serves as the second end of the surge protection unit.

[0020] Optionally, the above-mentioned SPC signal acquisition circuit further includes: a filtering unit, a first end of the filtering unit is connected to the signal transmission end of the SPC signal acquisition circuit, and a second end of the filtering unit is connected to the sensor interface of the controller.

[0021] Optionally, in the above-mentioned SPC signal acquisition circuit, the filtering unit includes: a filtering bead, a filtering resistor and a filtering capacitor;

[0022] Wherein, one end of the filter magnetic bead serves as the first end of the filter unit, and the other end of the filter magnetic bead is connected to one end of the filter resistor;

[0023] The other end of the filter resistor is connected to one end of the filter capacitor, and the connection point serves as the first end of the filter unit;

[0024] The other end of the filter capacitor is grounded.

[0025] The third aspect of the present application discloses an automobile sensor acquisition system, comprising: a sensor, a controller, and an SPC signal acquisition circuit as described in any one of the items disclosed in the second aspect;

[0026] Among them, the sensor is connected to the controller through the SPC signal acquisition circuit, and the controller is provided with a SENT interface and an IO interface. The SENT interface serves as the sensor interface of the controller, and the IO interface serves as the sensor signal transmission trigger interface of the controller.

[0027] Optionally, in the above-mentioned automobile sensor acquisition system, the sensor is a SENT sensor, or a SPC sensor.

[0028] The overcurrent protection circuit provided in the present application can be applied to an SPC signal acquisition circuit, and the circuit includes: a voltage sampling unit and an overcurrent protection unit; the first end of the voltage sampling unit and the first end of the overcurrent protection unit are both connected to the emitter of a transistor in the SPC signal acquisition circuit, and the second end of the voltage sampling unit and the second end of the overcurrent protection unit are both grounded; the third end of the overcurrent protection unit is connected to the base of the transistor, and the fourth end of the overcurrent protection unit serves as a drive signal input end of the SPC signal acquisition circuit; wherein, when a short power supply phenomenon occurs in the SPC signal acquisition circuit, the first end of the voltage sampling unit outputs an overcurrent voltage to the base of the overcurrent protection transistor in the overcurrent protection unit, and the overcurrent protection transistor is turned on, thereby solving the problem that when a short power supply phenomenon occurs in the sensor of the existing SPC signal acquisition circuit, the transistor driven by the timer will be directly short-connected to the ground, causing the transistor to burn out. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0030] Figure 1 A circuit diagram of an existing SPC signal acquisition circuit applied to an automobile sensor acquisition system provided in an embodiment of the present application;

[0031] Figure 2 A schematic diagram of an overcurrent protection circuit applied to an SPC signal acquisition circuit provided in an embodiment of the present application;

[0032] Figure 3 A circuit diagram of an SPC signal acquisition circuit applied to an automobile sensor acquisition system provided in an embodiment of the present application;

[0033] Figure 4 A circuit diagram of another SPC signal acquisition circuit applied to an automobile sensor acquisition system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] First of all, the connection between the SPC signal acquisition circuit and the sensor and controller in the current automotive sensor acquisition system is as follows: Figure 1 As shown, the SPC signal acquisition circuit mainly includes a pull-up resistor R1 and a transistor Q1. When a short power phenomenon occurs in the sensor, the transistor Q1 driven by the timer will be directly short-connected to the ground, causing the transistor Q1 to burn out.

[0036] Based on this, an embodiment of the present application provides an overcurrent protection circuit to solve the problem that when a short power phenomenon occurs in the sensor of the existing SPC signal acquisition circuit, the transistor Q1 driven by the timer will be directly short-circuited to the ground, causing the transistor Q1 to burn out.

[0037] See also Figure 2 The overcurrent protection circuit can be applied to an SPC signal acquisition circuit, and mainly includes: a voltage sampling unit 101 and an overcurrent protection unit 102 .

[0038] The first end of the voltage sampling unit 101 and the first end of the overcurrent protection unit 102 are both connected to the emitter of the transistor Q1 in the SPC signal acquisition circuit, and the second end of the voltage sampling unit 101 and the second end of the overcurrent protection unit 102 are both grounded; the third end of the overcurrent protection unit 102 is connected to the base of the transistor Q1, and the fourth end of the overcurrent protection unit 102 serves as the drive signal input end of the SPC signal acquisition circuit;

[0039] Among them, when a short power phenomenon occurs in the SPC signal acquisition circuit, the first end of the voltage sampling unit 101 outputs an overcurrent voltage to the base of the overcurrent protection transistor Q2 in the overcurrent protection unit 102. When the sampling voltage is greater than the turn-on voltage of the overcurrent protection transistor Q2, the overcurrent protection transistor Q2 is turned on.

[0040] In practical applications, the drive signal input end of the SPC signal acquisition circuit is generally connected to the sensor signal transmission trigger interface of the controller to receive the sensor signal transmission trigger signal sent by the controller.

[0041] In some embodiments, Figure 2 As shown, the voltage sampling unit 101 may include: a sampling resistor R2 , one end of the sampling resistor R2 serving as a first end of the voltage sampling unit 101 , and the other end of the sampling resistor R2 serving as a second end of the voltage sampling unit 101 .

[0042] Among them, the resistance value of the sampling resistor R2 can be 100Ω, of course, it is not limited to this, and can also be determined according to the application environment and user needs. This application does not limit it and it is within the protection scope of this application.

[0043] In some embodiments, Figure 2 As shown, the overcurrent protection unit 102 may include: a base resistor R4, a pull-down resistor R3 and an overcurrent protection transistor Q2.

[0044] Among them, the base of the overcurrent protection transistor Q2 serves as the first end of the overcurrent protection unit 102; the collector of the overcurrent protection transistor Q2 is respectively connected to one end of the base resistor R4 and one end of the pull-down resistor R3, and the connection point serves as the third end of the overcurrent protection unit 102, and the other end of the base resistor R4 serves as the fourth end of the overcurrent protection unit 102; the emitter of the overcurrent protection transistor Q2 is connected to the other end of the pull-down resistor R3, and the connection point serves as the second end of the overcurrent protection unit 102.

[0045] Specifically, the resistance of the base resistor R4 can be 10kΩ, and the resistance of the pull-down resistor R3 can be 300kΩ; of course, it is not limited to this, and can also be determined according to the application environment and user needs. This application does not limit it and it is within the protection scope of this application.

[0046] In practical applications, since the collector of the transistor Q1 in the SPC signal acquisition circuit is connected to the sensor, it can be specifically connected to the signal output end of the sensor. When the signal output end of the sensor is short-connected to the battery, the collector voltage of the transistor Q1 is the battery voltage, and a large current flows through the sampling resistor R2. When the sampling voltage of the sampling resistor R2 is greater than the turn-on voltage of the overcurrent protection transistor Q2 in the overcurrent protection unit 102, the overcurrent protection transistor Q2 is turned on, and the base of the transistor Q1 in the SPC signal acquisition circuit is short-circuited to the ground, so that the transistor Q1 in the SPC signal acquisition circuit is turned off, thereby ensuring that the transistor Q1 in the SPC signal acquisition circuit is not damaged by the short-circuited power supply.

[0047] For example, when the battery voltage is 12V, the turn-on voltage of the overcurrent protection transistor Q2 in the overcurrent protection unit 102 can be 0.7V; of course, it is not limited to this. The turn-on voltage of the overcurrent protection transistor Q2 can also be determined according to the specific application and user needs. This application does not make specific limitations and is within the protection scope of this application.

[0048] Based on the above principle, the overcurrent protection circuit provided in this embodiment can be applied to the SPC signal acquisition circuit, which includes: a voltage sampling unit 101 and an overcurrent protection unit 102; the first end of the voltage sampling unit 101 and the first end of the overcurrent protection unit 102 are both connected to the emitter of the transistor Q1 in the SPC signal acquisition circuit, and the second end of the voltage sampling unit 101 and the second end of the overcurrent protection unit 102 are both grounded; the third end of the overcurrent protection unit 102 is connected to the base of the transistor Q1, and the fourth end of the overcurrent protection unit 102 serves as the driving signal input end of the SPC signal acquisition circuit; wherein, when a short power phenomenon occurs in the SPC signal acquisition circuit, the first end of the voltage sampling unit 101 outputs an overcurrent voltage to the base of the overcurrent protection transistor Q2 in the overcurrent protection unit 102, and the overcurrent protection transistor Q2 is turned on, thereby solving the problem that when a short power phenomenon occurs in the sensor of the existing SPC signal acquisition circuit, the transistor Q1 driven by the timer will be directly shorted to the ground, causing the transistor Q1 to burn out.

[0049] Optionally, based on the overcurrent protection circuit provided in the above embodiment, another embodiment of the present application further provides an SPC signal acquisition circuit, see Figure 2 , the SPC signal acquisition circuit may include: a pull-up resistor R1, a transistor Q1 and an overcurrent protection circuit as described in any of the above embodiments;

[0050] Among them, one end of the pull-up resistor R1 receives the pull-up voltage; the other end of the pull-up resistor R1 is connected to the collector of the transistor Q1, and the connection point serves as the signal transmission end of the SPC signal acquisition circuit, and is respectively connected to the sensor interface (SENT in the figure) of the sensor and the controller;

[0051] The base of transistor Q1 is used as the driving signal input terminal of the SPC signal acquisition circuit and is connected to the sensor signal transmission trigger interface (IO in the figure) of the controller.

[0052] In actual applications, when the sensor type is an SPC sensor, an external pull-up resistor R1 is required. R1 in the figure is the pull-up resistor R1; specifically, the resistance value of the pull-up resistor R1 can be 51KΩ; of course, it is not limited to this, and can also be determined according to the application environment and user needs. This application does not limit it and it is within the protection scope of this application.

[0053] In actual applications, one end of the pull-up resistor R1 is connected to the pull-up voltage. The main purpose is to provide a pull-up voltage for the SPC signal acquisition circuit. The specific voltage value of the pull-up voltage can be determined according to the application environment and user needs. This application does not make specific limitations and is within the protection scope of this application. The figure only takes a 5V pull-up voltage as an example.

[0054] Assuming that the resistance of the sampling resistor R2 is 100Ω, the resistance of the base resistor R4 is 10kΩ, the resistance of the pull-down resistor R3 is 300kΩ, and the resistance of the pull-up resistor R1 is 51KΩ, the trigger signal output by the sensor signal transmission trigger interface of the controller can be a high level 3.3V or a low level 0V.

[0055] When the trigger signal is at a low level of 0V, the base of transistor Q1 in the SPC signal acquisition circuit is 0V, transistor Q1 is not turned on, the sensor recognizes a high level, and the sensor does not transmit a signal.

[0056] When the trigger signal is at a high level of 3.3V, the voltage divided by the base resistor R4 and the pull-down resistor R3 is 3V, which is greater than the turn-on voltage of the transistor Q1, ensuring that the transistor Q1 is in the on state. At this time, the emitter of the transistor Q1 is connected to the ground through the sampling resistor R2, and the voltage divided by the pull-up resistor R1 and the pull-down resistor R3 is close to 0V. The sensor recognizes the low-level trigger signal and starts to parse the SPC protocol.

[0057] Based on the above principle, the SPC signal acquisition circuit provided in this invention can protect the transistor Q1 in the SPC signal acquisition circuit by setting an overcurrent protection circuit, thereby solving the problem that when a short power phenomenon occurs in the sensor in the existing SPC signal acquisition circuit, the transistor Q1 driven by the timer will be directly short-connected to the ground, causing the transistor Q1 to burn out.

[0058] It should be noted that the relevant description about the overcurrent protection circuit can be found in the above corresponding embodiments, which will not be repeated here.

[0059] Optionally, based on the SPC signal acquisition circuit provided in the above embodiment, as Figure 3As shown, the SPC signal acquisition circuit provided in another embodiment of the present application may also include: a surge protection unit 201, a first end of the surge protection unit 201 is connected to the signal transmission end of the SPC signal acquisition circuit, and a second end of the surge protection unit 201 is grounded.

[0060] With reference to the drawings, specifically, the first end of the surge protection unit 201 may be connected to a signal output end of the sensor.

[0061] like Figure 3 As shown, the surge protection unit 201 may include: a transient suppression diode D1 , one end of the transient suppression diode D1 serving as a first end of the surge protection unit 201 , and the other end of the transient suppression diode D1 serving as a second end of the surge protection unit 201 .

[0062] Of course, this is not limited to this. Other existing switch tubes with surge protection function can also be used in the surge protection unit 201. This application does not make specific limitations on them, and they are all within the protection scope of this application.

[0063] In practical applications, adding a transient suppression diode D1 in the SPC signal acquisition circuit can play the role of ESD (Electro-Static discharge) protection.

[0064] Optionally, based on the SPC signal acquisition circuit provided in the above embodiment, as Figure 4 As shown, the SPC signal acquisition circuit provided in another embodiment of the present application may also include: a filtering unit 202, a first end of the filtering unit 202 is connected to the signal transmission end of the SPC signal acquisition circuit, and a second end of the filtering unit 202 is connected to the sensor interface of the controller.

[0065] like Figure 4 As shown, the filter unit 202 may include: a filter bead L1, a filter resistor R5 and a filter capacitor C1;

[0066] Among them, one end of the filter bead L1 serves as the first end of the filter unit 202, and the other end of the filter bead L1 is connected to one end of the filter resistor R5; the other end of the filter resistor R5 is connected to one end of the filter capacitor C1, and the connection point serves as the first end of the filter unit 202; the other end of the filter capacitor C1 is grounded.

[0067] In practical applications, the filter bead L1 can play a filtering role when the signal is infected; the filter resistor R5 and the filter capacitor C1 form an RC filter circuit, which can also play the role of a filter circuit.

[0068] It should be noted that for the relevant description of the SPC signal acquisition circuit, reference can be made to the existing related technologies, and this application will not go into details.

[0069] In practical applications, existing automotive sensor acquisition systems often use a timer plus a SENT interface to implement SPC communication. However, this method requires occupying one timer output of the controller.

[0070] In this regard, optionally, another embodiment of the present application further provides an automobile sensor acquisition system, see Figure 4 , the automobile sensor acquisition system mainly includes: a sensor, a controller and an SPC signal acquisition circuit as described in any of the above embodiments;

[0071] Among them, the sensor is connected to the controller through the SPC signal acquisition circuit. The controller is equipped with a SENT interface (SENT in the figure) and an IO interface (IO in the figure). The SENT interface serves as the sensor interface of the controller, and the IO interface serves as the sensor signal transmission trigger interface of the controller.

[0072] It should be noted that by replacing the timer with an IO interface, controller resources can be saved, solving the problem that the existing automotive sensor acquisition system commonly uses a timer plus a SENT interface to implement SPC communication, which will occupy one timer output of the controller.

[0073] In some embodiments, the specific type of the sensor may be a SENT sensor, that is, the sensor is a sensor that uses the SENT protocol for data transmission, or an SPC sensor, that is, the sensor is a sensor that uses the SPC protocol for control; of course, it is not limited to this, and it may also be other existing sensors, which are not limited in this application and are all within the scope of protection of this application.

[0074] In practical applications, the controller can use FOR loop processing to process the output signal of the sensor signal transmission trigger interface, first output the IO interface to 3.3V, delay for a period of time, output 0V, and then delay for a period of time, continuously cycle, and generate a sensor transmission trigger signal for the SPC signal acquisition circuit to trigger the sensor to transmit the signal.

[0075] Specifically, the length of the delay time, which represents the duration of the low level of the trigger signal, as a trigger selection function in the SPC protocol, can be adjusted in combination with the actual application environment and user needs.

[0076] In actual applications, if the terminal sensor of the automotive sensor acquisition system only supports the SENT protocol, the controller can disable the IO interface and only use the SENT interface to parse the signal, thereby achieving compatible design of the SENT and SPC protocols.

[0077] It should be noted that, for the relevant description of the SPC signal acquisition circuit, reference may be made to the above-mentioned corresponding embodiments, and for the relevant description of the automobile sensor acquisition system, reference may be made to the prior art, which will not be described in detail in this application.

[0078] The features recorded in the various embodiments in this specification can be replaced or combined with each other, and the same and similar parts between the various embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative work.

[0079] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0080] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

[0081] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

Claims

1. An overcurrent protection circuit, characterized in that: Applied to the SPC signal acquisition circuit, the overcurrent protection circuit comprises: a voltage sampling unit and an overcurrent protection unit; The first end of the voltage sampling unit and the first end of the overcurrent protection unit are both connected to the emitter of the transistor in the SPC signal acquisition circuit, and the second end of the voltage sampling unit and the second end of the overcurrent protection unit are both grounded; The third end of the overcurrent protection unit is connected to the base of the transistor, and the fourth end of the overcurrent protection unit serves as a driving signal input end of the SPC signal acquisition circuit; Among them, when a short power phenomenon occurs in the SPC signal acquisition circuit, the first end of the voltage sampling unit outputs a sampling voltage to the base of the overcurrent protection transistor in the overcurrent protection unit, and when the sampling voltage is greater than the turn-on voltage of the overcurrent protection transistor, the overcurrent protection transistor is turned on.

2. The overcurrent protection circuit according to claim 1, characterized in that: The voltage sampling unit includes: a sampling resistor, one end of the sampling resistor serves as a first end of the voltage sampling unit, and the other end of the sampling resistor serves as a second end of the voltage sampling unit.

3. The overcurrent protection circuit according to claim 1, characterized in that: The overcurrent protection unit comprises: a base resistor, a pull-down resistor and the overcurrent protection transistor; The base of the overcurrent protection transistor serves as the first end of the overcurrent protection unit; the collector of the overcurrent protection transistor is respectively connected to one end of the base resistor and one end of the pull-down resistor, the connection point serves as the third end of the overcurrent protection unit, and the other end of the base resistor serves as the fourth end of the overcurrent protection unit; The emitter of the overcurrent protection transistor is connected to the other end of the pull-down resistor, and the connection point serves as the second end of the overcurrent protection unit.

4. An SPC signal acquisition circuit, characterized in that: include: A pull-up resistor, a transistor, and an overcurrent protection circuit as claimed in any one of claims 1 to 3; Among them, one end of the pull-up resistor receives the pull-up voltage; the other end of the pull-up resistor is connected to the collector of the transistor, and the connection point serves as the signal transmission end of the SPC signal acquisition circuit, which is respectively connected to the sensor interface of the sensor and the controller; The base of the transistor serves as a driving signal input terminal of the SPC signal acquisition circuit and is connected to a sensor signal transmission trigger interface of the controller.

5. The SPC signal acquisition circuit according to claim 4, characterized in that: Also includes: A surge protection unit, wherein a first end of the surge protection unit is connected to a signal transmission end of the SPC signal acquisition circuit, and a second end of the surge protection unit is grounded.

6. The SPC signal acquisition circuit according to claim 5, characterized in that: The surge protection unit includes: a transient suppression diode, one end of the transient suppression diode serves as a first end of the surge protection unit, and the other end of the transient suppression diode serves as a second end of the surge protection unit.

7. The SPC signal acquisition circuit according to claim 4, characterized in that: Also includes: A filtering unit, wherein a first end of the filtering unit is connected to a signal transmission end of the SPC signal acquisition circuit, and a second end of the filtering unit is connected to a sensor interface of the controller.

8. The SPC signal acquisition circuit according to claim 7, characterized in that: The filtering unit comprises: filtering beads, filtering resistors and filtering capacitors; Wherein, one end of the filter magnetic bead serves as the first end of the filter unit, and the other end of the filter magnetic bead is connected to one end of the filter resistor; The other end of the filter resistor is connected to one end of the filter capacitor, and the connection point serves as the first end of the filter unit; The other end of the filter capacitor is grounded.

9. An automobile sensor acquisition system, characterized in that: include: A sensor, a controller, and an SPC signal acquisition circuit as described in any one of claims 4 to 8; Among them, the sensor is connected to the controller through the SPC signal acquisition circuit, and the controller is provided with a SENT interface and an IO interface. The SENT interface serves as the sensor interface of the controller, and the IO interface serves as the sensor signal transmission trigger interface of the controller.

10. The automobile sensor acquisition system according to claim 9, characterized in that: The sensor is a SENT sensor or a SPC sensor.

Images