Vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit

Abstract

The utility model relates to a vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit, which belongs to the technical field of charging piles and comprises a step-down isolation circuit, a differential amplification circuit, a signal conditioning circuit, a first filtering and port protection circuit, a second filtering and port protection circuit and a processor. The output end of the voltage reduction isolation circuit is connected with the input end of the differential amplification circuit, the output end of the differential amplification circuit is connected with the input end of the first filtering and port protection circuit, and the output end of the first filtering and port protection circuit is connected with the input end of the processor. The output end of the differential amplification circuit is further connected with the input end of the second filtering and port protection circuit, and the output end of the second filtering and port protection circuit is connected with the input end of the processor. According to the utility model, the technical problem of high cost of bus voltage acquisition and vehicle-mounted battery polarity detection in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of charging piles, and in particular to a vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit. Background Art

[0002] With the increasing popularity of electric vehicles and the development of the new energy industry, the market share of DC charging piles has increased dramatically. DC charging piles often use high voltage to charge electric vehicles. To ensure the safety of both the charging vehicle and the charging operator, it is essential to design a circuit that can accurately collect bus voltage. Furthermore, to prevent the polarity of the high-voltage DC output of the DC charging pile from being opposite to that of the onboard battery to be charged, potentially causing an explosion and safety accident, the DC charging pile must have a reverse polarity detection function for the onboard battery to prevent this potential hazard. The current mainstream implementation method separates bus voltage collection and onboard battery polarity detection into two separate circuits, which occupies more space on the PCB and increases costs. Therefore, the existing technology faces the technical problem of high costs for bus voltage collection and onboard battery polarity detection. Utility Model Content

[0003] In view of this, it is necessary to provide a vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit to solve the technical problem of high cost of bus voltage acquisition and vehicle-mounted battery polarity detection.

[0004] In order to achieve the above objectives, the utility model provides a vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit, comprising:

[0005] Buck isolation circuit, differential amplifier circuit, signal conditioning circuit, first filtering and port protection circuit, second filtering and port protection circuit and processor;

[0006] The output end of the step-down isolation circuit is connected to the input end of the differential amplifier circuit, the output end of the differential amplifier circuit is connected to the input end of the first filter and port protection circuit, and the output end of the first filter and port protection circuit is connected to the input end of the processor;

[0007] The output end of the differential amplifier circuit is also connected to the input end of the second filtering and port protection circuit, and the output end of the second filtering and port protection circuit is connected to the input end of the processor.

[0008] In a possible implementation, the processor includes: a bus voltage sampling port, where the bus voltage sampling port is connected to an output end of the first filtering and port protection circuit.

[0009] In a possible implementation, the processor further includes: an on-board battery reverse connection detection port, which is connected to the output end of the second filter and port protection circuit.

[0010] In a possible implementation, the step-down isolation circuit includes: an analog isolation chip, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a third capacitor;

[0011] Pin 1 of the isolation chip is connected to the second capacitor and the positive electrode of VDC at one point, the other end of the second capacitor is connected to the negative electrode of VDC, pin 4 of the isolation chip is connected to the negative electrode of VDC, pin 5 of the isolation chip is grounded, pin 6 of the isolation chip is connected to the negative electrode of VOUT, pin 7 of the isolation chip is connected to the positive electrode of VOUT, and pin 8 of the isolation chip is connected to the third capacitor and the positive electrode of VDC at one point;

[0012] Pins 3 and 4 of the isolation chip are connected to the two ends of the first capacitor respectively;

[0013] The second resistor, the third resistor and the fourth resistor are connected in series with the first capacitor;

[0014] The first resistor, the second resistor and the third resistor are connected to one point;

[0015] One end of the first resistor is connected to the positive electrode of VDC;

[0016] One end of the fourth resistor is connected to the negative electrode of VDC.

[0017] In a possible implementation, one end of the third capacitor is grounded.

[0018] In a possible implementation, the model of the analog isolation chip is: NSI1312D.

[0019] In a possible implementation, the differential amplifier circuit includes: a first operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, and an eighth capacitor;

[0020] The positive power supply terminal of the first operational amplifier is connected in series with the seventh capacitor and GND, the negative power supply terminal of the first operational amplifier is connected in series with the eighth capacitor and GND, the output terminal of the first operational amplifier is connected in series with the eighth resistor and the inverting input terminal of the first operational amplifier, and the non-inverting input terminal of the first operational amplifier is connected in series with the seventh resistor and the fifth capacitor;

[0021] One end of the fourth capacitor is connected to the fifth capacitor, and the other end of the fourth capacitor is connected to the sixth capacitor;

[0022] One end of the fifth resistor is connected to the positive electrode of VOUT, and the other end of the fifth resistor intersects the fifth capacitor and the fourth capacitor at a point;

[0023] One end of the sixth resistor is connected to the negative electrode of VOUT, and the other end of the sixth resistor intersects the fourth capacitor and the sixth capacitor at a point.

[0024] In a possible implementation, the signal conditioning circuit includes: a second operational amplifier, a ninth resistor, a tenth resistor, an eleventh resistor, a thirteenth resistor, and a fourteenth resistor;

[0025] An output terminal of the second operational amplifier is connected in series with a fourteenth resistor and a thirteenth resistor, a non-inverting input terminal of the second operational amplifier is connected to an eleventh resistor and is grounded, and an inverting input terminal of the second operational amplifier is connected in series with a ninth resistor and VOUT;

[0026] The inverting input terminal of the second operational amplifier and the output terminal of the second operational amplifier are connected via a tenth resistor.

[0027] In a possible implementation, the first filtering and port protection circuit includes: a twelfth resistor, a ninth capacitor, and a first clamping diode;

[0028] One end of the twelfth resistor is connected to VOUT, and the other end of the twelfth resistor is connected to the first clamping diode;

[0029] One end of the ninth capacitor intersects the twelfth resistor and the first clamping diode at a point, and the other end of the ninth capacitor is grounded;

[0030] One end of the clamping diode is connected to a power supply, and the other end of the first clamping diode is grounded.

[0031] In a possible implementation, the second filtering and port protection circuit includes: a tenth capacitor and a second clamping diode;

[0032] A tenth capacitor is connected to the second clamping diode;

[0033] One end of the tenth capacitor is connected to VOUT, and the other end of the tenth capacitor is grounded;

[0034] One end of the second clamping diode is connected to the power supply, and the other end of the second clamping diode is grounded.

[0035] The utility model provides a vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit, comprising: a step-down isolation circuit, a differential amplifier circuit, a signal conditioning circuit, a first filter and port protection circuit, a second filter and port protection circuit, and a processor; the output end of the step-down isolation circuit is connected to the input end of the differential amplifier circuit, the output end of the differential amplifier circuit is connected to the input end of the first filter and port protection circuit, the output end of the first filter and port protection circuit is connected to the input end of the processor; the output end of the differential amplifier circuit is also connected to the input end of the second filter and port protection circuit, the output end of the second filter and port protection circuit is connected to the input end of the processor. This application designs the on-board battery reverse connection detection and bus voltage acquisition circuit of the DC charging pile into the charging control board of the DC charging pile to solve the technical problem of high cost of bus voltage acquisition and on-board battery polarity detection, and performs bus voltage sampling by connecting the step-down isolation circuit, the first output end of the differential amplifier circuit, the first filter and port protection circuit and the processor in series in sequence; and performs on-board battery reverse connection detection by connecting the step-down isolation circuit, the second output end of the differential amplifier circuit, the signal conditioning circuit, the second filter and port protection circuit and the processor in series in sequence. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a system architecture diagram of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the utility model;

[0037] Figure 2 This is a step-down isolation circuit diagram of an embodiment of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the present utility model;

[0038] Figure 3 This is a differential amplifier circuit diagram of an embodiment of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the present utility model;

[0039] Figure 4 This is a signal conditioning circuit diagram of an embodiment of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the utility model;

[0040] Figure 5 This is a first filtering and port protection circuit diagram of an embodiment of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the utility model;

[0041] Figure 6 This is a second filtering and port protection circuit diagram of an embodiment of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the present utility model. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, and are not used to limit the scope of the present invention.

[0043] Figure 1 This is the system architecture diagram of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the utility model, including:

[0044] Buck isolation circuit, differential amplifier circuit, signal conditioning circuit, first filtering and port protection circuit, second filtering and port protection circuit and processor;

[0045] The step-down isolation circuit, the first output end of the differential amplifier circuit, the first filter and port protection circuit, and the processor are sequentially connected in series;

[0046] The second output end of the differential amplifier circuit, the signal conditioning circuit, the second filtering and port protection circuit, and the processor are sequentially connected in series.

[0047] It can be understood that the present invention provides a vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit, including: a step-down isolation circuit, a differential amplifier circuit, a signal conditioning circuit, a first filter and port protection circuit, a second filter and port protection circuit and a processor; the output end of the step-down isolation circuit is connected to the input end of the differential amplifier circuit, the output end of the differential amplifier circuit is connected to the input end of the first filter and port protection circuit, and the output end of the first filter and port protection circuit is connected to the input end of the processor; the output end of the differential amplifier circuit is also connected to the input end of the second filter and port protection circuit, and the output end of the second filter and port protection circuit is connected to the input end of the processor. This application designs the on-board battery reverse connection detection and bus voltage acquisition circuit of the DC charging pile into the charging control board of the DC charging pile to solve the technical problem of high cost of bus voltage acquisition and on-board battery polarity detection, and performs bus voltage sampling by connecting the step-down isolation circuit, the first output end of the differential amplifier circuit, the first filter and port protection circuit and the processor in series in sequence; and performs on-board battery reverse connection detection by connecting the step-down isolation circuit, the second output end of the differential amplifier circuit, the signal conditioning circuit, the second filter and port protection circuit and the processor in series in sequence.

[0048] In some embodiments of the present invention, the processor includes: a bus voltage sampling port, which is connected to the output end of the first filter and port protection circuit.

[0049] In some embodiments of the present invention, the processor further includes: an on-board battery reverse connection detection port, which is connected to the output end of the second filter and port protection circuit.

[0050] Figure 2 This is a step-down isolation circuit diagram of an embodiment of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the utility model, including: an analog isolation chip, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor and a third capacitor;

[0051] Pin 1 of the isolation chip is connected to the second capacitor and the positive electrode of VDC (Voltage Direct Current) at one point. The other end of the second capacitor is connected to the negative electrode of VDC. Pin 4 of the isolation chip is connected to the negative electrode of VDC. Pin 5 of the isolation chip is grounded. Pin 6 of the isolation chip is connected to the negative electrode of VOUT (the voltage output terminal after regulation). Pin 7 of the isolation chip is connected to the positive electrode of VOUT. Pin 8 of the isolation chip is connected to the third capacitor and the positive electrode of VDC at one point.

[0052] Pins 3 and 4 of the isolation chip are connected to the two ends of the first capacitor respectively;

[0053] The second resistor, the third resistor and the fourth resistor are connected in series with the first capacitor;

[0054] The first resistor, the second resistor and the third resistor are connected to one point;

[0055] One end of the first resistor is connected to the positive electrode of VDC;

[0056] One end of the fourth resistor is connected to the negative electrode of VDC.

[0057] It can be understood that the main function of the step-down isolation circuit is to step down the DC150V-DC1500V high voltage input of the charging bus, so that the voltage is converted into a low voltage input to the subsequent isolation circuit. The output of the isolation circuit can be directly collected by the processor after adjustment.

[0058] It can be further understood that if Figure 2 The step-down isolation circuit shown consists of a high-precision first resistor R1 (R1 is actually composed of multiple resistors connected in series, simplified as R1 in the drawing), a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a third capacitor C3, and an isolation chip U1. J1 is the bus voltage input interface. The high-precision first resistor R1 and the second resistor R2 form a resistor divider network. U1 is the analog isolation chip NSI1312D, with a maximum input voltage of ±1.2V and a 1:1 amplification ratio between the front-end input and the back-end output. The isolation effect can be achieved only when the isolation front and back ends are grounded separately. The front and back ends are both powered by +5V. The high-precision third resistor R3 and the fourth resistor R4 are matching resistors for the input of the analog isolation chip NSI1312D. C1, C2, and C3 are filter capacitors.

[0059] It can be further understood that the resistor divider network composed of R1 and R2 divides the bus input DC150V-DC1500V high voltage. In this circuit, preferably, R1 takes a value of 3297.8KΩ and R2 takes a value of 2.2KΩ. The resistance value can be adjusted according to the actual usage scenario.

[0060] In some embodiments of the present invention, one end of the third capacitor is grounded.

[0061] In some embodiments of the present invention, the model of the analog isolation chip is: NSI1312D.

[0062] Figure 3 This is a differential amplifier circuit diagram of an embodiment of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the utility model, including: a first operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, and an eighth capacitor;

[0063] The positive power supply terminal of the first operational amplifier is connected in series with the seventh capacitor and GND, the negative power supply terminal of the first operational amplifier is connected in series with the eighth capacitor and GND, the output terminal of the first operational amplifier is connected in series with the eighth resistor and the inverting input terminal of the first operational amplifier, and the non-inverting input terminal of the first operational amplifier is connected in series with the seventh resistor and the fifth capacitor;

[0064] One end of the fourth capacitor is connected to the fifth capacitor, and the other end of the fourth capacitor is connected to the sixth capacitor;

[0065] One end of the fifth resistor is connected to the positive electrode of VOUT, and the other end of the fifth resistor intersects the fifth capacitor and the fourth capacitor at a point;

[0066] One end of the sixth resistor is connected to the negative electrode of VOUT, and the other end of the sixth resistor intersects the fourth capacitor and the sixth capacitor at a point.

[0067] It can be understood that the differential amplifier circuit mainly amplifies the isolated voltage signal output by the analog isolation chip, so that the resolution of the measured signal becomes higher and the measurement accuracy is more accurate. Figure 3 The differential amplifier circuit shown is composed of a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, and an operational amplifier U2A, where U2A is a rail-to-rail operational amplifier SGM8270, powered by a dual power supply of ±5V; U2A and resistors R5, R6, R7, and R8 form a differential amplifier; capacitors C4, C5, C6, C7, and C8 are all filter capacitors.

[0068] It should be further understood that in this circuit, preferably, resistors R5 = R6 = 10K; resistors R7 = R8 = 30K, and the resistance values can be adjusted according to the actual usage scenario.

[0069] Figure 4 This is a signal conditioning circuit diagram of an embodiment of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the present invention, comprising: a second operational amplifier, a ninth resistor, a tenth resistor, an eleventh resistor, a thirteenth resistor, and a fourteenth resistor;

[0070] An output terminal of the second operational amplifier is connected in series with a fourteenth resistor and a thirteenth resistor, a non-inverting input terminal of the second operational amplifier is connected to an eleventh resistor and is grounded, and an inverting input terminal of the second operational amplifier is connected in series with a ninth resistor and VOUT;

[0071] The inverting input terminal of the second operational amplifier and the output terminal of the second operational amplifier are connected via a tenth resistor.

[0072] It is understandable that the signal conditioning circuit reverses the voltage output by the differential amplifier circuit and adds 3.3V to it, so that when the bus outputs a negative voltage when the vehicle battery is reversely connected, the voltage value input to the processor is still a positive voltage and can be collected by the processor. Figure 4 The voltage amplifier circuit shown is composed of a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a thirteenth resistor R13, a fourteenth resistor R14, and an operational amplifier U2B, wherein U2B is a rail-to-rail operational amplifier SGM8270, powered by a dual power supply of ±5V, and functions as an inverting amplifier with resistors R9, R10, and R11, and R13 and R14 form a superposition circuit.

[0073] It can be further understood that in the circuit, R9 = R10, and R11 is the op amp balancing resistor, with a resistance of R9 / / R10. The resistance values of R9, R10, and R11 can be adjusted according to the actual usage scenario.

[0074] Figure 5 This is a first filtering and port protection circuit diagram of an embodiment of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the utility model, comprising: a twelfth resistor, a ninth capacitor and a first clamping diode;

[0075] One end of the twelfth resistor is connected to VOUT, and the other end of the twelfth resistor is connected to the first clamping diode;

[0076] One end of the ninth capacitor intersects the twelfth resistor and the first clamping diode at a point, and the other end of the ninth capacitor is grounded;

[0077] One end of the clamping diode is connected to a power supply, and the other end of the first clamping diode is grounded.

[0078] It is understandable that the first filtering and port protection circuit mainly filters the output signal of the front-stage differential amplifier circuit and protects the bus voltage AD sampling port on the processor to avoid damage. Figure 5 The first filtering and port protection circuit shown is composed of the twelfth resistor R12, the ninth capacitor C9, and the clamping diode D1. R12 and C9 form a low-pass filter. D1 is the bus voltage AD sampling port protection diode, which can clamp the voltage value of the VOUT-AD1 point between 3.3V and the reference point to prevent the processor bus voltage AD sampling port from being damaged in unexpected situations.

[0079] Figure 6 This is a second filtering and port protection circuit diagram of an embodiment of the vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit of the utility model, comprising: a tenth capacitor and a second clamping diode;

[0080] A tenth capacitor is connected to the second clamping diode;

[0081] One end of the tenth capacitor is connected to VOUT, and the other end of the tenth capacitor is grounded;

[0082] One end of the second clamping diode is connected to the power supply, and the other end of the second clamping diode is grounded.

[0083] It is understandable that the second filtering and port protection circuit mainly filters the output signal of the pre-stage signal conditioning circuit and protects the vehicle battery reverse connection detection sampling port on the processor to avoid damage. Figure 6 The second filtering and port protection circuit shown is composed of the tenth capacitor C10 and the clamping diode D2. The ninth capacitor C9 is a filter capacitor, and D2 is a protection diode for the vehicle battery reverse connection detection sampling port. It can clamp the voltage value of the VOUT-AD2 point between 3.3V and the reference point to prevent damage to the processor's vehicle battery reverse connection detection sampling port in unexpected situations.

[0084] The above are only preferred specific implementation methods of the present invention, but the protection scope of the present invention is not limited to this. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in the present invention should be covered by the protection scope of the present invention.

Claims

1. A vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit, characterized in that: include: Buck isolation circuit, differential amplifier circuit, signal conditioning circuit, first filtering and port protection circuit, second filtering and port protection circuit and processor; The output end of the step-down isolation circuit is connected to the input end of the differential amplifier circuit, the output end of the differential amplifier circuit is connected to the input end of the first filter and port protection circuit, and the output end of the first filter and port protection circuit is connected to the input end of the processor; The output end of the differential amplifier circuit is also connected to the input end of the second filtering and port protection circuit, and the output end of the second filtering and port protection circuit is connected to the input end of the processor.

2. The vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit according to claim 1, characterized in that: The processor includes: a bus voltage sampling port, which is connected to the output end of the first filtering and port protection circuit.

3. The vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit according to claim 1 or 2, characterized in that: The processor further includes: an on-board battery reverse connection detection port, which is connected to the output end of the second filter and port protection circuit.

4. The vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit according to claim 1, characterized in that: The step-down isolation circuit includes: an analog isolation chip, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a third capacitor; the model of the analog isolation chip is: NSI1312D; Pin 1 of the isolation chip is connected to the second capacitor and the positive electrode of VDC at one point, the other end of the second capacitor is connected to the negative electrode of VDC, pin 4 of the isolation chip is connected to the negative electrode of VDC, pin 5 of the isolation chip is grounded, pin 6 of the isolation chip is connected to the negative electrode of VOUT, pin 7 of the isolation chip is connected to the positive electrode of VOUT, and pin 8 of the isolation chip is connected to the third capacitor and the positive electrode of VDC at one point; Pins 3 and 4 of the isolation chip are connected to the two ends of the first capacitor respectively; The second resistor, the third resistor and the fourth resistor are connected in series with the first capacitor; The first resistor, the second resistor and the third resistor are connected to one point; One end of the first resistor is connected to the positive electrode of VDC; One end of the fourth resistor is connected to the negative electrode of VDC.

5. The vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit according to claim 4, characterized in that: One end of the third capacitor is grounded.

6. The vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit according to claim 1, characterized in that: The differential amplifier circuit includes: a first operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor and an eighth capacitor; The positive power supply terminal of the first operational amplifier is connected in series with the seventh capacitor and GND, the negative power supply terminal of the first operational amplifier is connected in series with the eighth capacitor and GND, the output terminal of the first operational amplifier is connected in series with the eighth resistor and the inverting input terminal of the first operational amplifier, and the non-inverting input terminal of the first operational amplifier is connected in series with the seventh resistor and the fifth capacitor; One end of the fourth capacitor is connected to the fifth capacitor, and the other end of the fourth capacitor is connected to the sixth capacitor; One end of the fifth resistor is connected to the positive electrode of VOUT, and the other end of the fifth resistor intersects the fifth capacitor and the fourth capacitor at a point; One end of the sixth resistor is connected to the negative electrode of VOUT, and the other end of the sixth resistor intersects the fourth capacitor and the sixth capacitor at a point.

7. The vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit according to claim 1, characterized in that: The signal conditioning circuit includes: a second operational amplifier, a ninth resistor, a tenth resistor, an eleventh resistor, a thirteenth resistor, and a fourteenth resistor; An output terminal of the second operational amplifier is connected in series with a fourteenth resistor and a thirteenth resistor, a non-inverting input terminal of the second operational amplifier is connected to an eleventh resistor and is grounded, and an inverting input terminal of the second operational amplifier is connected in series with a ninth resistor and VOUT; The inverting input terminal of the second operational amplifier and the output terminal of the second operational amplifier are connected via a tenth resistor.

8. The vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit according to claim 1, characterized in that: The first filtering and port protection circuit includes: a twelfth resistor, a ninth capacitor and a first clamping diode; One end of the twelfth resistor is connected to VOUT, and the other end of the twelfth resistor is connected to the first clamping diode; One end of the ninth capacitor intersects the twelfth resistor and the first clamping diode at a point, and the other end of the ninth capacitor is grounded; One end of the clamping diode is connected to a power supply, and the other end of the first clamping diode is grounded.

9. The vehicle-mounted battery reverse connection detection and bus voltage acquisition circuit according to claim 1, characterized in that: The second filtering and port protection circuit includes: a tenth capacitor and a second clamping diode; A tenth capacitor is connected to the second clamping diode; One end of the tenth capacitor is connected to VOUT, and the other end of the tenth capacitor is grounded; One end of the second clamping diode is connected to the power supply, and the other end of the second clamping diode is grounded.

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