Sensor signal processing circuit and signal processing device

Abstract

The utility model relates to the technical field of electronics, in particular to a sensor signal processing circuit and a signal processing device. The signal processing circuit comprises a signal amplification circuit, a filter circuit, an analog-to-digital conversion circuit and a power supply circuit. The input end of the signal amplification circuit is used for receiving a sensor, the output end of the signal amplification circuit is connected with the input end of the filter circuit, and the output end of the filter circuit is connected with the input end of the analog-to-digital conversion circuit; the output end of the power supply circuit is connected with power supply terminals of the signal amplification circuit, the filter circuit and the analog-to-digital conversion circuit. Firstly, a signal amplification circuit is adopted to amplify an analog voltage signal output by an ultrasonic sensor, then a filter circuit is adopted to filter the amplified analog voltage signal, and finally an analog-to-digital conversion circuit is adopted to convert the filtered analog signal into a digital signal which can be directly read by a microprocessor. And the application scene of the ultrasonic sensor is expanded.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a sensor signal processing circuit and a signal processing device. Background Art

[0002] Ultrasonic probes are widely used in industries such as water conservancy and electric power, with ultrasonic sensors primarily used for defect detection. However, conventional ultrasonic sensors employ a piezoelectric structure, resulting in weak electrical signals. Typically, ultrasonic sensors output signals ranging from a few millivolts to tens of millivolts, with high output impedance and very weak load capacity. Furthermore, their bandwidth is centered around 40kHz, significantly limiting their practical application. Summary of the Invention

[0003] The present application provides a sensor signal processing circuit and a signal processing device to solve the technical problem in the related art that ultrasonic sensors are subject to significant limitations when used in actual scenarios.

[0004] In a first aspect, the present application provides a sensor signal processing circuit, the signal processing circuit comprising: a signal amplification circuit, a filtering circuit, an analog-to-digital conversion circuit, and a power supply circuit;

[0005] The input end of the signal amplifying circuit is used to receive the sensor, the output end of the signal amplifying circuit is connected to the input end of the filtering circuit, and the output end of the filtering circuit is connected to the input end of the analog-to-digital conversion circuit; the output end of the power supply circuit is connected to the power supply terminals of the signal amplifying circuit, the filtering circuit and the analog-to-digital conversion circuit;

[0006] The signal amplification circuit is used to receive the sensor signal and amplify the sensor signal; the filtering circuit is used to filter the amplified sensor signal; the analog-to-digital conversion circuit is used to convert the filtered sensor signal into a corresponding digital signal, and the output end of the analog-to-digital conversion circuit is used to output the converted digital signal; the power supply circuit is used to supply power to the signal amplification circuit, the filtering circuit and the analog-to-digital conversion circuit.

[0007] In some possible designs, the signal processing circuit further includes a voltage follower, wherein the input end of the voltage follower is used to be connected to the output end of the sensor, and the output end of the voltage follower is connected to the input end of the signal amplification circuit.

[0008] In some possible designs, the voltage follower includes a first operational amplifier, the non-inverting input terminal of the first operational amplifier is the input terminal of the voltage follower, the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier, the output terminal of the first operational amplifier is the output terminal of the voltage follower, and the power supply terminal of the first operational amplifier is connected to the output terminal of the power supply circuit.

[0009] In some possible designs, the signal amplification circuit includes a second operational amplifier, a first resistor, and a second resistor;

[0010] The non-inverting input terminal of the second operational amplifier is the input terminal of the signal amplification circuit, the inverting input terminal of the second operational amplifier is grounded through the first resistor, the inverting input terminal of the second operational amplifier is also connected to the output terminal of the second operational amplifier through the second resistor, and the output terminal of the second operational amplifier is the output terminal of the signal amplification circuit.

[0011] In some possible designs, the filtering circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a third operational amplifier, and a fourth operational amplifier;

[0012] Wherein, the first end of the third resistor is the input end of the filter circuit, the second end of the third resistor is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the inverting input end of the third operational amplifier, the non-inverting input end of the third operational amplifier is grounded, the first end of the fourth resistor is grounded, the second end of the fourth resistor is connected to the first end of the second capacitor, the second end of the second capacitor is connected to the first end of the fifth resistor, and the second end of the fifth resistor is connected to the inverting input end of the third operational amplifier; the second end of the second capacitor is also connected to the output end of the third operational amplifier;

[0013] The output end of the third operational amplifier is connected to the first end of the sixth resistor, the second end of the sixth resistor is connected to the first end of the third capacitor, the second end of the third capacitor is connected to the inverting input end of the fourth operational amplifier, the non-inverting input end of the fourth operational amplifier is grounded, the first end of the seventh resistor is grounded, the second end of the seventh resistor is connected to the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the output end of the fourth operational amplifier, the first end of the eighth resistor is connected to the second end of the fourth capacitor, and the second end of the eighth resistor is connected to the inverting input end of the fourth operational amplifier.

[0014] In some possible designs, the power supply circuit includes a voltage reversing circuit, which includes a switching power supply chip, a first inductor L1, a first diode, a fifth capacitor C8, a sixth capacitor C9, a seventh capacitor C10, an eighth capacitor C11, a ninth resistor R5, a tenth resistor R6, and an eleventh resistor R7;

[0015] A first end of the first inductor is grounded, and a second end of the first inductor is connected to an output pin of a switch transmitter inside the switching power supply chip. A first end of the sixth capacitor is used to receive a negative voltage signal, and a second end of the sixth capacitor is grounded. The second end of the sixth capacitor is also connected to the anode of the first diode, and the cathode of the first diode is also connected to the output pin of the switch transmitter inside the switching power supply chip. A first end of the fifth capacitor C8 is connected to a timing capacitor pin of the switching power supply chip, a second end of the fifth capacitor C8 is connected to a first end of the seventh capacitor C10, and a second end of the seventh capacitor is grounded. A ground pin of the switching power supply chip is connected to the first end of the seventh capacitor C10.

[0016] The feedback pin of the switching power supply chip is connected to the first end of the tenth resistor R6, the second end of the tenth resistor R6 is grounded, and the feedback pin of the switching power supply chip is also connected to the first end of the ninth resistor R5, and the second end of the ninth resistor R5 is used to receive the negative voltage signal; the current limiting detection input pin of the switching power supply chip is connected to the first end of the eleventh resistor R7, the second end of the eleventh resistor R7 is grounded through the eighth capacitor C11, and the second end of the eleventh resistor R7 is also used to receive the positive voltage signal; the internal switch collector input pin of the switching power supply chip is also connected to the collector input pin and the current limiting detection input pin.

[0017] In some possible designs, the switching power supply chip is MC34063.

[0018] In some possible designs, the analog-to-digital conversion circuit includes an analog-to-digital converter and a peripheral circuit connected to the analog-to-digital converter.

[0019] In some possible designs, the analog-to-digital converter is AD9226.

[0020] In a second aspect, the present application further provides a sensor signal processing device, which includes the signal processing circuit as described above.

[0021] According to the signal processing circuit provided in the first aspect above, a signal amplification circuit is first used to amplify the analog voltage signal output by the ultrasonic sensor, and then a filtering circuit is used to filter the amplified analog voltage signal. Finally, an analog-to-digital conversion circuit is used to convert the filtered analog signal into a digital signal that can be directly read by a microprocessor, thereby improving the application scenarios of the ultrasonic sensor.

[0022] The beneficial effects provided in the above-mentioned second aspect and the various possible designs of the above-mentioned second aspect can be referred to the beneficial effects brought about by the above-mentioned first aspect and the various possible implementation methods of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the sensor signal processing circuit structure provided in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of the voltage follower structure provided in an embodiment of the present application;

[0025] Figure 3 A schematic diagram of the structure of a signal amplification circuit provided in an embodiment of the present application;

[0026] Figure 4 A schematic diagram of the structure of the filter circuit provided in an embodiment of the present application;

[0027] Figure 5 A schematic diagram of the structure of a voltage reversal circuit provided in an embodiment of the present application;

[0028] Figure 6 A schematic diagram of the analog-to-digital conversion circuit structure provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a alone, b alone, or c alone can mean: a alone, b alone, c alone, a and b combined, a and c combined, b and c combined, or a, b, and c combined, where a, b, and c can be single or plural. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0030] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present application.

[0031] The terms "connected" and "connect" should be interpreted broadly. For example, "connected" or "connected" in a circuit structure can refer not only to a physical connection, but also to an electrical connection or a signal connection. For example, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate component, as long as the circuit is interconnected. It can also refer to internal connectivity between two components. Signal connection can refer not only to signal connection through circuits but also to signal connection through media, such as radio waves. Those skilled in the art will understand the specific meanings of the above terms in this application on a case-by-case basis.

[0032] In the related art, since the electrical signal output by the ultrasonic sensor is weak, it cannot be used directly in some actual scenarios and signal conditioning is required. For this reason, this application proposes a sensor signal processing circuit and a signal processing device. The signal processing circuit adopts a signal amplification circuit, a filtering circuit and an analog-to-digital conversion circuit, which can convert the analog signal output by the ultrasonic sensor into an 8-bit digital signal that can be directly read by the microprocessor, greatly improving the application scenarios of the ultrasonic sensor.

[0033] Figure 1 For a schematic diagram of the sensor signal processing circuit structure provided in the embodiment of the present application, please refer to Figure 1 As shown, the signal processing circuit includes: a signal amplifying circuit 10 , a filtering circuit 20 , an analog-to-digital conversion circuit 30 and a power supply circuit 40 .

[0034] Among them, the input end of the signal amplifying circuit 10 is used to receive the sensor, the output end of the signal amplifying circuit 10 is connected to the input end of the filtering circuit 20, and the output end of the filtering circuit 20 is connected to the input end of the analog-to-digital conversion circuit 30; the output end of the power supply circuit 40 is connected to the power supply terminals of the signal amplifying circuit 10, the filtering circuit 20 and the analog-to-digital conversion circuit 30.

[0035] Among them, the signal amplification circuit 10 is used to receive the sensor signal and amplify the sensor signal; the filtering circuit 20 is used to filter the amplified sensor signal; the analog-to-digital conversion circuit 30 is used to convert the filtered sensor signal into a corresponding digital signal, and the output end of the analog-to-digital conversion circuit 30 is used to output the converted digital signal; the power supply circuit 40 is used to supply power to the signal amplification circuit 10, the filtering circuit 20 and the analog-to-digital conversion circuit 30.

[0036] In some embodiments, the signal processing circuit further includes a voltage follower 50 , wherein the input end of the voltage follower 50 is connected to the output end of the ultrasonic sensor, and the output end of the voltage follower 50 is connected to the input end of the signal amplification circuit 10 .

[0037] Figure 2 For a schematic diagram of the voltage follower structure provided in the embodiment of this application, please refer to Figure 2 As shown, the voltage follower includes a first operational amplifier D1, the non-inverting input terminal of the first operational amplifier D1 is the input terminal of the voltage follower 50, the inverting input terminal of the first operational amplifier D2 is connected to the output terminal of the first operational amplifier D1, the output terminal of the first operational amplifier D1 is the output terminal of the voltage follower 50, and the power supply terminal of the first operational amplifier D1 is connected to the output terminal of the power supply circuit 40.

[0038] In some embodiments, the voltage follower 50 may be a commercially available voltage follower chip LM358.

[0039] Figure 3 For a schematic diagram of the structure of the signal amplification circuit provided in the embodiment of the present application, please refer to Figure 3 As shown, the signal amplification circuit 10 includes a second operational amplifier D2, a first resistor RF1 and a second resistor RF2. The non-inverting input terminal of the second operational amplifier D2 is the input terminal of the signal amplification circuit 10, the inverting input terminal of the second operational amplifier D2 is grounded through the first resistor RF1, and the inverting input terminal of the second operational amplifier D2 is also connected to the output terminal of the second operational amplifier D2 through the second resistor RF2. The output terminal of the second operational amplifier D2 is the output terminal of the signal amplification circuit 10.

[0040] In some embodiments, the second operational amplifier D2 may be an ADA4622 operational amplifier. The ADA4622 operational amplifier performs follow processing on the input sensor signal signal_in and outputs a signal signal_follow.

[0041] In this embodiment, a signal amplifier circuit 10 amplifies the sensor's output voltage signal by approximately 10 times before passing through the filter circuit 20. This signal amplifier circuit utilizes the ADA4622 chip. The ADA4622 chip features a high slew rate, with an open-loop gain exceeding 40dB in the 36-44kHz frequency range and a phase shift of approximately 900. This prevents significant distortion of the voltage signal after amplification by the ADA4622 chip. To filter out frequencies outside the 36-44kHz range, a bandpass filter circuit can also be constructed using the ADA4622 chip. Because the MFB multi-feedback filter circuit has excellent attenuation characteristics, a multi-feedback circuit is used as a bandpass filter to filter out noise and further amplify the signal by 10 times. The signal amplifier circuit 10 amplifies the input signal signal_follow and outputs the amplified signal signal.

[0042] Figure 4 For a schematic diagram of the structure of the filter circuit provided in the embodiment of the present application, please refer to Figure 4 As shown, the filtering circuit includes a third resistor RA1, a fourth resistor RA3, a fifth resistor RA2, a sixth resistor RB1, a seventh resistor RB2, an eighth resistor RB3, a first capacitor CA1, a second capacitor CA2, a third capacitor CB1, a fourth capacitor CB2, a third operational amplifier D3 and a fourth operational amplifier D4.

[0043] Among them, the first end of the third resistor RA1 is the input end of the filter circuit 20, the second end of the third resistor RA1 is connected to the first end of the first capacitor CA1, the second end of the first capacitor CA1 is connected to the inverting input end of the third operational amplifier D3, the non-inverting input end of the third operational amplifier D3 is grounded, the first end of the fourth resistor RA3 is grounded, the second end of the fourth resistor RA3 is connected to the first end of the second capacitor CA2, the second end of the second capacitor RA3 is connected to the first end of the fifth resistor RA2, and the second end of the fifth resistor RA2 is connected to the inverting input end of the third operational amplifier D3; the second end of the second capacitor CA2 is also connected to the output end out_A of the third operational amplifier.

[0044] Among them, the output end of the third operational amplifier D3 is connected to the first end of the sixth resistor RB1, the second end of the sixth resistor RB1 is connected to the first end of the third capacitor CB1, the second end of the third capacitor CB1 is connected to the inverting input end of the fourth operational amplifier D4, the non-inverting input end of the fourth operational amplifier D4 is grounded, the first end of the seventh resistor RB2 is grounded, the second end of the seventh resistor RB2 is connected to the first end of the fourth capacitor CB2, the second end of the fourth capacitor CB2 is connected to the output end of the fourth operational amplifier D4, the first end of the eighth resistor RB3 is connected to the second end of the fourth capacitor CB2, the second end of the eighth resistor RB3 is connected to the inverting input end of the fourth operational amplifier D4, and the output end out_B of the fourth operational amplifier D4 is the output end of the filter circuit 20.

[0045] The filter circuit 20 filters the amplified sensor signal signal to obtain a filtered signal signal_2. In this embodiment, the signal amplifier circuit 10 amplifies the signal output by the ultrasonic sensor, and then captures the ultrasonic signal with a frequency range of 36kHz to 44kHz through a bandpass filter.

[0046] The power supply circuit 40 includes a voltage reverse circuit. Figure 5 For a schematic diagram of the voltage reversal circuit provided in the embodiment of the present application, see Figure 5 As shown, the voltage reversing circuit 40 includes a switching power supply chip U3, a first inductor L1, a first diode D5, a fifth capacitor C8, a sixth capacitor C9, a seventh capacitor C10, an eighth capacitor C11, a ninth resistor R5, a tenth resistor R6 and an eleventh resistor R7.

[0047] Among them, the first end of the first inductor L1 is grounded, the second end of the first inductor L1 is connected to the internal switch transmitter output pin SE of the switching power supply chip U3, the first end of the sixth capacitor C9 is used to receive a negative voltage signal, specifically the negative voltage signal can be -5V, the second end of the sixth capacitor C9 is grounded, the second end of the sixth capacitor C9 is also connected to the positive electrode of the first diode D5, and the negative electrode of the first diode D5 is also connected to the internal switch transmitter output pin SE of the switching power supply chip U3; the first end of the fifth capacitor C8 is connected to the timing capacitor pin TC of the switching power supply chip U3, the second end of the fifth capacitor C8 is connected to the first end of the seventh capacitor C10, and the second end of the seventh capacitor C10 is grounded; the ground pin GND of the switching power supply chip U3 is connected to the first end of the seventh capacitor C10. The feedback pin FB of the switching power supply chip U3 is connected to the first end of the tenth resistor R6, the second end of the tenth resistor R6 is grounded, and the feedback pin FB of the switching power supply chip U3 is also connected to the first end of the ninth resistor R5, and the second end of the ninth resistor R5 is used to receive a negative voltage signal; the current limiting detection input pin IPK of the switching power supply chip U3 is connected to the first end of the eleventh resistor R7, the second end of the eleventh resistor R7 is grounded through the eighth capacitor C11, and the second end of the eleventh resistor R7 is also used to receive a positive voltage signal +5V; the internal switch collector input pin SC of the switching power supply chip U3 is also connected to the collector input pin DRI and the current limiting detection input pin IPK.

[0048] In some embodiments, the switching power supply chip U3 may be an MC34063 chip. The switching power supply chip U3 outputs +5V and -5V supply voltage signals to power the first operational amplifier D1, the second operational amplifier D2, the third operational amplifier D3, the fourth operational amplifier D4, and the analog-to-digital converter U7.

[0049] When the internal switch tube of the chip MC34063 is turned on, current flows to ground through pins 1 and 2 of the MC34063 and the first inductor L1. The first inductor L1 can store energy. At this time, the sixth capacitor C9 provides energy to the load. When the internal switch tube of the chip MC34063 is turned off, since the current flowing through the first inductor L1 cannot change suddenly, the first diode D5 acts as a freewheeling diode and is turned on. At this time, the first inductor L1 supplies power to the load and the sixth capacitor C9 through the first diode D5, outputting a negative voltage.

[0050] Figure 6 For a schematic diagram of the analog-to-digital conversion circuit structure provided in the embodiment of the present application, please refer to Figure 6 As shown, the analog-to-digital conversion circuit 30 includes an analog-to-digital converter U7 and related peripheral circuits connected to the analog-to-digital converter U7.

[0051] In some embodiments, the analog-to-digital converter U7 can use an analog-to-digital conversion chip with model AD9226. The output end of the filtering circuit 20 is connected to the input ends VINA and VINB of the analog-to-digital converter U7, and the filtered sensor signal signal is input into the analog-to-digital converter U7. The output ends BIT1~BIT8 of the analog-to-digital converter U7 are used to output the converted 8-bit digital signal.

[0052] Figure 6 The resistors R18, R19, R20, R21, R22, and R23, and the capacitors C14, C15, C16, C17, C18, C19, and C20 together constitute the relevant peripheral circuits of the analog-to-digital converter.

[0053] It can be seen that according to the signal processing circuit provided in this application, the signal amplification circuit 10 is first used to amplify the analog voltage signal output by the ultrasonic sensor, and then the filter circuit 20 is used to filter the amplified analog voltage signal. Finally, the analog-to-digital conversion circuit 30 converts the filtered analog signal into an 8-bit digital signal that can be directly read by the microprocessor, which greatly improves the application scenarios of the ultrasonic sensor.

[0054] This embodiment further provides a sensor signal processing device, which includes the signal processing circuit described above. In addition, the processing device may also include an insulating housing, wiring terminals and other related structures, which will not be described in detail here.

[0055] Finally, it should be noted that the above embodiments are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A sensor signal processing circuit, characterized in that: The signal processing circuit includes: a signal amplification circuit, a filtering circuit, an analog-to-digital conversion circuit and a power supply circuit; The input end of the signal amplifying circuit is used to receive the sensor, the output end of the signal amplifying circuit is connected to the input end of the filtering circuit, and the output end of the filtering circuit is connected to the input end of the analog-to-digital conversion circuit; the output end of the power supply circuit is connected to the power supply terminals of the signal amplifying circuit, the filtering circuit and the analog-to-digital conversion circuit; The signal amplification circuit is used to receive the sensor signal and amplify the sensor signal; the filtering circuit is used to filter the amplified sensor signal; the analog-to-digital conversion circuit is used to convert the filtered sensor signal into a corresponding digital signal, and the output end of the analog-to-digital conversion circuit is used to output the converted digital signal; the power supply circuit is used to supply power to the signal amplification circuit, the filtering circuit, and the analog-to-digital conversion circuit; The signal processing circuit further includes a voltage follower, wherein the input end of the voltage follower is connected to the output end of the sensor, and the output end of the voltage follower is connected to the input end of the signal amplification circuit; The voltage follower includes a first operational amplifier, the non-inverting input terminal of the first operational amplifier is the input terminal of the voltage follower, the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier, the output terminal of the first operational amplifier is the output terminal of the voltage follower, and the power supply terminal of the first operational amplifier is connected to the output terminal of the power supply circuit.

2. The signal processing circuit according to claim 1, wherein: The signal amplifying circuit includes a second operational amplifier, a first resistor and a second resistor; The non-inverting input terminal of the second operational amplifier is the input terminal of the signal amplification circuit, the inverting input terminal of the second operational amplifier is grounded through the first resistor, the inverting input terminal of the second operational amplifier is also connected to the output terminal of the second operational amplifier through the second resistor, and the output terminal of the second operational amplifier is the output terminal of the signal amplification circuit.

3. The signal processing circuit according to claim 1, wherein: The filtering circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a third operational amplifier, and a fourth operational amplifier; Wherein, the first end of the third resistor is the input end of the filter circuit, the second end of the third resistor is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the inverting input end of the third operational amplifier, the non-inverting input end of the third operational amplifier is grounded, the first end of the fourth resistor is grounded, the second end of the fourth resistor is connected to the first end of the second capacitor, the second end of the second capacitor is connected to the first end of the fifth resistor, and the second end of the fifth resistor is connected to the inverting input end of the third operational amplifier; the second end of the second capacitor is also connected to the output end of the third operational amplifier; The output end of the third operational amplifier is connected to the first end of the sixth resistor, the second end of the sixth resistor is connected to the first end of the third capacitor, the second end of the third capacitor is connected to the inverting input end of the fourth operational amplifier, the non-inverting input end of the fourth operational amplifier is grounded, the first end of the seventh resistor is grounded, the second end of the seventh resistor is connected to the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the output end of the fourth operational amplifier, the first end of the eighth resistor is connected to the second end of the fourth capacitor, and the second end of the eighth resistor is connected to the inverting input end of the fourth operational amplifier.

4. The signal processing circuit according to claim 1, wherein: The power supply circuit includes a voltage reverse circuit, which includes a switching power supply chip, a first inductor L1, a first diode, a fifth capacitor C8, a sixth capacitor C9, a seventh capacitor C10, an eighth capacitor C11, a ninth resistor R5, a tenth resistor R6, and an eleventh resistor R7; A first end of the first inductor is grounded, and a second end of the first inductor is connected to an output pin of a switch transmitter inside the switching power supply chip. A first end of the sixth capacitor is used to receive a negative voltage signal, and a second end of the sixth capacitor is grounded. The second end of the sixth capacitor is also connected to the anode of the first diode, and the cathode of the first diode is also connected to the output pin of the switch transmitter inside the switching power supply chip. A first end of the fifth capacitor C8 is connected to a timing capacitor pin of the switching power supply chip, a second end of the fifth capacitor C8 is connected to a first end of the seventh capacitor C10, and a second end of the seventh capacitor is grounded. A ground pin of the switching power supply chip is connected to the first end of the seventh capacitor C10. The feedback pin of the switching power supply chip is connected to the first end of the tenth resistor R6, the second end of the tenth resistor R6 is grounded, and the feedback pin of the switching power supply chip is also connected to the first end of the ninth resistor R5, and the second end of the ninth resistor R5 is used to receive the negative voltage signal; the current limiting detection input pin of the switching power supply chip is connected to the first end of the eleventh resistor R7, the second end of the eleventh resistor R7 is grounded through the eighth capacitor C11, and the second end of the eleventh resistor R7 is also used to receive the positive voltage signal; the internal switch collector input pin of the switching power supply chip is also connected to the collector input pin and the current limiting detection input pin.

5. The signal processing circuit according to claim 4, characterized in that The model of the switching power supply chip is MC34063.

6. The signal processing circuit according to claim 1, wherein: The analog-to-digital conversion circuit includes an analog-to-digital converter and a peripheral circuit connected to the analog-to-digital converter.

7. The signal processing circuit according to claim 6, wherein: The model of the analog-to-digital converter is AD9226.

8. A sensor signal processing device, characterized in that: The method comprises the signal processing circuit according to any one of claims 1 to 7.

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