Current detection differential operational amplifier circuit

Abstract

The utility model is suitable for the technical field of analog electronics, and provides a current detection differential operational amplifier circuit, which comprises a first attenuation filter module, a signal amplification module and a first differential resistance-capacitance module, a first input end and a second input end of the first attenuation filtering module are respectively connected with two ends of a shunt, a first output end and a second output end of the first attenuation filtering module are respectively connected with the signal amplification module, and the first attenuation filtering module is used for carrying out primary filtering on a detection signal so as to eliminate same-frequency interference caused by a switching tube; the output end of the signal amplification module is connected with the input end of the first differential resistance-capacitance module, and the signal amplification module is used for amplifying the detection signal filtered by the attenuation filter circuit; and the output end of the first differential resistance-capacitance module outputs a differential signal to the processing module, and is used for converting the detection signal amplified by the signal amplification module into the differential signal for secondary filtering so as to eliminate coupling interference of stray capacitance on a line. According to the utility model, the problem of inaccurate current detection is solved.

Description

Technical Field

[0001] The utility model belongs to the field of analog electronic technology, and particularly relates to a current detection differential operational amplifier circuit. Background Art

[0002] Current detection is a common function in a circuit for monitoring current, and is widely used in fields such as motor control, power management, battery charging control, etc. Generally, a shunt is used in a current detection circuit to detect the battery current. Differential detection is used to obtain the voltage drop on the shunt, and the detected current is calculated in combination with the voltage-current ratio relationship of the shunt itself.

[0003] Currently, the voltage signal output from the current detection end is directly transmitted to the detection chip in a single-ended transmission manner.

[0004] In this way, the voltage signal will be coupled and interfered by the stray capacitance on the line and the same-frequency interference of the switching tube during the transmission process, resulting in an error in the voltage signal output from the current detection end during the process of being transmitted to the detection chip, and thus an error in the detected current calculated by the detection chip, and there is a problem of inaccurate current detection. Summary of the Utility Model

[0005] The purpose of the embodiment of the utility model is to provide a current detection differential operational amplifier circuit, aiming to solve the problem of inaccurate current detection.

[0006] The embodiment of the utility model is implemented as follows. A current detection differential operational amplifier circuit includes: a first attenuation and filtering module, a signal amplification module, and a first differential resistor-capacitor module;

[0007] The first input end and the second input end of the first attenuation and filtering module are respectively connected to both ends of the shunt, and the first output end and the second output end are respectively connected to the signal amplification module, and are used for filtering the detection signal once to eliminate the same-frequency interference brought by the switching tube;

[0008] The output end of the signal amplification module is connected to the input end of the first differential resistor-capacitor module, and is used for amplifying the detection signal filtered by the attenuation and filtering circuit;

[0009] The output end of the first differential resistor-capacitor module outputs a differential signal to the processing module, and is used for converting the detection signal amplified by the signal amplification module into a differential signal for secondary filtering to eliminate the coupling interference of the stray capacitance on the line.

[0010] Preferably, the first attenuation and filtering module includes a resistor R1, a resistor R10, a capacitor C2, a capacitor C10, and a capacitor C5;

[0011] One end of the resistor R1 is connected to one end of the shunt, and the other end is connected to the ground wire through the capacitor C2;

[0012] One end of the resistor R10 is connected to the end of the shunt that is not connected to the resistor R1, and the other end is connected to the ground wire through the capacitor C10;

[0013] One end of the capacitor C5 is connected to the end where the resistor R1 is connected to the capacitor C2, and the other end is connected to the end where the resistor R10 is connected to the capacitor C10.

[0014] Preferably, a second attenuation filtering module is provided between the first attenuation filtering module and the signal amplification module.

[0015] Preferably, the second attenuation filtering module includes a resistor R2, a resistor R12, a capacitor C3, a capacitor C11, and a capacitor C6;

[0016] One end of the resistor R2 is connected to the end where the resistor R1 is connected to the capacitor C2, and the other end is connected to the ground wire through the capacitor C3;

[0017] One end of the resistor R12 is connected to the end where the resistor R10 is connected to the capacitor C10, and the other end is connected to the ground wire through the capacitor C11;

[0018] One end of the capacitor C6 is connected to the end where the resistor R2 is connected to the capacitor C3, and the other end is connected to the end where the resistor R12 is connected to the capacitor C11.

[0019] Preferably, a third attenuation filtering module is provided between the second attenuation filtering module and the signal amplification module.

[0020] Preferably, the third attenuation filtering module includes a resistor R3, a resistor R11, a capacitor C4, a capacitor C12, and a capacitor C7;

[0021] One end of the resistor R3 is connected to the end where the resistor R2 is connected to the capacitor C3, and the other end is connected to the ground wire through the capacitor C4;

[0022] One end of the resistor R11 is connected to the end where the resistor R12 is connected to the capacitor C11, and the other end is connected to the ground wire through the capacitor C12;

[0023] One end of the capacitor C7 is connected to the end where the resistor R3 is connected to the capacitor C4, and the other end is connected to the end where the resistor R11 is connected to the capacitor C12.

[0024] Preferably, the signal amplification module includes an amplifier U1 and a resistor R5;

[0025] The -IN pin of the amplifier U1 is connected to the first output terminal of the first attenuation and filtering module, the +IN pin is connected to the second output terminal of the first attenuation and filtering module, the +VS pin is connected to the positive pole of the power supply module, the VOUT pin is connected to the input terminal of the first differential resistor-capacitor module, the REF pin is connected to the ground wire, and the -VS pin is connected to the negative pole of the power supply module;

[0026] The resistor R5 is connected between the two RG pins of the amplifier U1.

[0027] Preferably, the first differential resistor-capacitor module includes a resistor R6, a resistor R8, and a capacitor C8;

[0028] One end of the resistor R6 is connected to the VOUT pin of the amplifier U1, and the other end is connected to the processing module;

[0029] One end of the resistor R8 is connected to the ground wire, and the other end is connected to the processing module;

[0030] One end of the capacitor C8 is connected to the end of the resistor R6 that is not connected to the VOUT pin of the amplifier U1, and the other end is connected to the end of the resistor R8 that is not connected to the REF pin of the amplifier U1.

[0031] Preferably, a second differential resistor-capacitor module is provided between the first differential resistor-capacitor module and the processing module.

[0032] Preferably, the second differential resistor-capacitor module includes a resistor R7, a resistor R9, and a capacitor C9;

[0033] One end of the resistor R7 is connected to the end of the resistor R6 that is not connected to the VOUT pin of the amplifier U1, and the other end is connected to the processing module;

[0034] One end of the resistor R9 is connected to the end of the resistor R8 that is not connected to the ground wire, and the other end is connected to the processing module;

[0035] One end of the capacitor C9 is connected to the end of the resistor R7 that is not connected to the resistor R6, and the other end is connected to the end of the resistor R8 that is not connected to the resistor R9.

[0036] A current detection differential operational amplifier circuit provided by an embodiment of the present utility model obtains a detection signal of a shunt via a first attenuation and filtering module, performs primary filtering on the detection signal to eliminate the co-frequency interference brought by a switching tube, amplifies the detection signal filtered by the attenuation and filtering circuit via a signal amplification module, and converts the detection signal amplified by the signal amplification module into a differential signal via a first differential resistor-capacitor module for secondary filtering so as to eliminate the coupling interference of stray capacitance on the line. By doing so, it eliminates the coupling interference of stray capacitance on the line and the co-frequency interference of the switching tube during the transmission of the detection signal, reduces the error in the process of the voltage signal output by the current detection end being transmitted to the detection chip, and solves the problem of inaccurate current detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a circuit diagram of a current detection differential operational amplifier circuit provided by an embodiment of the present utility model;

[0038] Figure 2 is a circuit diagram of a current detection differential operational amplifier circuit provided by another embodiment of the present utility model; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0040] The following describes the specific implementation of the present utility model in detail with reference to specific embodiments.

[0041] As Figure 1 shown, a structural diagram of a current detection differential operational amplifier circuit provided by an embodiment of the present utility model includes: a first attenuation and filtering module, a signal amplification module, and a first differential resistor-capacitor module;

[0042] The first input terminal and the second input terminal of the first attenuation and filtering module are respectively connected to both ends of the shunt, and the first output terminal and the second output terminal are respectively connected to the signal amplification module, and are used for performing primary filtering on the detection signal to eliminate the co-frequency interference brought by the switching tube;

[0043] The output terminal of the signal amplification module is connected to the input terminal of the first differential resistor-capacitor module, and is used for amplifying the detection signal filtered by the attenuation and filtering circuit;

[0044] The output terminal of the first differential resistor-capacitor module outputs a differential signal to the processing module, and is used for converting the detection signal amplified by the signal amplification module into a differential signal for secondary filtering so as to eliminate the coupling interference of stray capacitance on the line.

[0045] In the embodiment of the present utility model, as Figure 1 shown, the first terminal P+ is the positive electrode of the power source for battery charging and discharging, the second terminal P- is the negative electrode of the power source for battery charging and discharging, the third terminal BATT+ is the positive electrode of the battery, and the fourth terminal BATT- is the negative electrode of the battery. Current flows in from the first terminal P+, through the shunt resistor R4, and into the battery from the third terminal BATT+ to complete the charging function. To complete current detection, it is necessary to collect the current passing through the shunt resistor R4. The current passing through the shunt resistor R4 can be obtained from the ratio of the voltage across the shunt resistor R4 to the shunt resistor. Therefore, the first input terminal and the second input terminal of the first attenuation filtering module are respectively connected to both ends of the shunt resistor, and the voltage difference across the shunt resistor is collected, that is, the detection signal is a voltage signal.

[0046] In the embodiment of the present utility model, the detection signal received by the signal amplification module is a voltage signal, that is, the voltage difference across the shunt resistor, and the voltage signal is amplified, and the output detection signal is still a voltage signal.

[0047] In the embodiment of the present utility model, the differential resistor-capacitor pair performs differential processing on the detection signal for secondary filtering, and two differential signals are output here.

[0048] In the embodiment of the present utility model, the processing module can be an MCU chip with an AD conversion function or a differential AD converter. The differential signals output by the first differential resistor-capacitor module are respectively transmitted to the non-inverting input terminal and the inverting input terminal of the processing module.

[0049] A current detection differential operational amplifier circuit provided by the embodiment of the present utility model obtains the detection signal of the shunt resistor through the first attenuation filtering module, performs primary filtering on the detection signal to eliminate the co-frequency interference brought by the switching tube, the signal amplification module amplifies the detection signal filtered by the attenuation filtering circuit, and the first differential resistor-capacitor module converts the detection signal amplified by the signal amplification module into differential signals for secondary filtering to eliminate the coupling interference of the stray capacitance on the line. This eliminates the coupling interference of the stray capacitance on the line and the co-frequency interference of the switching tube during the transmission of the detection signal, reduces the error in the process of transmitting the voltage signal output by the current detection end to the detection chip, and solves the problem of inaccurate current detection.

[0050] As Figure 1 shown, as a preferred embodiment of the present utility model, the first attenuation filtering module includes a resistor R1, a resistor R10, a capacitor C2, a capacitor C10, and a capacitor C5;

[0051] One end of the resistor R1 is connected to one end of the shunt resistor, and the other end is connected to the ground wire through the capacitor C2;

[0052] One end of the resistor R10 is connected to the end of the shunt that is not connected to the resistor R1, and the other end is connected to the ground wire through the capacitor C10;

[0053] One end of the capacitor C5 is connected to the end where the resistor R1 is connected to the capacitor C2, and the other end is connected to the end where the resistor R10 is connected to the capacitor C10.

[0054] In the embodiment of the present invention, the end of the resistor R1 connected to the shunt is the first input end of the first attenuation filtering module, and the end connected to the capacitor C2 is the first output end of the first attenuation filtering module. The end of the resistor R10 connected to the shunt is the second input end of the first attenuation filtering module, and the end connected to the capacitor C10 is the second output end of the first attenuation filtering module.

[0055] In the embodiment of the present invention, the resistor R1 and the capacitor C2 form a filtering circuit, and the resistor R10 and the capacitor C10 form a filtering circuit to filter the collected detection signal.

[0056] As Figure 2 shown, as a preferred embodiment of the present invention, a second attenuation filtering module is provided between the first attenuation filtering module and the signal amplification module.

[0057] In the embodiment of the present invention, if the PCB board is too large and the first attenuation filtering module cannot effectively eliminate the co-frequency interference brought by the switching tube, a second attenuation filtering module can be added between the first attenuation filtering module and the signal amplification module. The second attenuation filtering module is exactly the same as the first attenuation filtering module.

[0058] As Figure 2 shown, as a preferred embodiment of the present invention, the second attenuation filtering module includes a resistor R2, a resistor R12, a capacitor C3, a capacitor C11, and a capacitor C6;

[0059] One end of the resistor R2 is connected to the end where the resistor R1 is connected to the capacitor C2, and the other end is connected to the ground wire through the capacitor C3;

[0060] One end of the resistor R12 is connected to the end where the resistor R10 is connected to the capacitor C10, and the other end is connected to the ground wire through the capacitor C11;

[0061] One end of the capacitor C6 is connected to the end where the resistor R2 is connected to the capacitor C3, and the other end is connected to the end where the resistor R12 is connected to the capacitor C11.

[0062] In the embodiment of the present utility model, one end of the resistor R2 connected to the resistor R1 is the first input end of the second attenuation and filtering module, and one end connected to the capacitor C3 is the first output end of the second attenuation and filtering module. One end of the resistor R12 connected to the resistor R10 is the second input end of the second attenuation and filtering module, and one end connected to the capacitor C11 is the second output end of the second attenuation and filtering module.

[0063] In the embodiment of the present utility model, if a second attenuation and filtering module is added between the first attenuation and filtering module and the signal amplification module, then the first output end and the second output end of the first attenuation and filtering module are no longer connected to the signal amplification module. Instead, the first output end of the first attenuation and filtering module is connected to the first input end of the second attenuation and filtering module, the second output end of the first attenuation and filtering module is connected to the second input end of the second attenuation and filtering module, and the first output end and the second output end of the second attenuation and filtering module are respectively connected to the signal amplification module. At this time, the first attenuation and filtering module has no direct connection relationship with the signal amplification module, but is connected to the signal amplification module through the second attenuation and filtering module.

[0064] As Figure 2 shown, as a preferred embodiment of the present utility model, a third attenuation and filtering module is provided between the second attenuation and filtering module and the signal amplification module.

[0065] In the embodiment of the present utility model, if the PCB board is too large and the first attenuation and filtering module and the second attenuation and filtering module cannot well eliminate the co-frequency interference brought by the switching tube, a third attenuation and filtering module can be added between the second attenuation and filtering module and the signal amplification module. The third attenuation and filtering module is exactly the same as the first attenuation and filtering module and the second attenuation and filtering module. Similarly, more attenuation and filtering modules can be provided.

[0066] As Figure 2 shown, as a preferred embodiment of the present utility model, the third attenuation and filtering module includes a resistor R3, a resistor R11, a capacitor C4, a capacitor C12, and a capacitor C7;

[0067] One end of the resistor R3 is connected to the end of the resistor R2 connected to the capacitor C3, and the other end is connected to the ground wire through the capacitor C4;

[0068] One end of the resistor R11 is connected to the end of the resistor R12 connected to the capacitor C11, and the other end is connected to the ground wire through the capacitor C12;

[0069] One end of the capacitor C7 is connected to the end of the resistor R3 connected to the capacitor C4, and the other end is connected to the end of the resistor R11 connected to the capacitor C12.

[0070] In the embodiment of the present utility model, one end of the resistor R3 connected to the resistor R2 is the first input end of the third attenuation filtering module, and one end connected to the capacitor C4 is the first output end of the third attenuation filtering module. One end of the resistor R11 connected to the resistor R12 is the second input end of the third attenuation filtering module, and one end connected to the capacitor C12 is the second output end of the third attenuation filtering module.

[0071] In the embodiment of the present utility model, if a third attenuation filtering module is added between the second attenuation filtering module and the signal amplification module, then the first output end and the second output end of the second attenuation filtering module are no longer connected to the signal amplification module. Instead, the first output end of the second attenuation filtering module is connected to the first input end of the third attenuation filtering module, the second output end of the second attenuation filtering module is connected to the second input end of the third attenuation filtering module, and the first output end and the second output end of the third attenuation filtering module are respectively connected to the signal amplification module. At this time, the first attenuation filtering module, the second attenuation filtering module and the signal amplification module have no direct connection relationship, and the first attenuation filtering module is connected to the signal amplification module through the second attenuation filtering module and the third attenuation filtering module.

[0072] As Figure 1 shown, as a preferred embodiment of the present utility model, the signal amplification module includes an amplifier U1 and a resistor R5;

[0073] The -IN pin of the amplifier U1 is connected to the first output end of the first attenuation filtering module, the +IN pin is connected to the second output end of the first attenuation filtering module, the +VS pin is connected to the positive pole of the power supply module, the VOUT pin is connected to the input end of the first differential resistor-capacitor module, the REF pin is connected to the ground wire, and the -VS pin is connected to the negative pole of the power supply module;

[0074] The resistor R5 is connected between the two RG pins of the amplifier U1.

[0075] In the embodiment of the present utility model, the signal amplification module has two input terminals. The first input terminal is the -IN pin of the amplifier U1, and the second input terminal is the +IN pin of the amplifier U1. Essentially, the first output terminal of the attenuation and filtering module is connected to the first input terminal of the signal amplification module, and the second output terminal of the attenuation and filtering module is connected to the second input terminal of the signal amplification module. If there is only one attenuation and filtering module, i.e., the first attenuation and filtering module, between the shunt and the signal amplification module, then the -IN pin of the amplifier U1 is connected to the end where the resistor R1 is connected to the capacitor C2, and the +IN pin is connected to the end where the resistor R10 is connected to the capacitor C10. If there are two attenuation and filtering modules, i.e., the first attenuation and filtering module and the second attenuation and filtering module, between the shunt and the signal amplification module, then the -IN pin of the amplifier U1 is connected to the first output terminal of the second attenuation and filtering module, and the +IN pin is connected to the second output terminal of the second attenuation and filtering module, that is, the -IN pin of the amplifier U1 is connected to the end where the resistor R2 is connected to the capacitor C3, and the +IN pin is connected to the end where the resistor R12 is connected to the capacitor C11. If there are three attenuation and filtering modules, i.e., the first attenuation and filtering module, the second attenuation and filtering module, and the third attenuation and filtering module, between the shunt and the signal amplification module, then the -IN pin of the amplifier U1 is connected to the first output terminal of the third attenuation and filtering module, and the +IN pin is connected to the second output terminal of the third attenuation and filtering module, that is, the -IN pin of the amplifier U1 is connected to the end where the resistor R3 is connected to the capacitor C4, and the +IN pin is connected to the end where the resistor R11 is connected to the capacitor C12.

[0076] In the embodiment of the present utility model, the VOUT pin of the amplifier U1 is the output terminal of the signal amplifier.

[0077] In the embodiment of the present utility model, the power supply module provides the operating voltage for the amplifier U1, which can be a 5V DC voltage.

[0078] In the embodiment of the present utility model, the resistor R5 is used to adjust the gain effect of the amplifier U1.

[0079] As Figure 1 shown, as a preferred embodiment of the present utility model, the first differential resistor-capacitor module includes a resistor R6, a resistor R8, and a capacitor C8;

[0080] One end of the resistor R6 is connected to the VOUT pin of the amplifier U1, and the other end is connected to the processing module;

[0081] One end of the resistor R8 is connected to the ground wire, and the other end is connected to the processing module;

[0082] One end of the capacitor C8 is connected to the end of the resistor R6 that is not connected to the VOUT pin of the amplifier U1, and the other end is connected to the end of the resistor R8 that is not connected to the REF pin of the amplifier U1.

[0083] In the embodiment of the present invention, the end of the resistor R6 connected to the VOUT pin of the amplifier U1 is the input end of the first differential resistor-capacitor module. The first differential resistor-capacitor module has two output ends. One output is the end of the resistor R6 connected to the capacitor C8, and this output end is connected to the non-inverting input end of the processing module; the other output end is the end of the resistor R8 connected to the capacitor C8, and this output end is connected to the inverting input end of the processing module.

[0084] In the embodiment of the present invention, the differential signal output from the first differential resistor-capacitor module to the processing module is essentially the voltage across the capacitor C8.

[0085] As Figure 2 shown, as a preferred embodiment of the present invention, a second differential resistor-capacitor module is provided between the first differential resistor-capacitor module and the processing module.

[0086] In the embodiment of the present invention, if the first differential resistor-capacitor module cannot effectively eliminate the coupling interference of the stray capacitance on the line, a second differential resistor-capacitor module can be added between the first differential resistor-capacitor module and the processing module. The second differential resistor-capacitor module is exactly the same as the first differential resistor-capacitor module. Similarly, more differential resistor-capacitor modules can be added. Preferably, two differential resistor-capacitor modules are provided in the current detection differential operational amplifier circuit, namely the first differential resistor-capacitor module and the second differential resistor-capacitor module.

[0087] As Figure 2 shown, as a preferred embodiment of the present invention, the second differential resistor-capacitor module includes a resistor R7, a resistor R9, and a capacitor C9;

[0088] One end of the resistor R7 is connected to the end of the resistor R6 that is not connected to the VOUT pin of the amplifier U1, and the other end is connected to the processing module;

[0089] One end of the resistor R9 is connected to the end of the resistor R8 that is not connected to the ground wire, and the other end is connected to the processing module;

[0090] One end of the capacitor C9 is connected to the end of the resistor R7 that is not connected to the resistor R6, and the other end is connected to the end of the resistor R8 that is not connected to the resistor R9.

[0091] In the embodiment of the present utility model, if a second differential resistor-capacitor module is added between the first differential resistor-capacitor module and the processing module, then the first output terminal and the second output terminal of the first differential resistor-capacitor module are no longer connected to the processing module. Instead, the first output terminal of the first differential resistor-capacitor module is connected to the first input terminal of the second differential resistor-capacitor module, and the second output terminal of the first differential resistor-capacitor module is connected to the second input terminal of the second differential resistor-capacitor module. The first output terminal and the second output terminal of the second differential resistor-capacitor module output differential signals to the processing module. At this time, the first differential resistor-capacitor module has no direct connection relationship with the processing module, but is connected to the processing module through the second attenuation and filtering module.

[0092] In the embodiment of the present utility model, the end of the resistor R7 connected to the resistor R6 is the input terminal of the second differential resistor-capacitor module. The second differential resistor-capacitor module has two output terminals. One output is the end of the resistor R7 connected to the capacitor C9, and this output terminal is connected to the non-inverting input terminal of the processing module; the other output terminal is the end of the resistor R9 connected to the capacitor C9, and this output terminal is connected to the inverting input terminal of the processing module.

[0093] In the embodiment of the present utility model, the differential signal received by the processing module is essentially the voltage across the capacitor C9.

[0094] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A current detection differential operational amplifier circuit, characterized in that The current detection differential operational amplifier circuit includes: a first attenuation and filtering module, a signal amplification module, and a first differential resistor-capacitor module; The first input terminal and the second input terminal of the first attenuation and filtering module are respectively connected to both ends of the shunt, and the first output terminal and the second output terminal are respectively connected to the signal amplification module, and are used for performing primary filtering on the detection signal to eliminate the co-frequency interference brought by the switching tube; The output terminal of the signal amplification module is connected to the input terminal of the first differential resistor-capacitor module, and is used for amplifying the detection signal filtered by the attenuation and filtering circuit; The output terminal of the first differential resistor-capacitor module outputs a differential signal to the processing module, and is used for converting the detection signal amplified by the signal amplification module into a differential signal for secondary filtering to eliminate the coupling interference of the stray capacitance on the line.

2. The current detection differential operational amplifier circuit according to claim 1, wherein The first attenuation and filtering module includes a resistor R1, a resistor R10, a capacitor C2, a capacitor C10, and a capacitor C5; One end of the resistor R1 is connected to one end of the shunt, and the other end is connected to the ground wire through the capacitor C2; One end of the resistor R10 is connected to the end of the shunt that is not connected to the resistor R1, and the other end is connected to the ground wire through the capacitor C10; One end of the capacitor C5 is connected to the end where the resistor R1 is connected to the capacitor C2, and the other end is connected to the end where the resistor R10 is connected to the capacitor C10.

3. The current detection differential operational amplifier circuit according to claim 2, characterized in that, A second attenuation and filtering module is provided between the first attenuation and filtering module and the signal amplification module.

4. The current detection differential operational amplifier circuit according to claim 3, wherein The second attenuation and filtering module includes a resistor R2, a resistor R12, a capacitor C3, a capacitor C11, and a capacitor C6; One end of the resistor R2 is connected to the end where the resistor R1 is connected to the capacitor C2, and the other end is connected to the ground wire through the capacitor C3; One end of the resistor R12 is connected to the end where the resistor R10 is connected to the capacitor C10, and the other end is connected to the ground wire through the capacitor C11; One end of the capacitor C6 is connected to the end where the resistor R2 is connected to the capacitor C3, and the other end is connected to the end where the resistor R12 is connected to the capacitor C11.

5. The current detection differential operational amplifier circuit according to claim 4, wherein A third attenuation and filtering module is provided between the second attenuation and filtering module and the signal amplification module.

6. The current detection differential operational amplifier circuit according to claim 5, wherein The third attenuation and filtering module includes a resistor R3, a resistor R11, a capacitor C4, a capacitor C12, and a capacitor C7; One end of the resistor R3 is connected to the end where the resistor R2 is connected to the capacitor C3, and the other end is connected to the ground wire through the capacitor C4; One end of the resistor R11 is connected to the end where the resistor R12 is connected to the capacitor C11, and the other end is connected to the ground wire through the capacitor C12; One end of the capacitor C7 is connected to the end where the resistor R3 is connected to the capacitor C4, and the other end is connected to the end where the resistor R11 is connected to the capacitor C12.

7. The current detection differential operational amplifier circuit according to claim 1, characterized in that, The signal amplification module includes an amplifier U1 and a resistor R5; The -IN pin of the amplifier U1 is connected to the first output terminal of the first attenuation and filtering module, the +IN pin is connected to the second output terminal of the first attenuation and filtering module, the +VS pin is connected to the positive pole of the power supply module, the VOUT pin is connected to the input terminal of the first differential resistor-capacitor module, the REF pin is connected to the ground wire, and the -VS pin is connected to the negative pole of the power supply module; The resistor R5 is connected between the two RG pins of the amplifier U1.

8. The current detection differential operational amplifier circuit according to claim 7, wherein The first differential resistor-capacitor module includes a resistor R6, a resistor R8, and a capacitor C8; One end of the resistor R6 is connected to the VOUT pin of the amplifier U1, and the other end is connected to the processing module; One end of the resistor R8 is connected to the ground wire, and the other end is connected to the processing module; One end of the capacitor C8 is connected to the end of the resistor R6 that is not connected to the VOUT pin of the amplifier U1, and the other end is connected to the end of the resistor R8 that is not connected to the REF pin of the amplifier U1.

9. The current detection differential operational amplifier circuit according to claim 8, wherein, A second differential resistor-capacitor module is provided between the first differential resistor-capacitor module and the processing module.

10. The current detection differential operational amplifier circuit according to claim 9, wherein The second differential resistor-capacitor module includes a resistor R7, a resistor R9, and a capacitor C9; One end of the resistor R7 is connected to the end of the resistor R6 that is not connected to the VOUT pin of the amplifier U1, and the other end is connected to the processing module; One end of the resistor R9 is connected to the end of the resistor R8 that is not connected to the ground wire, and the other end is connected to the processing module; One end of the capacitor C9 is connected to the end of the resistor R7 that is not connected to the resistor R6, and the other end is connected to the end of the resistor R8 that is not connected to the resistor R9.

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