A self-calibrating operational amplifier circuit

Abstract

The present invention discloses a self-calibration operational amplifier circuit, which is characterized by comprising a main operational amplifier, an electrostatic discharge circuit and a leakage calibration circuit, wherein the inverting end of the main operational amplifier is electrically connected to the electrostatic discharge circuit, the leakage calibration circuit comprises a calibration compensation circuit, an energy storage element and a calibration switch group, the energy storage element is used to store the leakage compensation voltage, the calibration switch group is used to change the working state of the calibration compensation circuit, and the calibration compensation circuit is electrically connected to the main operational amplifier, the energy storage element and the electrostatic discharge circuit through the calibration switch group; the advantage is that since the main operational amplifier is connected to the leakage calibration circuit, the main operational amplifier is leakage calibrated and leakage calibration compensated through the leakage calibration circuit, so that the leakage current of the electrostatic discharge circuit connected to the main operational amplifier reaches at least the fA level, thereby effectively realizing self-calibration, ensuring that the working leakage current of the main operational amplifier can always meet the requirements of the working scenario, and improving the stability and reliability of the work.

Description

Technical Field

[0001] The present invention relates to an operational amplifier circuit, and in particular to an operational amplifier circuit with a self-calibration function. Background Art

[0002] Currently, due to the requirements of operational applications, the device pins of chips such as operational amplifiers are only allowed to have extremely low leakage currents during operation, generally in the femtoampere range. However, due to the extremely low leakage current at the input pins of operational amplifiers, it is currently impossible to ensure that the leakage current can always reach the femtoampere level during operation. Therefore, how to ensure the stability and reliability of operational amplifiers is an urgent problem that needs to be solved. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a self-calibrating operational amplifier circuit, which can effectively realize the self-calibration of the operational amplifier, ensure that the operating leakage current of the main operational amplifier can always reach at least the femtoampere level, and can always meet the needs of the working scenario, thereby ensuring the stability and reliability of the operation of the main operational amplifier.

[0004] The technical solution adopted by the present invention to solve the above technical problems is: a self-calibration operational amplifier circuit, including a main operational amplifier, an electrostatic discharge circuit and a leakage calibration circuit, the inverting terminal of the main operational amplifier is electrically connected to the electrostatic discharge circuit, the leakage calibration circuit includes a calibration compensation circuit, an energy storage element and a calibration switch group, the energy storage element is used to store the leakage compensation voltage, the calibration switch group is used to change the working state of the calibration compensation circuit, and the calibration compensation circuit is electrically connected to the main operational amplifier, the energy storage element and the electrostatic discharge circuit through the calibration switch group;

[0005] When leakage calibration is performed on the main operational amplifier, the calibration compensation circuit obtains a leakage compensation voltage between the non-inverting terminal and the inverting terminal of the main operational amplifier, and stores the obtained leakage compensation voltage in the energy storage element;

[0006] When leakage calibration compensation is performed on the main operational amplifier, the leakage compensation voltage stored in the energy storage element is loaded into the electrostatic discharge circuit through the calibration compensation circuit, so that the leakage current of the electrostatic discharge circuit reaches at least the fA level.

[0007] Furthermore, the calibration compensation circuit includes an auxiliary operational amplifier and a main buffer:

[0008] When leakage calibration is performed on the main operational amplifier, the non-inverting terminal of the auxiliary operational amplifier, the non-inverting terminal of the main operational amplifier, and the first end of the energy storage element are electrically connected, the inverting terminal of the auxiliary operational amplifier, the output terminal of the main operational amplifier, and one end of the integrating capacitor are electrically connected, the other end of the integrating capacitor is electrically connected to the inverting terminal of the main operational amplifier, the output terminal of the auxiliary operational amplifier, the second end of the energy storage element, and the input terminal of the main buffer are electrically connected, and the output terminal of the main buffer is electrically connected to the electrostatic discharge circuit;

[0009] When leakage calibration compensation is performed on the main operational amplifier, the first end of the energy storage element is electrically connected to the non-inverting end of the main operational amplifier, the second end of the energy storage element is electrically connected to the input end of the main buffer, and the output end of the main buffer is electrically connected to the electrostatic discharge circuit.

[0010] Furthermore, the calibration switch group includes a first calibration switch, a second calibration switch, a third calibration switch, a fourth calibration switch, a fifth calibration switch, a sixth calibration switch, and a seventh calibration switch. One end of the first calibration switch is electrically connected to the non-inverting terminal of the main operational amplifier and the first end of the energy storage element. The other end of the first calibration switch is electrically connected to the non-inverting terminal of the auxiliary operational amplifier. One end of the second calibration switch is electrically connected to the output terminal of the auxiliary operational amplifier. The other end of the second calibration switch is electrically connected to the second end of the energy storage element and the input terminal of the main buffer. One end of the third calibration switch is electrically connected to the inverting terminal of the auxiliary operational amplifier. The other end of the third calibration switch is electrically connected to the output terminal of the main operational amplifier, one end of the fifth calibration switch, and one end of the fourth calibration switch. The other end of the fourth calibration switch is electrically connected to the output terminal of the main operational amplifier. The other end of the fifth calibration switch is electrically connected to one end of the integrating capacitor and one end of the sixth calibration switch. The other end of the sixth calibration switch and the other end of the integrating capacitor are both electrically connected to the inverting terminal of the main operational amplifier. The seventh calibration switch is connected in parallel with the energy storage element.

[0011] Furthermore, the energy storage element is an energy storage capacitor, and the seventh calibration switch is connected in parallel with the energy storage capacitor.

[0012] Furthermore, the main operational amplifier is provided with a main state control terminal, which receives a main state control signal:

[0013] When the main state control signal is at a high level, the first calibration switch, the second calibration switch and the fifth calibration switch are controlled to be in a closed state, and the fourth calibration switch, the sixth calibration switch and the seventh calibration switch are controlled to be in an open state;

[0014] When the main state control signal is at a low level, the first calibration switch, the second calibration switch, the third calibration switch, and the fifth calibration switch are controlled to be in a closed state, and the fourth calibration switch, the sixth calibration switch, and the seventh calibration switch are controlled to be in an open state, so as to perform leakage calibration on the main operational amplifier. After the leakage calibration of the main operational amplifier, the fourth calibration switch and the sixth calibration switch are controlled to be in a closed state, and the first calibration switch, the second calibration switch, the third calibration switch, the fifth calibration switch, and the seventh calibration switch are controlled to be in an open state, so as to perform leakage calibration compensation on the main operational amplifier.

[0015] Furthermore, the main buffer is an operational amplifier, the output terminal and the inverting terminal of the operational amplifier are both electrically connected to the electrostatic discharge circuit, and the non-inverting terminal of the operational amplifier serves as the input terminal of the main buffer.

[0016] Furthermore, the electrostatic discharge circuit includes a first diode and a second diode, the cathode end of the first diode and the anode end of the second diode are both electrically connected to the inverting end of the main operational amplifier, and the anode end of the first diode and the cathode end of the second diode are both electrically connected to the output end of the main buffer.

[0017] Furthermore, the auxiliary operational amplifier includes an input protection module, an NCH input stage amplifier, a slew rate improvement module, a PCH input stage amplifier, a high capacitive load compensation module and an output stage circuit. The NCH input stage amplifier, the slew rate improvement module and the PCH input stage amplifier are all electrically connected to the input protection module, the NCH input stage amplifier and the PCH input stage amplifier are both electrically connected to the high capacitive load compensation module, and the high capacitive load compensation module is electrically connected to the output stage circuit.

[0018] Compared with the prior art, the advantage of the present invention is that since a leakage calibration circuit is connected to the main operational amplifier, leakage calibration and leakage calibration compensation are performed on the main operational amplifier through the leakage calibration circuit, so that the leakage current of the electrostatic discharge circuit connected to the main operational amplifier reaches at least the fA level, effectively realizing self-calibration, ensuring that the working leakage current of the main operational amplifier can always meet the requirements of the working scenario, and improving the stability and reliability of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a circuit principle diagram of the present invention;

[0020] Figure 2 A circuit diagram of the present invention entering a leakage calibration working state;

[0021] Figure 3 A circuit diagram of the present invention entering a leakage calibration and compensation working state;

[0022] Figure 4 A circuit diagram of the present invention entering a non-calibration working state;

[0023] Figure 5 This is a schematic diagram of the working state conversion of the present invention;

[0024] Figure 6 It is a timing diagram of the working state conversion of the present invention;

[0025] Figure 7 4 is a structural block diagram of the auxiliary operational amplifier of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0027] As shown in the figure, a self-calibration operational amplifier circuit includes a main operational amplifier U1, an electrostatic discharge circuit, and a leakage calibration circuit. The inverting terminal of the main operational amplifier U1 is electrically connected to the electrostatic discharge circuit. The electrostatic discharge circuit can provide a discharge channel for the leakage at the inverting terminal of the main operational amplifier U1. The leakage calibration circuit includes a calibration compensation circuit, an energy storage element, and a calibration switch group. The energy storage element is an energy storage capacitor C1, which is used to store the leakage compensation voltage. The calibration compensation circuit includes an auxiliary operational amplifier U3 and a main buffer. The calibration switch group is used to change the working state of the calibration compensation circuit to achieve different connection coordination between the auxiliary operational amplifier U3, the main buffer, the main operational amplifier U1, and the energy storage element, so as to achieve leakage calibration of the main operational amplifier U1 and leakage calibration compensation after leakage calibration.

[0028] When the main operational amplifier U1 is subjected to leakage calibration by the leakage calibration circuit, the non-inverting terminal of the auxiliary operational amplifier U3, the non-inverting terminal of the main operational amplifier U1, and the first end of the energy storage capacitor C1 are electrically connected, the inverting terminal of the auxiliary operational amplifier U3, the output terminal of the main operational amplifier U1, and one end of the integrating capacitor C2 are electrically connected, the other end of the integrating capacitor C2 is electrically connected to the inverting terminal of the main operational amplifier U1, the output terminal of the auxiliary operational amplifier U3, the second end of the energy storage capacitor C1, and the input terminal of the main buffer are electrically connected, and the output terminal of the main buffer is electrically connected to the electrostatic discharge circuit; the calibration compensation circuit obtains a leakage compensation voltage between the non-inverting terminal and the inverting terminal of the main operational amplifier U1, and stores the obtained leakage compensation voltage in the energy storage capacitor C1;

[0029] When leakage calibration compensation is performed on the main operational amplifier U1 through the leakage calibration circuit, the first end of the energy storage capacitor C1 is electrically connected to the non-inverting end of the main operational amplifier U1, the second end of the energy storage capacitor C1 is electrically connected to the input end of the main buffer, and the output end of the main buffer is electrically connected to the electrostatic discharge circuit. The leakage compensation voltage stored in the energy storage capacitor C1 is loaded into the electrostatic discharge circuit through the calibration compensation circuit, so that leakage compensation is performed using the leakage compensation voltage, so that the leakage in the electrostatic discharge circuit approaches 0, so that the leakage current of the electrostatic discharge circuit reaches at least the fA level.

[0030] The main operational amplifier U1 can be a commonly used design, selected as needed. However, the leakage current between the non-inverting and inverting terminals of the selected main operational amplifier U1 must meet the requirements of the femtoampere level. This means that when the main operational amplifier U1 is operating, the leakage current at the input of the main operational amplifier U1 is extremely low. The main buffer can be an existing operational amplifier U2, with both its output and inverting terminals electrically connected to the electrostatic discharge circuit. The non-inverting terminal of the operational amplifier U2 serves as the input of the main buffer, thus enabling the operational amplifier to function as a voltage follower.

[0031] like Figure 1As shown, the electrostatic discharge circuit includes a first diode D1 and a second diode D2, the cathode terminal of the first diode D1 and the anode terminal of the second diode D2 are both electrically connected to the inverting terminal of the main operational amplifier U1, and the anode terminal of the first diode D1 and the cathode terminal of the second diode D2 are both electrically connected to the output terminal of the main buffer, and the calibration switch group includes a first calibration switch S1, a second calibration switch S2, a third calibration switch S3, a fourth calibration switch S4, a fifth calibration switch S5, a sixth calibration switch S6 and a seventh calibration switch S7, one end of the first calibration switch S1 is electrically connected to the non-inverting terminal of the main operational amplifier U1 and the first end of the energy storage capacitor C1, the other end of the first calibration switch S1 is electrically connected to the non-inverting terminal of the auxiliary operational amplifier U3, one end of the second calibration switch S2 is electrically connected to the output terminal of the auxiliary operational amplifier U3, and the other end of the second calibration switch S2 is electrically connected to the second end of the energy storage capacitor C1, The input terminal of the main buffer is electrically connected, one end of the third calibration switch S3 is electrically connected to the inverting terminal of the auxiliary operational amplifier U3, the other end of the third calibration switch S3 is electrically connected to the output terminal of the main operational amplifier U1, one end of the fifth calibration switch S5, and one end of the fourth calibration switch S4, the other end of the fourth calibration switch S4 is electrically connected to the main operational amplifier output terminal OUT, the other end of the fifth calibration switch S5 is electrically connected to one end of the integrating capacitor C2 and one end of the sixth calibration switch S6, the other end of the sixth calibration switch S6 and the other end of the integrating capacitor C2 are both electrically connected to the inverting terminal of the main operational amplifier U1, the seventh calibration switch S7 is connected in parallel with the energy storage capacitor C1, and the sixth calibration switch S6 is connected in parallel with the integrating capacitor C2. The sixth calibration switch S6 can always provide a discharge circuit for the integrating capacitor C2, ensuring that the charge on the integrating capacitor C2 is uniform when the circuit is started, thereby ensuring the reliability of the entire circuit during operation. In addition, the first calibration switch S1 , the second calibration switch S2 , the third calibration switch S3 , the fourth calibration switch S4 , the fifth calibration switch S5 , the sixth calibration switch S6 and the seventh calibration switch S7 may all be conventional controllable switches, such as MOSFET devices.

[0032] Preferably, in order to effectively configure the working state of the entire operational amplifier circuit, a main state control terminal is provided on the main operational amplifier U1, and the main state control terminal receives the main state control signal EN, so that the working state of the entire operational amplifier circuit can be configured according to the main state control signal EN, such as Figure 5 FIG. 1 is a schematic diagram showing how the working state of the entire operational amplifier circuit is switched according to the main state control signal EN in the present invention. Figure 6 The specific switch control timing diagram for the main state control signal EN and the calibration switch group is as follows:

[0033] When the main state control signal EN is at a high level, the first calibration switch S1, the second calibration switch S2 and the fifth calibration switch S5 are controlled to be in a closed state, and the fourth calibration switch S4, the sixth calibration switch S6 and the seventh calibration switch S7 are controlled to be in an open state;

[0034] When the main state control signal EN is at a low level, the first calibration switch S1, the second calibration switch S2, the third calibration switch S3, and the fifth calibration switch S5 are controlled to be in a closed state, while the fourth calibration switch S4, the sixth calibration switch S6, and the seventh calibration switch S7 are controlled to be in an open state, so as to perform leakage calibration on the main operational amplifier U1. After the leakage calibration of the main operational amplifier U1, the fourth calibration switch S4 and the sixth calibration switch S6 are controlled to be in a closed state, while the first calibration switch S1, the second calibration switch S2, the third calibration switch S3, the fifth calibration switch S5, and the seventh calibration switch S7 are controlled to be in an open state, so as to perform leakage calibration compensation on the main operational amplifier U1.

[0035] Figure 2 This is a schematic diagram of the entire operational amplifier circuit during leakage calibration. At this point, the first diode D1 and the second diode D2 provide an electrostatic discharge channel for leakage at the inverting terminal of the main operational amplifier U1. The voltage difference between the first diode D1 and the second diode D2 is also the voltage difference between the inverting terminal of the main operational amplifier U1 and the output terminal of the main buffer U2. When the voltage difference between the first diode D1 and the second diode D2 is not zero, varying degrees of leakage will occur in the first diode D1 and the second diode D2. During leakage calibration, the auxiliary operational amplifier U3 and the integrating capacitor C2 work together with the main operational amplifier U1. When the output of the main operational amplifier U1 is stable, the capacitor voltage of the integrating capacitor C2 remains unchanged, resulting in no leakage current at the inverting terminal of the main operational amplifier U1. At this point, the voltage difference between the output terminal of the auxiliary operational amplifier U3 and its non-inverting terminal is the leakage voltage that needs to be compensated by the main buffer U2. The leakage compensation voltage is stored in the energy storage capacitor C1 via the output of the auxiliary operational amplifier U3.

[0036] Figure 3 Figure 2 is a schematic diagram of the leakage calibration and compensation working state after leakage calibration. At this time, the leakage compensation voltage in the energy storage capacitor C1 is loaded onto the anode terminal of the first diode D1 and the cathode terminal of the second diode D2 via the main buffer U2. According to the above-mentioned process of determining the leakage compensation voltage, after the leakage compensation voltage is loaded onto the electrostatic discharge circuit via the main buffer U2, the voltage difference between the first diode D1 and the second diode D2 can be made close to zero. Therefore, the leakage current at the inverting terminal of the main operational amplifier U1 approaches zero, which can meet the requirement that the leakage current at the inverting terminal of the main operational amplifier U1 is at least at the femtoampere level.

[0037] Of course, in specific implementation, by utilizing the connection of the seventh calibration switch S7 and the energy storage capacitor C1, the entire operational amplifier circuit can also be directly put into a non-calibration working state, such as Figure 4 As shown, at this point, the energy storage capacitor C1 is short-circuited via the seventh calibration switch S7, and the non-inverting terminal of the main operational amplifier U1 is directly connected to the input terminal of the main buffer U2. During operation, the voltage at the non-inverting terminal of the main operational amplifier U1 is applied to the electrostatic discharge circuit via the main buffer U2. The voltage difference between the first diode D1 and the second diode D2 is the voltage difference between the inverting and non-inverting terminals of the main operational amplifier U1. Due to the lack of leakage calibration, it is impossible to effectively ensure that the leakage current at the inverting terminal of the main operational amplifier U1 is in the femtoampere level or less.

[0038] In a specific implementation, in order to ensure that the leakage current at the inverting terminal of the main operational amplifier U1 is in the fA level or less, the entire circuit needs to be in a cycle of leakage calibration working state - leakage calibration compensation working state - leakage calibration working state - leakage calibration compensation working state. The cycle of the leakage calibration working state and the leakage calibration compensation working state can be set or adjusted by the energy storage capacity of the energy storage capacitor C1. The details are well known to those skilled in the art and will not be repeated here. Of course, since the main operational amplifier output terminal OUT of the entire operational amplifier circuit is in an idle state during the leakage calibration working state, the specific conditions of the leakage calibration working state shall be based on whether it matches the actual operating requirements of the main operational amplifier U1.

[0039] In addition, in this embodiment, the auxiliary operational amplifier U3 includes an input protection module 1, an NCH input stage amplifier 2, a slew rate improvement module 3, a PCH input stage amplifier 4, a high capacitive load compensation module 5 and an output stage circuit 6. The NCH input stage amplifier 2, the slew rate improvement module 3 and the PCH input stage amplifier 4 are all electrically connected to the input protection module 1, the NCH input stage amplifier 2 and the PCH input stage amplifier 4 are all electrically connected to the high capacitive load compensation module 5, and the high capacitive load compensation module 5 is electrically connected to the output stage circuit 6; the input protection module 1 can receive the voltages of the in-phase terminal and the inverting terminal of the auxiliary operational amplifier U3, and the input protection module 1 can protect the input voltage to avoid damage to the entire auxiliary operational amplifier U3 when the voltages of the in-phase terminal and the inverting terminal of the auxiliary operational amplifier U3 are too large; and in order to achieve auxiliary operational amplification with a wider voltage range, the NCH input stage amplifier 2 and the PCH input stage amplifier 4 are set in the auxiliary operational amplifier U3. If the voltage between the in-phase terminal and the inverting terminal of the auxiliary operational amplifier U3 is too large, the auxiliary operational amplifier U3 will be damaged. When the difference is close to 0, the leakage compensation voltage can be output through the PCH input stage amplifier 4, the high capacitive load compensation module 5 and the output stage circuit 6. When the voltage difference between the in-phase terminal and the inverting terminal of the auxiliary operational amplifier U3 is close to the maximum allowable voltage, the leakage compensation voltage can be output through the NCH input stage amplifier 2, the high capacitive load compensation module 5 and the output stage circuit 6. The response speed of the NCH input stage amplifier 2 or the PCH input stage amplifier 4 during operation can be improved by the slew rate improvement module 3, high capacitive load compensation can be achieved by the high capacitive load compensation module 5, and the circuit stability can be improved. The output capacity of the entire auxiliary operational amplifier U3 can be improved by the output stage circuit 6.

[0040] The input protection module 1, NCH input stage amplifier 2, slew rate boost module 3, PCH input stage amplifier 4, high capacitive load compensation module 5 and output stage circuit 6 in the auxiliary operational amplifier U3 can all adopt existing commonly used modules.

[0041] The protection scope of the present invention includes but is not limited to the above embodiments, and its protection scope is subject to the claims. Any replacement, deformation, and improvement of this technology that can be easily thought of by those skilled in the art fall within the protection scope of the present invention.

Claims

1. A self-calibrating operational amplifier circuit, characterized in that The invention comprises a main operational amplifier (U1), an electrostatic discharge circuit and a leakage calibration circuit, wherein the inverting terminal of the main operational amplifier (U1) is electrically connected to the electrostatic discharge circuit, the leakage calibration circuit comprises a calibration compensation circuit, an energy storage element and a calibration switch group, the energy storage element is used to store the leakage compensation voltage, the calibration switch group is used to change the working state of the calibration compensation circuit, and the calibration compensation circuit is electrically connected to the main operational amplifier (U1), the energy storage element and the electrostatic discharge circuit via the calibration switch group; The calibration compensation circuit includes an auxiliary operational amplifier (U3) and a main buffer: When leakage calibration is performed on the main operational amplifier (U1), the calibration compensation circuit obtains a leakage compensation voltage between the non-inverting terminal and the inverting terminal of the main operational amplifier (U1), and stores the obtained leakage compensation voltage in the energy storage element; specifically, the non-inverting terminal of the auxiliary operational amplifier (U3), the non-inverting terminal of the main operational amplifier (U1), and the first end of the energy storage element are electrically connected; the inverting terminal of the auxiliary operational amplifier (U3), the output terminal of the main operational amplifier (U1), and one end of the integration capacitor (C2) are electrically connected; the other end of the integration capacitor (C2) is electrically connected to the inverting terminal of the main operational amplifier (U1); the output terminal of the auxiliary operational amplifier (U3), the second end of the energy storage element, and the input terminal of the main buffer are electrically connected; and the output terminal of the main buffer is electrically connected to the electrostatic discharge circuit; When leakage calibration compensation is performed on the main operational amplifier (U1), the leakage compensation voltage stored in the energy storage element is loaded onto the electrostatic discharge circuit through the calibration compensation circuit, so that the leakage current of the electrostatic discharge circuit reaches at least the fA level; specifically, the first end of the energy storage element is electrically connected to the in-phase end of the main operational amplifier (U1), the second end of the energy storage element is electrically connected to the input end of the main buffer, and the output end of the main buffer is electrically connected to the electrostatic discharge circuit.

2. The self-calibrating operational amplifier circuit according to claim 1, wherein: The calibration switch group includes a first calibration switch (S1), a second calibration switch (S2), a third calibration switch (S3), a fourth calibration switch (S4), a fifth calibration switch (S5), a sixth calibration switch (S6) and a seventh calibration switch (S7). One end of the first calibration switch (S1) is electrically connected to the in-phase end of the main operational amplifier (U1) and the first end of the energy storage element. The other end of the first calibration switch (S1) is electrically connected to the in-phase end of the auxiliary operational amplifier (U3). One end of the second calibration switch (S2) is electrically connected to the output end of the auxiliary operational amplifier (U3). The other end of the second calibration switch (S2) is electrically connected to the second end of the energy storage element and the input end of the main buffer. One end of the switch (S3) is electrically connected to the inverting end of the auxiliary operational amplifier (U3); the other end of the third calibration switch (S3) is electrically connected to the output end of the main operational amplifier (U1), one end of the fifth calibration switch (S5), and one end of the fourth calibration switch (S4); the other end of the fourth calibration switch (S4) is electrically connected to the main operational amplifier output end (OUT); the other end of the fifth calibration switch (S5) is electrically connected to one end of the integration capacitor (C2) and one end of the sixth calibration switch (S6); the other end of the sixth calibration switch (S6) and the other end of the integration capacitor (C2) are both electrically connected to the inverting end of the main operational amplifier (U1); and the seventh calibration switch (S7) is connected in parallel with the energy storage element.

3. The self-calibrating operational amplifier circuit according to claim 2, wherein: The energy storage element is an energy storage capacitor (C1), and the seventh calibration switch (S7) is connected in parallel with the energy storage capacitor (C1).

4. The self-calibrating operational amplifier circuit according to claim 2, wherein: The main operational amplifier (U1) is provided with a main state control terminal, through which a main state control signal (EN) is received: When the main state control signal (EN) is at a high level, the first calibration switch (S1), the second calibration switch (S2) and the fifth calibration switch (S5) are controlled to be in a closed state, and the fourth calibration switch (S4), the sixth calibration switch (S6) and the seventh calibration switch (S7) are controlled to be in an open state; When the main state control signal (EN) is at a low level, the first calibration switch (S1), the second calibration switch (S2), the third calibration switch (S3) and the fifth calibration switch (S5) are controlled to be in a closed state, and the fourth calibration switch (S4), the sixth calibration switch (S6) and the seventh calibration switch (S7) are controlled to be in an open state, so as to perform leakage calibration on the main operational amplifier (U1); after the leakage calibration of the main operational amplifier (U1), the fourth calibration switch (S4) and the sixth calibration switch (S6) are controlled to be in a closed state, and the first calibration switch (S1), the second calibration switch (S2), the third calibration switch (S3), the fifth calibration switch (S5) and the seventh calibration switch (S7) are controlled to be in an open state, so as to perform leakage calibration compensation on the main operational amplifier (U1).

5. The self-calibrating operational amplifier circuit according to claim 1, wherein: The main buffer is an operational amplifier (U2), the output end and the inverting end of the operational amplifier (U2) are both electrically connected to the electrostatic discharge circuit, and the non-inverting end of the operational amplifier (U2) serves as the input end of the main buffer.

6. The self-calibrating operational amplifier circuit according to claim 1, wherein: The electrostatic discharge circuit comprises a first diode (D1) and a second diode (D2), wherein the cathode end of the first diode (D1) and the anode end of the second diode (D2) are both electrically connected to the inverting end of the main operational amplifier (U1), and the anode end of the first diode (D1) and the cathode end of the second diode (D2) are both electrically connected to the output end of the main buffer.

7. The self-calibrating operational amplifier circuit according to claim 1, wherein: The auxiliary operational amplifier (U3) comprises an input protection module (1), an NCH input stage amplifier (2), a slew rate enhancement module (3), a PCH input stage amplifier (4), a high capacitive load compensation module (5) and an output stage circuit (6); the NCH input stage amplifier (2), the slew rate enhancement module (3) and the PCH input stage amplifier (4) are all electrically connected to the input protection module (1); the NCH input stage amplifier (2) and the PCH input stage amplifier (4) are all electrically connected to the high capacitive load compensation module (5); and the high capacitive load compensation module (5) is electrically connected to the output stage circuit (6).

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