Operational amplifier chip

Abstract

The present invention discloses an operational amplifier chip, and relates to the field of operational amplifiers. The chip comprises: a chip, a first input port, a second input port, a first metal wire, a second metal wire, and a metal frame of a single base island, wherein: the chip is mounted on the base island of the metal frame through adhesive, the metal frame is provided with a first input port and a second input port, the first input port and the second input port are connected through the metal frame, the first input port is connected to the first input pin of the chip through the first metal wire, and the second input port is connected to the second input pin of the chip through the second metal wire. The detection accuracy of the present invention can be met, and no complicated peripheral circuit is required, the occupied area is small, and different resistance values ​​can be achieved by changing the shape of the metal frame, thereby corresponding to different current detection ranges, and the manufacturing cost is low and the application is simple.

Description

Technical Field

[0001] The present invention relates to the field of operational amplifiers, and in particular to an operational amplifier chip, an operational amplifier and an electronic device comprising the operational amplifier. Background Art

[0002] In devices such as motors, electric machines, and inverters, a precision op amp and a well-matched precision resistor are usually used for current detection. Figure 1 As shown, this is a traditional current detection solution. Usually, a current sensing resistor is connected in parallel to the input end of the operational amplifier. The current value to be detected can be obtained by detecting the voltage of the current sensing resistor. Different current detection ranges can be achieved by adjusting the resistance value of the current sensing resistor.

[0003] However, when detecting large currents of tens of milliamperes, a current-sensing resistor with a small resistance, high precision and stable performance is required. However, the current-sensing resistor soldered on the PCB will introduce parasitic resistance, affecting its accuracy. Therefore, when it is actually used, it is necessary to calibrate the current-sensing resistor multiple times, which will greatly increase the cost. In addition, external current-sensing resistors are mostly plug-in or surface-mount components, which will occupy a large area. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an operational amplifier chip, an operational amplifier and an electronic device including the operational amplifier in view of the deficiencies in the prior art.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] An operational amplifier chip comprises: a chip, a first input port, a second input port, a first metal wire, a second metal wire and a metal frame of a single base island, wherein: the chip is mounted on the base island of the metal frame by means of a die adhesive, the metal frame is provided with the first input port and the second input port, the first input port and the second input port are connected via a current sensing resistor, the current sensing resistor is made of the metal frame, the first input port is connected to a first input pin of the chip via the first metal wire, and the second input port is connected to a second input pin of the chip via the second metal wire.

[0007] Another technical solution of the present invention to solve the above technical problems is as follows:

[0008] An operational amplifier chip comprises: a first chip, a second chip, a first input port, a second input port, a first metal wire, a second metal wire and a metal frame of a double base island, wherein:

[0009] The first chip is mounted on the first base island of the metal frame by means of adhesive, the metal frame is provided with the first input port and the second input port, the first input port and the second input port are connected via a current-sensing resistor, the current-sensing resistor is made of the metal frame, the first input port is connected to the first input pin of the first chip via the first metal wire, and the second input port is connected to the second input pin of the chip via the second metal wire;

[0010] The second chip is mounted on the second base island of the metal frame by means of adhesive, and the first chip and the second chip are connected by means of an isolation circuit.

[0011] Another technical solution of the present invention to solve the above technical problems is as follows:

[0012] An operational amplifier comprises the operational amplifier chip as described in any of the above technical solutions.

[0013] Another technical solution of the present invention to solve the above technical problems is as follows:

[0014] An electronic device comprises an operational amplifier as described in any of the above technical solutions.

[0015] The beneficial effects of the present invention are as follows: in the operational amplifier chip provided by the present invention, the current sensing resistor is composed of a metal frame between the first input port and the second input port. By integrating an external current sensing resistor inside the chip and calibrating the current sensing resistor, the operational amplifier chip can be directly connected in series in the current loop to be measured when in use, without the need for recalibration, the detection accuracy can be met, and no complex peripheral circuit is required, the occupied area is small, and different resistance values ​​can be achieved by changing the shape of the metal frame, thereby corresponding to different current detection ranges, and has the advantages of low manufacturing cost and simple application.

[0016] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a traditional current detection circuit;

[0018] Figure 2 A schematic structural diagram of the first embodiment of the operational amplifier chip of the present invention;

[0019] Figure 3 A schematic diagram of a circuit connection relationship provided for the first embodiment of the operational amplifier chip of the present invention;

[0020] Figure 4Another schematic diagram of circuit connection relationship provided for the first embodiment of the operational amplifier chip of the present invention;

[0021] Figure 5 A structural schematic diagram provided for the second embodiment of the operational amplifier chip of the present invention;

[0022] Figure 6 Another structural schematic diagram provided for the second embodiment of the operational amplifier chip of the present invention;

[0023] Figure 7 A schematic diagram of a circuit connection relationship provided for the second embodiment of the operational amplifier chip of the present invention;

[0024] Figure 8 Another schematic diagram of circuit connection relationship provided for the second embodiment of the operational amplifier chip of the present invention;

[0025] Fig. 9 Another structural schematic diagram provided for the second embodiment of the operational amplifier chip of the present invention. DETAILED DESCRIPTION

[0026] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention but not to limit the scope of the present invention.

[0027] It should be noted that operational amplifier chips are divided into isolated and non-isolated types. Isolated operational amplifiers are usually made of a metal frame with double base islands, and the two chips are connected by an isolation circuit. Non-isolated operational amplifiers are usually made of a metal frame with a single base island. These two situations are described below with examples.

[0028] Embodiment 1

[0029] like Figure 2 As shown, it is a structural schematic diagram provided by Embodiment 1 of the operational amplifier chip of the present invention. The operational amplifier chip is a non-isolated operational amplifier, which is made of a metal frame with a single base island, and includes: a chip 2, a first input port VIN+, a second input port VIN-, a first metal wire, a second metal wire and a metal frame 1, wherein: the chip 2 is mounted on the base island of the metal frame 1 by means of a die bonding adhesive, the metal frame 1 is provided with a first input port VIN+ and a second input port VIN-, the first input port VIN+ and the second input port VIN- are connected through a current sensing resistor 3, the current sensing resistor 3 is made of the metal frame 1, the first input port VIN+ is connected to the first input pin of the chip 2 through the first metal wire, and the second input port VIN- is connected to the second input pin of the chip 2 through the second metal wire.

[0030] The base island is provided with 8 ports in total. In addition to the first input port VIN+ and the second input port VIN-, there are 2 reserved ports on the same side, and the working voltage terminal VDD, the first output port VOUT+, the second output port VOUT- and the ground terminal GND are arranged on the other side.

[0031] like Figure 2 As shown, the chip 2 is mounted on the base island of the metal frame by means of adhesive, and the metal frame 1 between the first input port VIN+ and the second input port VIN- can be used as a current sensing resistor 3. In the conventional process of manufacturing an operational amplifier chip, the following is not retained: Figure 2 The metal frame 1 shown as the current-sensing resistor 3, that is, there is no metal frame 1 connecting the two ports between the first input port VIN+ and the second input port VIN-, and the operational amplifier chip of the present application can retain the metal frame 1 between the first input port VIN+ and the second input port VIN- during preparation, for example, it can be a metal sheet or a metal block, as the current-sensing resistor 3.

[0032] It should be understood that, according to actual needs, different shapes of metal frames 1 can be retained between the first input port VIN+ and the second input port VIN- to achieve different resistance values ​​of the current sensing resistor 3, thereby corresponding to different current detection ranges, and different numbers of input ports can also be selected.

[0033] In the operational amplifier chip provided in this embodiment, the current sensing resistor 3 is composed of a metal frame 1 between the first input port VIN+ and the second input port VIN-. By integrating the external current sensing resistor 3 into the chip 2 and calibrating the current sensing resistor 3, the operational amplifier chip can be directly connected in series in the current loop to be measured when in use, without the need for recalibration, the detection accuracy can be met, and no complex peripheral circuit is required, the occupied area is small, and different resistance values ​​can be achieved by changing the shape of the metal frame 1, thereby corresponding to different current detection ranges, and has the advantages of low manufacturing cost and simple application.

[0034] Optionally, in some possible implementations, such as Figure 3 As shown, the chip 2 includes: a first sampling resistor R1, a second sampling resistor R2, a first feedback resistor R3, a second feedback resistor R4 and an operational amplifier D, wherein:

[0035] The first input pin of the chip 2 is connected to the non-inverting input terminal of the operational amplifier D through the first sampling resistor R1, and the non-inverting input terminal of the operational amplifier D is also connected to the first output pin of the chip 2 through the first feedback resistor R3;

[0036] The second input pin of the chip 2 is connected to the inverting input terminal of the operational amplifier D through the second sampling resistor R2, and the inverting input terminal of the operational amplifier D is also connected to the second output pin of the chip 2 through the second feedback resistor R4;

[0037] The first output terminal of the operational amplifier D is connected to the first output pin of the chip 2 , and the second output terminal of the operational amplifier D is connected to the second output pin of the chip 2 .

[0038] It should be understood that Figure 3 The current sensing resistor 3 is formed by the metal frame 1 at the input end of the chip 2. Different resistance values ​​can be achieved by adjusting the different shapes of the metal frame 1, thereby corresponding to different current detection ranges.

[0039] The first sampling resistor R1, the second sampling resistor R2, the first feedback resistor R3, the second feedback resistor R4 and the operational amplifier D are used together to amplify the input signal. The first sampling resistor R1, the second sampling resistor R2, the first feedback resistor R3 and the second feedback resistor R4 can be composed of MOS resistors inside the operational amplifier chip, for example, they can be implemented by polycrystalline, metal or substrate, and the deviation of the amplification factor caused by the error of the current sensing resistor 3 can be compensated by adjusting the first feedback resistor R3 and the second feedback resistor R4.

[0040] Optionally, in some possible implementations, such as Figure 3 As shown, the chip 2 further includes: a first control circuit, a second control circuit, a first trimming circuit and a second trimming circuit, wherein:

[0041] The first control circuit is connected to the first trimming circuit, and the first trimming circuit is connected in parallel with the first feedback resistor R3;

[0042] The second control circuit is connected to the second trimming circuit, and the second trimming circuit is connected in parallel to the second feedback resistor R4.

[0043] The trimming circuit is used to correct the deviation of the resistance value of the current sensing resistor 3 caused by the process, and the control circuit is used to control the trimming circuit.

[0044] For example, the adjustment circuit may include multiple controllable switch tubes and multiple resistors. The control end of the controllable switch tube is connected to the output end of the control circuit as a signal input end. The controllable switch tube is controlled according to the signal received by the control end and the overall resistance value of the multiple resistors is determined. The two output ends of the adjustment circuit are connected in parallel with the feedback resistor, thereby correcting the resistance deviation of the current sensing resistor 3.

[0045] It should be understood that the control circuit may include a plurality of fuses, and the input terminal serves as a signal control terminal, and controls whether each of the plurality of fuses is blown by the input signal, thereby controlling the output state of the output terminal.

[0046] It should be noted that the structures of the adjustment circuit and the control circuit can also be implemented by other existing circuits, which will not be described in detail here.

[0047] Optionally, in some possible implementations, such as Figure 4 As shown, the chip 2 also includes: a modulation circuit, the first output end of the operational amplifier D is connected to the first output pin of the chip 2 through the modulation circuit, and the second output end of the operational amplifier D is connected to the second output pin of the chip 2 through the modulation circuit.

[0048] The modulation circuit is used to convert the output signal after passing through the operational amplifier D into a high-frequency modulated pulse signal.

[0049] When the modulation circuit is not included, the output end of the operational amplifier chip can be connected to the ADC circuit, and when the modulation circuit is included, the output end of the operational amplifier chip can be connected to the digital filter circuit.

[0050] It should be noted that the structure of the modulation circuit can be implemented by using an existing modulation circuit, for example, it can be implemented by using a ΔΣ modulation circuit, which will not be described in detail here.

[0051] It can be understood that in some embodiments, part or all of the above-mentioned embodiments may be included.

[0052] Embodiment 2

[0053] like Figure 5 FIG. 1 is a schematic diagram of a structure of a second embodiment of an operational amplifier chip of the present invention. The operational amplifier chip is an isolated operational amplifier, which is made of a double base island. The two chips are connected by an isolation circuit, including: a first chip 2, a second chip 4, a first input port VIN+, a second input port VIN-, a first metal wire, a second metal wire and a metal frame 1 of the double base island, wherein:

[0054] The first chip 2 is mounted on the first base island of the metal frame 1 by means of adhesive, the metal frame 1 is provided with a first input port VIN+ and a second input port VIN-, the first input port VIN+ and the second input port VIN- are connected by a current-sensing resistor 3, the current-sensing resistor 3 is made of the metal frame 1, the first input port VIN+ is connected to the first input pin of the first chip 2 by means of a first metal wire, and the second input port VIN- is connected to the second input pin of the chip by means of a second metal wire;

[0055] The second chip 4 is mounted on the second base island of the metal frame 1 by means of adhesive, and the first chip 2 and the second chip 4 are connected by means of an isolation circuit.

[0056] There are 8 ports in total on the two base islands. In addition to the first input port VIN+ and the second input port VIN-, a first working voltage terminal VDD1 and a first ground terminal GND1 are also arranged on the input side of the first base island, and a second working voltage terminal VDD2, a first output port VOUT+, a second output port VOUT- and a second ground terminal GND2 are arranged on the output side of the second base island.

[0057] like Figure 5 As shown, the first chip 2 and the second chip 4 are mounted on two base islands of the metal frame 1 by means of adhesive, and the metal frame between the first input port VIN+ and the second input port VIN- can be used as a current sensing resistor 3. In the conventional process of manufacturing an operational amplifier chip, the following is not retained: Figure 5 The metal frame shown as the current-sensing resistor 3, that is, there is no metal frame connecting the two ports between the first input port VIN+ and the second input port VIN-, and the operational amplifier chip of the present application can retain the metal frame between the first input port VIN+ and the second input port VIN- during preparation, for example, it can be a metal sheet or a metal block, as the current-sensing resistor 3.

[0058] The first chip 2 and the second chip 4 may be connected via an isolation circuit.

[0059] It should be understood that, according to actual needs, different shapes of metal frames 1 between the first input port VIN+ and the second input port VIN- can be selected to achieve different resistance values ​​of the current sensing resistor 3, thereby corresponding to different current detection ranges, and different numbers of input ports can also be selected.

[0060] For example, Figure 6 As shown, another shape of the current sensing resistor 3 is provided.

[0061] For example, Fig. 9 As shown, six ports are provided on the input side of the first chip 2, and two additional input ports are added.

[0062] In the operational amplifier chip provided in this embodiment, the current sensing resistor 3 is composed of a metal frame 1 between the first input port VIN+ and the second input port VIN-. By integrating the external current sensing resistor 3 inside the chip and calibrating the current sensing resistor 3, the operational amplifier chip can be directly connected in series in the current loop to be measured when in use, without the need for recalibration, the detection accuracy can be met, and no complex peripheral circuit is required, the occupied area is small, and different resistance values ​​can be achieved by changing the shape of the metal frame 1, thereby corresponding to different current detection ranges, which has the advantages of low manufacturing cost and simple application.

[0063] Optionally, in some possible implementations, such as Figure 7As shown, the first chip 2 includes: a first sampling resistor R1, a second sampling resistor R2, a first feedback resistor R3, a second feedback resistor R4 and an operational amplifier D, wherein:

[0064] The first input pin of the first chip 2 is connected to the non-inverting input terminal of the operational amplifier D through the first sampling resistor R1, and the non-inverting input terminal of the operational amplifier D is also connected to the first output pin of the first chip 2 through the first feedback resistor R3;

[0065] The second input pin of the first chip 2 is connected to the inverting input terminal of the operational amplifier D through the second sampling resistor R2, and the inverting input terminal of the operational amplifier D is also connected to the second output pin of the first chip 2 through the second feedback resistor R4;

[0066] The first output terminal and the second output terminal of the operational amplifier D are respectively connected to the isolation circuit.

[0067] It should be understood that Figure 7 The current sensing resistor 3 is composed of a metal frame at the input end of the chip. Different resistance values ​​can be achieved by adjusting the different shapes of the metal frame, thereby corresponding to different current detection ranges.

[0068] The first sampling resistor R1, the second sampling resistor R2, the first feedback resistor R3, the second feedback resistor R4 and the operational amplifier D are used together to amplify the input signal. The first sampling resistor R1, the second sampling resistor R2, the first feedback resistor R3 and the second feedback resistor R4 can be composed of MOS resistors inside the operational amplifier chip, for example, they can be implemented by polycrystalline, metal or substrate, and the deviation of the amplification factor caused by the error of the current sensing resistor 3 can be compensated by adjusting the first feedback resistor R3 and the second feedback resistor R4.

[0069] Optionally, in some possible implementations, such as Figure 7 As shown, the first chip 2 further includes: a first control circuit, a second control circuit, a first trimming circuit and a second trimming circuit, wherein:

[0070] The first control circuit is connected to the first trimming circuit, and the first trimming circuit is connected in parallel with the first feedback resistor R3;

[0071] The second control circuit is connected to the second trimming circuit, and the second trimming circuit is connected in parallel to the second feedback resistor R4.

[0072] The trimming circuit is used to correct the deviation of the resistance value of the current sensing resistor 3 caused by the process, and the control circuit is used to control the trimming circuit.

[0073] For example, the adjustment circuit may include multiple controllable switch tubes and multiple resistors. The control end of the controllable switch tube is connected to the output end of the control circuit as a signal input end. The controllable switch tube is controlled according to the signal received by the control end and the overall resistance value of the multiple resistors is determined. The two output ends of the adjustment circuit are connected in parallel with the feedback resistor, thereby correcting the resistance deviation of the current sensing resistor 3.

[0074] It should be understood that the control circuit may include a plurality of fuses, and the input terminal serves as a signal control terminal, and controls whether each of the plurality of fuses is blown by the input signal, thereby controlling the output state of the output terminal.

[0075] It should be noted that the structures of the adjustment circuit and the control circuit can also be implemented by other existing circuits, which will not be described in detail here.

[0076] Optionally, in some possible implementations, such as Figure 7 As shown, the first chip 2 further includes: a modulation circuit, a first output end of the operational amplifier D is connected to the isolation circuit through the modulation circuit, and a second output end of the operational amplifier D is connected to the isolation circuit through the modulation circuit.

[0077] The modulation circuit is used to convert the output signal after passing through the operational amplifier D into a high-frequency modulated pulse signal.

[0078] It should be noted that the structure of the modulation circuit can be implemented by using an existing modulation circuit, for example, it can be implemented by using a ΔΣ modulation circuit, which will not be described in detail here.

[0079] Optionally, in some possible implementations, such as Figure 8 As shown, the second chip 4 includes: a demodulation circuit, and the demodulation circuit is connected to the isolation circuit.

[0080] When the demodulation circuit is not included, the output end of the operational amplifier chip can be connected to the digital filtering circuit, and when the demodulation circuit is included, the output end of the operational amplifier chip can be connected to the ADC circuit.

[0081] It should be noted that the isolation circuit can be implemented by a transformer or a capacitor. The transformer or capacitor can be set on the first chip 2, or on the second chip 4 according to actual needs, or can be set on the first chip 2 and the second chip 4 respectively. For example, taking the capacitor as an example, one plate of the capacitor can be set on the first chip 2, and the other plate of the capacitor can be set on the second chip 4, so as to realize the isolated transmission of high-frequency pulse signals.

[0082] It should be understood that when the demodulation circuit is not included, an isolation circuit may be separately provided on the second chip 4 , or a part of the isolation circuit may be provided.

[0083] For example, the modulation circuit can be implemented by a ΔΣ modulation circuit, and the demodulation circuit can be implemented by a filter circuit.

[0084] It can be understood that in some embodiments, part or all of the above-mentioned embodiments may be included.

[0085] Embodiment 3

[0086] The present invention also provides an operational amplifier, comprising the operational amplifier chip disclosed in any of the above embodiments.

[0087] Embodiment 4

[0088] The present invention also provides an electronic device, comprising the operational amplifier disclosed in any of the above embodiments.

[0089] It should be understood that the electronic device is a device that requires or includes an operational amplifier, such as a motor, an electric machine, or an inverter.

[0090] The reader should understand that, in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "embodiments one / two / three / four", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples and the features of the different embodiments or examples described in this specification without contradiction.

[0091] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An operational amplifier chip, characterized in that: include: A chip, a first input port, a second input port, a first metal wire, a second metal wire and a metal frame of a single base island, wherein: the chip is mounted on the base island of the metal frame by means of adhesive, the metal frame is provided with the first input port and the second input port, the first input port and the second input port are connected via a current-sensing resistor, the current-sensing resistor is made of the metal frame, the first input port is connected to the first input pin of the chip via the first metal wire, and the second input port is connected to the second input pin of the chip via the second metal wire.

2. The operational amplifier chip according to claim 1, characterized in that: The chip comprises: a first sampling resistor, a second sampling resistor, a first feedback resistor, a second feedback resistor and an operational amplifier, wherein: The first input pin of the chip is connected to the non-inverting input terminal of the operational amplifier through the first sampling resistor, and the non-inverting input terminal of the operational amplifier is also connected to the first output pin of the chip through the first feedback resistor; The second input pin of the chip is connected to the inverting input terminal of the operational amplifier through the second sampling resistor, and the inverting input terminal of the operational amplifier is also connected to the second output pin of the chip through the second feedback resistor; The first output end of the operational amplifier is connected to the first output pin of the chip, and the second output end of the operational amplifier is connected to the second output pin of the chip.

3. The operational amplifier chip according to claim 2, characterized in that: The chip further includes: a first control circuit, a second control circuit, a first trimming circuit and a second trimming circuit, wherein: The first control circuit is connected to the first trimming circuit, and the first trimming circuit is connected in parallel with the first feedback resistor; The second control circuit is connected to the second trimming circuit, and the second trimming circuit is connected in parallel to the second feedback resistor.

4. The operational amplifier chip according to claim 2 or 3, characterized in that: The chip further includes: a modulation circuit, through which the first output end of the operational amplifier is connected to the first output pin of the chip, and the second output end of the operational amplifier is connected to the second output pin of the chip.

5. An operational amplifier chip, characterized in that: include: A first chip, a second chip, a first input port, a second input port, a first metal line, a second metal line, and a metal frame of a double base island, wherein: The first chip is mounted on the first base island of the metal frame by means of adhesive, the metal frame is provided with the first input port and the second input port, the first input port and the second input port are connected via a current-sensing resistor, the current-sensing resistor is made of the metal frame, the first input port is connected to the first input pin of the first chip via the first metal wire, and the second input port is connected to the second input pin of the chip via the second metal wire; The second chip is mounted on the second base island of the metal frame by means of adhesive, and the first chip and the second chip are connected by means of an isolation circuit.

6. The operational amplifier chip according to claim 5, characterized in that: The first chip includes: a first sampling resistor, a second sampling resistor, a first feedback resistor, a second feedback resistor and an operational amplifier, wherein: The first input pin of the first chip is connected to the non-inverting input terminal of the operational amplifier through the first sampling resistor, and the non-inverting input terminal of the operational amplifier is also connected to the first output pin of the first chip through the first feedback resistor; The second input pin of the first chip is connected to the inverting input terminal of the operational amplifier through the second sampling resistor, and the inverting input terminal of the operational amplifier is also connected to the second output pin of the first chip through the second feedback resistor; The first output terminal and the second output terminal of the operational amplifier are respectively connected to the isolation circuit.

7. The operational amplifier chip according to claim 6, characterized in that: The first chip further includes: a first control circuit, a second control circuit, a first trimming circuit, and a second trimming circuit, wherein: The first control circuit is connected to the first trimming circuit, and the first trimming circuit is connected in parallel with the first feedback resistor; The second control circuit is connected to the second trimming circuit, and the second trimming circuit is connected in parallel to the second feedback resistor.

8. The operational amplifier chip according to claim 6 or 7, characterized in that: The first chip further includes: a modulation circuit, through which the first output end of the operational amplifier is connected to the isolation circuit, and through which the second output end of the operational amplifier is connected to the isolation circuit.

9. The operational amplifier chip according to claim 5, characterized in that: The second chip includes: a demodulation circuit, and the demodulation circuit is connected to the isolation circuit.

10. An operational amplifier, characterized in that: The operational amplifier chip comprises the operational amplifier chip as claimed in any one of claims 1 to 4, or comprises the operational amplifier chip as claimed in any one of claims 5 to 9.

11. An electronic device, characterized in that: Comprising the operational amplifier as claimed in claim 10.

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