Current detection circuit and electronic equipment

Abstract

The utility model discloses a current detection circuit and electronic equipment, and the circuit comprises an inductor which is disposed in a to-be-detected current loop; the first end of the first resistor is connected with the first end of the inductor; the first end of the first capacitor is connected with the second end of the first resistor, and the second end of the first capacitor is connected with the second end of the inductor; the differential signal processing module is connected with the first end and the second end of the first capacitor, and the differential signal processing module is configured to detect a first differential voltage signal between the first end and the second end of the first capacitor and convert the first differential voltage signal into a corresponding single-end voltage signal; the single-end voltage signal is used for determining the current flowing through the current loop to be detected. In this way, the current detection cost is reduced, and the product flexibility is improved.

Description

Technical Field

[0001] The present application relates to the field of electronic circuits, and in particular to a current detection circuit and an electronic device. Background Art

[0002] In today's daily life, high current application scenarios have put forward requirements for current detection of the line. The electronic system needs to collect the working current to achieve the purpose of detecting, diagnosing and protecting the system. At present, the proprietary current detection solutions on the market are mainly implemented by precision resistors and current detection chips. However, currents of tens of A or even hundreds of A require extremely small mΩ resistors, which require very small voltage drops across the precision resistors. Precision resistors withstand large power and require a large heat dissipation space. At the same time, the precision requirements for precision resistors are also relatively high, and the cost is relatively high. At the same time, precision resistors usually need to be connected in series between the power input and the load or between the load and the ground terminal, which limits the flexibility of the product. Utility Model Content

[0003] In order to solve the above problems, the present application provides a current detection circuit and an electronic device, which can detect the current of a line and can reduce technical costs and improve product flexibility.

[0004] A technical solution adopted in the present application is to provide a current detection circuit, which includes: an inductor, which is arranged in a current loop to be detected; a first resistor, wherein the first end of the first resistor is connected to the first end of the inductor; a first capacitor, wherein the first end of the first capacitor is connected to the second end of the first resistor, and the second end of the first capacitor is connected to the second end of the inductor; a differential signal processing module, which is connected to the first end and the second end of the first capacitor, and the differential signal processing module is configured to detect a first differential voltage signal between the first end and the second end of the first capacitor, and convert the first differential voltage signal into a corresponding single-ended voltage signal, and the single-ended voltage signal is used to determine the current flowing through the current loop to be detected.

[0005] In one embodiment, the differential signal processing module includes a temperature compensation unit, the input end of the temperature compensation unit is connected to the first end and the second end of the first capacitor, and the temperature compensation unit is configured to perform temperature compensation on the first differential voltage signal to output a second differential voltage signal; a differential amplifier unit, the input end of the differential amplifier unit is connected to the output end of the temperature compensation unit, and the differential amplifier unit is configured to perform differential amplification on the second differential voltage signal to output a first voltage signal; a voltage following unit, the input end of the voltage following unit is connected to the first end of the first capacitor, and the voltage following unit is configured to output a corresponding second voltage signal based on the voltage of the first end of the first capacitor; a voltage subtraction unit, the first input end of the voltage subtraction unit is connected to the output end of the differential amplifier unit, the second input end of the voltage subtraction unit is connected to the output end of the voltage following unit, and the voltage subtraction unit is configured to output a single-ended voltage signal based on the difference between the first voltage signal and the second voltage signal.

[0006] In one embodiment, the temperature compensation unit includes: a second resistor, a first end of the second resistor is connected to the first end of the first capacitor; a third resistor, a first end of the third resistor is connected to the second end of the first capacitor; a fourth resistor, a first end of the fourth resistor is connected to the second end of the third resistor, and the second end of the fourth resistor is connected to the output end of the differential amplifier unit.

[0007] In one embodiment, the differential amplification unit includes a first operational amplifier, a first input terminal of the first operational amplifier is connected to the second end of the second resistor, a second input terminal of the first operational amplifier is connected to the second end of the third resistor, and an output terminal of the first operational amplifier is configured to output a first voltage signal.

[0008] In one embodiment, the voltage follower unit includes a second operational amplifier, a first input terminal of the second operational amplifier is connected to the first end of the first capacitor, and an output terminal of the second operational amplifier is configured to output a second voltage signal; and a fifth resistor, a first end of the fifth resistor is connected to the second input terminal of the second operational amplifier, and a second end of the fifth resistor is connected to the output terminal of the second operational amplifier.

[0009] In one embodiment, the voltage subtraction unit includes a third operational amplifier, a first input terminal of the third operational amplifier is connected to the output terminal of the first operational amplifier, a second input terminal of the third operational amplifier is connected to the output terminal of the second operational amplifier, and the output terminal of the third operational amplifier is configured to output a single-ended voltage signal; a sixth resistor, a first end of the sixth resistor is connected to the output terminal of the second operational amplifier; a seventh resistor, a first end of the seventh resistor is connected to the second end of the sixth resistor, and the second end of the seventh resistor is connected to the output terminal of the third operational amplifier; an eighth resistor, a first end of the eighth resistor is connected to the output terminal of the first operational amplifier, and a second end of the eighth resistor is connected to the first input terminal of the third operational amplifier; a ninth resistor, a first end of the ninth resistor is connected to the first input terminal of the third operational amplifier, and a second end of the ninth resistor is grounded.

[0010] In one embodiment, the differential amplifier unit further includes a second capacitor, a first end of the second capacitor is connected to the first power supply terminal of the first operational amplifier and ground, and a second end of the second capacitor is connected to the output terminal of the first operational amplifier.

[0011] In one embodiment, the voltage follower unit further includes a third capacitor, a first end of the third capacitor is connected to the output end of the second operational amplifier, and a second end of the third capacitor is grounded.

[0012] In one embodiment, the voltage subtraction unit further includes a fourth capacitor, a first end of the fourth capacitor is connected to the output end of the third operational amplifier, and a second end of the fourth capacitor is connected to the second end of the ninth resistor.

[0013] The present application also provides an electronic device, which includes the current detection circuit as described above.

[0014] The current detection circuit of the present application includes: an inductor, which is arranged in a current loop to be detected; a first resistor, wherein the first end of the first resistor is connected to the first end of the inductor; a first capacitor, wherein the first end of the first capacitor is connected to the second end of the first resistor, and the second end of the first capacitor is connected to the second end of the inductor; a differential signal processing module, which connects the first end and the second end of the first capacitor, and the differential signal processing module is configured to detect a first differential voltage signal between the first end and the second end of the first capacitor, and convert the first differential voltage signal into a corresponding single-ended voltage signal, and the single-ended voltage signal is used to determine the current flowing through the current loop to be detected. In the above manner, when performing circuit current detection, the solution cost can be greatly reduced and the product flexibility can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] in:

[0017] Figure 1 is a structural schematic diagram of a first embodiment of a current detection circuit provided by the present application;

[0018] Figure 2 is a structural schematic diagram of a second embodiment of a current detection circuit provided by the present application;

[0019] Figure 3 is a temperature characteristic curve of the parasitic resistance Rdc of the second embodiment of the current detection circuit provided by the present application;

[0020] Figure 4 is the inductor temperature characteristic curve of the second embodiment of the current detection circuit provided by the present application;

[0021] Figure 5 It is a structural schematic diagram of an embodiment of an electronic device provided by the present application. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It will be appreciated that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some but not all structures related to the present application are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present application.

[0023] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0024] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0025] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of the first embodiment of the current detection circuit provided in the present application. The current detection circuit 100 includes an inductor L, a first resistor R1 , a first capacitor C1 and a differential signal processing module 10 .

[0026] Among them, the inductor L is arranged in the current loop to be detected; the first end of the first resistor R1 is connected to the first end of the inductor L; the first end of the first capacitor C1 is connected to the second end of the first resistor R1, and the second end of the first capacitor C1 is connected to the second end of the inductor L; the differential signal processing module 10 is connected to the first end and the second end of the first capacitor C1, and the differential signal processing module 10 is configured to detect a first differential voltage signal S1 between the first end and the second end of the first capacitor C1, and convert the first differential voltage signal S1 into a corresponding single-ended voltage signal Vo, and the single-ended voltage signal Vo is used to determine the current flowing through the current loop to be detected.

[0027] Specifically, the current of the current loop to be detected is the current IL flowing through the two ends of the inductor L, and the two ends of the inductor L are connected in parallel with the first resistor R1 and the first capacitor C1. When the first resistor R1 and the first capacitor C1 can form a loop with the inductor L and the parasitic resistance Rdc (not shown in the figure) of the inductor L, the differential voltage VL across the inductor L can be equivalently replaced by measuring the first differential voltage signal S1 across the first capacitor C1. The parasitic resistance Rdc can also be expressed as DCR (DC Resistance), which represents the resistance of the inductor coil under non-alternating current (direct current).

[0028] Specifically, the value of the first differential voltage signal S1 can be expressed as:

[0029]

[0030] Specifically, That is, when and only when the product of the resistance of the first resistor R1 and the capacitance of the first capacitor C1 is equal to the ratio of the inductance of the inductor L to the resistance of the parasitic resistance Rdc of the inductor L, the first differential voltage signal S1 across the first capacitor C1 can be equivalent to replacing the differential voltage VL across the inductor L. That is, if the differential voltage across the inductor L is obtained, the current IL flowing through the inductor L can be obtained, and the current IL is the ratio of the voltage across the inductor to the parasitic resistance Rdc.

[0031] See also Figure 2 , Figure 3 and Figure 4 , Figure 2 is a schematic structural diagram of a second embodiment of a current detection circuit provided in the present application. The current detection circuit 100 includes an inductor L, a first resistor R1 , a first capacitor C1 and a differential signal processing module 10 .

[0032] Among them, the inductor L is arranged in the current loop to be detected; the first end of the first resistor R1 is connected to the first end of the inductor L; the first end of the first capacitor C1 is connected to the second end of the first resistor R1, and the second end of the first capacitor C1 is connected to the second end of the inductor L; the differential signal processing module 10 is connected to the first end and the second end of the first capacitor C1, and the differential signal processing module 10 is configured to detect a first differential voltage signal S1 between the first end and the second end of the first capacitor C1, and convert the first differential voltage signal S1 into a corresponding single-ended voltage signal Vo, and the single-ended voltage signal Vo is used to determine the current flowing through the current loop to be detected.

[0033] Optionally, the differential signal processing module 10 includes a temperature compensation unit 11, a differential amplifier unit 12, a voltage follower unit 13 and a voltage subtraction unit 14. The input end of the temperature compensation unit 11 is connected to the first end and the second end of the first capacitor C1, and the temperature compensation unit 11 is configured to perform temperature compensation on the first differential voltage signal S1 to output the second differential voltage signal S2; the input end of the differential amplifier unit 12 is connected to the output end of the temperature compensation unit 11, and the differential amplifier unit 12 is configured to perform differential amplification on the second differential voltage signal S2 to output the first voltage signal V1; the input end of the voltage follower unit 13 is connected to the first end of the first capacitor C1, and the voltage follower unit 13 is configured to output the corresponding second voltage signal V2 based on the voltage of the first end of the first capacitor C1; the first input end of the voltage subtraction unit 14 is connected to the output end of the differential amplifier unit 12, the second input end of the voltage subtraction unit 14 is connected to the output end of the voltage follower unit 13, and the voltage subtraction unit 14 is configured to output a single-ended voltage signal Vo based on the difference between the first voltage signal V1 and the second voltage signal V2.

[0034] Optionally, the temperature compensation unit 11 includes a second resistor R2, a third resistor R3 and a fourth resistor R4, the first end of the second resistor R2 is connected to the first end of the first capacitor C1; the first end of the third resistor R3 is connected to the second end of the first capacitor C1; the first end of the fourth resistor R4 is connected to the second end of the third resistor R3, and the second end of the fourth resistor R4 is connected to the output end of the differential amplifier unit 12.

[0035] Specifically, when the first differential voltage signal S1 across the first capacitor C1 can be equivalent to the differential voltage VL across the inductor L, so that the current IL flowing through the inductor L is the ratio of the voltage across the inductor to the parasitic resistance Rdc, the resistance of the parasitic resistance Rdc of the inductor will change with the temperature, thereby affecting the accuracy of the detection current. Therefore, the temperature compensation unit 11 is added to avoid this temperature effect. Because the parasitic resistance Rdc is a resistor with a positive temperature coefficient, the resistance value increases with the increase of temperature, so it is necessary to insert a resistive network with a negative temperature coefficient in the current loop to be detected to compensate for the offset caused by the resistance value of the parasitic resistance Rdc changing with the temperature.

[0036] Optionally, the differential amplifier unit 12 includes a first operational amplifier U1, a first input terminal of the first operational amplifier U1 is connected to the second end of the second resistor R2, a second input terminal of the first operational amplifier U1 is connected to the second end of the third resistor R3, and an output terminal of the first operational amplifier U1 is configured to output a first voltage signal V1.

[0037] Optionally, the differential amplifier unit 12 further includes a second capacitor C2, a first end of the second capacitor C2 is connected to the first power supply terminal of the first operational amplifier U1 and ground, and a second end of the second capacitor C2 is connected to the output terminal of the first operational amplifier U1.

[0038] The value of the first differential voltage signal S1 is the difference between the voltage value S1+ at the second end of the first capacitor C1 and the voltage value S1 − at the first end of the first capacitor C1 .

[0039] Specifically, the first operational amplifier U1 is used to amplify the difference between the two input terminal voltages with a fixed gain, that is, to amplify the difference of the second differential voltage signal S2 after temperature compensation and output the first voltage signal V1. The value of the first voltage signal V1 is:

[0040]

[0041] Optionally, the voltage follower unit 13 includes a second operational amplifier U2 and a fifth resistor R5, the first input terminal of the second operational amplifier U2 is connected to the first end of the first capacitor C1, and the output terminal of the second operational amplifier U2 is configured to output a second voltage signal V2; the first end of the fifth resistor R5 is connected to the second input terminal of the second operational amplifier U2, and the second end of the fifth resistor R5 is connected to the output terminal of the second operational amplifier U2.

[0042] Optionally, the voltage follower unit 13 further includes a third capacitor C3, a first end of the third capacitor C3 is connected to the output end of the second operational amplifier U2, and a second end of the third capacitor C3 is grounded.

[0043] Specifically, the voltage follower unit 13 is configured to output a corresponding second voltage signal V2 based on the voltage at the first end of the first capacitor C1. The second operational amplifier U2 is an operational amplifier with a voltage gain of 1, which means that the second operational amplifier U2 does not amplify the voltage at its input end, that is, the output voltage of the second operational amplifier U2 is the same as the voltage at the first end of the first capacitor C1. The value of the second voltage signal V2 is S1-.

[0044] Optionally, the voltage subtraction unit 14 includes a third operational amplifier U3, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9. A first input terminal of the third operational amplifier U3 is connected to an output terminal of the first operational amplifier U1, a second input terminal of the third operational amplifier U3 is connected to an output terminal of the second operational amplifier U2, and an output terminal of the third operational amplifier U3 is configured to output a single-ended voltage signal Vo; a first terminal of the sixth resistor R6 is connected to an output terminal of the second operational amplifier U2; a first terminal of the seventh resistor R7 is connected to a second terminal of the sixth resistor R6, and a second terminal of the seventh resistor R7 is connected to an output terminal of the third operational amplifier U3; a first terminal of the eighth resistor R8 is connected to an output terminal of the first operational amplifier U1, and a second terminal of the eighth resistor R8 is connected to a first input terminal of the third operational amplifier U3; a first terminal of the ninth resistor R9 is connected to a first input terminal of the third operational amplifier U3, and a second terminal of the ninth resistor R9 is grounded.

[0045] Optionally, the voltage subtraction unit 14 further includes a fourth capacitor C4, a first end of the fourth capacitor C4 is connected to the output end of the third operational amplifier U3, and a second end of the fourth capacitor C4 is connected to the second end of the ninth resistor R9.

[0046] Specifically, the third operational amplifier U3 is based on the virtual short and virtual open principles. The virtual short refers to that when the operational amplifier is in a linear state, the two input terminals are regarded as equal potential, that is, the voltages of the positive input terminal and the negative input terminal of the operational amplifier are equal. The virtual open refers to that when the operational amplifier is in a linear state, the two input terminals are regarded as open circuits, that is, the current flowing into the positive and negative input terminals is zero. In one embodiment, when the resistance value of the eighth resistor R8 is equal to the resistance value of the sixth resistor R6, and the resistance value of the ninth resistor R9 is equal to the resistance value of the seventh resistor R7, according to the virtual short and virtual open principles, the value of the single-ended voltage signal Vo is calculated:

[0047]

[0048] Specifically, the value of the single-ended voltage signal Vo is consistent with the voltage value of the first differential voltage signal S1, that is, it is also consistent with the voltage flowing through the two ends of the inductor L. Therefore, the current IL flowing through the two ends of the inductor L is:

[0049]

[0050] In some optional embodiments, such as Figure 3 As shown, Figure 3 4 is a temperature characteristic curve of the parasitic resistance Rdc of the second embodiment of the current detection circuit provided by the present application.

[0051] Since the temperature offset of the parasitic resistance Rdc does not show a proportional characteristic, it can be used to make segmented compensation circuits based on the application scenario. For example, if the current needs to be protected at high temperatures, it is necessary to compensate for the offset of the parasitic resistance Rdc in the high temperature range. For example, when the voltage across the inductor is 0.2V and the temperature is 25 degrees Celsius, the offset of the parasitic resistance Rdc is about 10 3 Hz, and as the temperature increases, the offset of the parasitic resistance Rdc also increases; the greater the voltage across the inductor, the greater the offset of the parasitic resistance Rdc at the same temperature.

[0052] In some optional embodiments, such as Figure 4 As shown, Figure 4 1 is the inductor temperature characteristic curve of the second embodiment of the current detection circuit provided in the present application.

[0053] The inductance of the inductor L also shifts under different temperature conditions, so it is necessary to calibrate the inductance offset of the high temperature section inductor L and put it into the temperature compensation circuit, so as to achieve the actual application of being able to accurately measure the current in the application. For example, when the temperature is 80 degrees Celsius, the inductance of the inductor is about 4.0uH, and the current flowing through the inductor is about 10.3A. When the temperature is 90 degrees Celsius, the inductance of the inductor is about 4.5uH, and the current flowing through the inductor is in the range of 0-2A, that is, the higher the temperature, the greater the inductance of the inductor, and the smaller the current flowing through the inductor.

[0054] See also Figure 5 , Figure 5 1 is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. The electronic device 500 includes a current detection circuit 100, and the current detection circuit 100 is as described in the above embodiment, and will not be described in detail here.

[0055] When the protection circuit of this embodiment is applied to electronic equipment, the actual current trend and size in the circuit are reflected by detecting the current flowing through the inductor connected in series in the circuit. The circuit to be tested itself does not consume power, and the inductor can be connected in series at any point in the circuit, thereby reducing the cost of current detection and improving product flexibility.

[0056] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A current detection circuit, characterized in that: The current detection circuit comprises: An inductor is arranged in a current loop to be detected; a first resistor, wherein a first end of the first resistor is connected to a first end of the inductor; A first capacitor, wherein a first end of the first capacitor is connected to a second end of the first resistor, and a second end of the first capacitor is connected to a second end of the inductor; A differential signal processing module is connected to the first end and the second end of the first capacitor, and the differential signal processing module is configured to detect a first differential voltage signal between the first end and the second end of the first capacitor, and convert the first differential voltage signal into a corresponding single-ended voltage signal, and the single-ended voltage signal is used to determine the current flowing through the current loop to be detected.

2. The current detection circuit according to claim 1, characterized in that: The differential signal processing module comprises: a temperature compensation unit, wherein an input end of the temperature compensation unit is connected to a first end and a second end of the first capacitor, and the temperature compensation unit is configured to perform temperature compensation on the first differential voltage signal to output a second differential voltage signal; a differential amplification unit, wherein an input end of the differential amplification unit is connected to an output end of the temperature compensation unit, and the differential amplification unit is configured to differentially amplify the second differential voltage signal to output a first voltage signal; a voltage following unit, wherein an input end of the voltage following unit is connected to the first end of the first capacitor, and the voltage following unit is configured to output a corresponding second voltage signal based on the voltage of the first end of the first capacitor; A voltage subtraction unit, wherein the first input terminal of the voltage subtraction unit is connected to the output terminal of the differential amplifier unit, the second input terminal of the voltage subtraction unit is connected to the output terminal of the voltage follower unit, and the voltage subtraction unit is configured to output the single-ended voltage signal based on the difference between the first voltage signal and the second voltage signal.

3. The current detection circuit according to claim 2, characterized in that: The temperature compensation unit comprises: a second resistor, wherein a first end of the second resistor is connected to a first end of the first capacitor; a third resistor, a first end of the third resistor being connected to the second end of the first capacitor; A fourth resistor, wherein a first end of the fourth resistor is connected to the second end of the third resistor, and a second end of the fourth resistor is connected to the output end of the differential amplification unit.

4. The current detection circuit according to claim 3, characterized in that: The differential amplification unit comprises: A first operational amplifier, wherein a first input terminal of the first operational amplifier is connected to a second terminal of the second resistor, a second input terminal of the first operational amplifier is connected to a second terminal of the third resistor, and an output terminal of the first operational amplifier is configured to output the first voltage signal.

5. The current detection circuit according to claim 4, characterized in that: The voltage follower unit comprises: a second operational amplifier, wherein a first input terminal of the second operational amplifier is connected to a first terminal of the first capacitor, and an output terminal of the second operational amplifier is configured to output the second voltage signal; A fifth resistor, wherein a first end of the fifth resistor is connected to the second input end of the second operational amplifier, and a second end of the fifth resistor is connected to the output end of the second operational amplifier.

6. The current detection circuit according to claim 5, characterized in that: The voltage subtraction unit comprises: a third operational amplifier, wherein a first input terminal of the third operational amplifier is connected to an output terminal of the first operational amplifier, a second input terminal of the third operational amplifier is connected to an output terminal of the second operational amplifier, and an output terminal of the third operational amplifier is configured to output the single-ended voltage signal; a sixth resistor, a first end of the sixth resistor being connected to the output end of the second operational amplifier; a seventh resistor, wherein a first end of the seventh resistor is connected to a second end of the sixth resistor, and a second end of the seventh resistor is connected to an output end of the third operational amplifier; an eighth resistor, wherein a first end of the eighth resistor is connected to the output end of the first operational amplifier, and a second end of the eighth resistor is connected to the first input end of the third operational amplifier; A ninth resistor, wherein a first end of the ninth resistor is connected to the first input end of the third operational amplifier, and a second end of the ninth resistor is grounded.

7. The current detection circuit according to claim 4, characterized in that: The differential amplifier unit further includes a second capacitor, a first end of the second capacitor is connected to the first power supply terminal of the first operational amplifier and the ground, and a second end of the second capacitor is connected to the output terminal of the first operational amplifier.

8. The current detection circuit according to claim 5, characterized in that: The voltage follower unit further includes a third capacitor, a first end of the third capacitor is connected to the output end of the second operational amplifier, and a second end of the third capacitor is grounded.

9. The current detection circuit according to claim 6, characterized in that: The voltage subtraction unit further includes a fourth capacitor, a first end of the fourth capacitor is connected to the output end of the third operational amplifier, and a second end of the fourth capacitor is connected to the second end of the ninth resistor.

10. An electronic device, characterized in that: The electronic device comprises the current detection circuit as claimed in any one of claims 1 to 9.

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