CN118330297A - Current detection circuit, current detector and electronic device - Google Patents

Abstract

The present application discloses a current detection circuit, a current detector and an electronic device, and relates to the field of circuit technology. The current detection circuit includes a first shunt unit, a second shunt unit, a voltage adjustment unit, a first resistor and a processing unit. When the current detection circuit is working, the first resistor is a sampling resistor, and the current of the first resistor is less than the current of the load. The processing unit is used to determine the current of the first resistor according to the voltage of the first resistor, and then determine the current of the load according to the current of the first resistor, the current of the first shunt unit and the ratio of the current of the second shunt unit. In this way, the power loss caused by the sampling resistor can be reduced by making the current of the sampling resistor less than the current of the load while ensuring the detection accuracy of the current detection circuit, thereby improving the endurance of the electronic device.

Description

Current detection circuit, current detector and electronic device

Technical Field

The present application relates to the field of circuit technology, and in particular to a current detection circuit, a current detector and an electronic device.

Background technique

Electronic devices such as mobile phones, tablet computers, and laptop computers usually have current detection circuits, which are used to detect the current of loads such as central processing units, graphics processors, and baseband processors.

In the related art, the current detection circuit usually includes a sampling resistor and a processing unit. The sampling resistor is connected in series with the load. The processing unit detects the voltage of the sampling resistor and obtains the current of the sampling resistor according to the voltage of the sampling resistor and the resistance value of the sampling resistor, thereby obtaining the current of the load. Generally, in order to ensure the detection accuracy of the current detection circuit, the resistance value of the sampling resistor cannot be too small.

However, in the related art, if the resistance of the sampling resistor is large, it will cause a large power loss and affect the endurance of the electronic device.

Summary of the invention

The present application provides a current detection circuit, a current detector and an electronic device, which can not only ensure the detection accuracy of the current detection circuit, but also reduce the power loss caused by the sampling resistor, thereby improving the endurance of the electronic device. The technical solution is as follows:

In a first aspect, a current detection circuit is provided, comprising a first shunt unit, a second shunt unit, a voltage regulating unit, a first resistor and a processing unit.

The first shunt unit is used to be connected in series with the load between the first voltage terminal and the second voltage terminal. The voltage of the first voltage terminal is greater than the voltage of the second voltage terminal to form a first current path starting from the first voltage terminal, passing through the first shunt unit and the load to the second voltage terminal. In some specific embodiments, the second voltage terminal can be a ground line.

The first end of the second shunt unit is connected to the first end of the first shunt unit, so that the voltage of the first end of the second shunt unit is equal to the voltage of the first end of the first shunt unit. The second end of the first shunt unit is connected to the first end of the voltage regulating unit, and the second end of the second shunt unit is connected to the second end of the voltage regulating unit. When the current detection circuit is working, the voltage of the first end and the second end of the voltage regulating unit are the same, that is, the voltage of the second end of the first shunt unit is equal to the voltage of the second end of the second shunt unit.

The first resistor is connected between the second end of the second shunt unit and the second voltage end to form a second current path starting from the first voltage end, passing through the second shunt unit and the first resistor to reach the second voltage end. The second current path may also further include a load. The processing unit is connected to the first resistor to detect the voltage of the first resistor. When the processing unit is working, it is used to: determine the current of the load according to the voltage of the first resistor and the target ratio. The target ratio is the ratio of the current of the first shunt unit to the current of the second shunt unit when the current detection circuit is working. When the second shunt unit is connected in parallel with the load, that is, when the second current path does not include the load, the target ratio is greater than 1; when the second shunt unit is connected in series with the load, that is, when the second circuit path includes the load, the target ratio is greater than 0.

In the present application, the current detection circuit includes a first shunt unit, a second shunt unit, a voltage regulating unit, a first resistor and a processing unit, and the current path formed includes a first current path and a second current path. The first current path includes a first shunt unit and a load connected in series, and the second current path includes a second shunt unit and a first resistor connected in series. The first resistor is a sampling resistor. The voltage regulating unit is used to make the voltage at both ends of the first shunt unit the same as the voltage at both ends of the second shunt unit, so that the current of the first shunt unit and the current of the second shunt unit have a target ratio when the current detection circuit is working. When the processing unit is working, the current of the first resistor can be determined according to the voltage of the first resistor, and then the current of the load can be determined according to the current of the first resistor and the target ratio, so as to achieve the purpose of current detection. Here, when the second current path does not include the load, that is, when the second shunt unit is connected in parallel with the load, the target ratio is greater than 1. At this time, the current of the second shunt unit is equal to the current of the first resistor, and is less than the current of the first shunt unit, that is, less than the current of the load. When the second current path includes the load, that is, when the second shunt unit is connected in series with the load, the target ratio is greater than 0. At this time, the current of the load is equal to the current of the first shunt unit plus the current of the second shunt unit, so the current of the second shunt unit is also equal to the current of the first resistor, and is less than the current of the load. In this way, the power loss caused by the sampling resistor can be reduced by making the current of the sampling resistor less than the current of the load while ensuring the detection accuracy of the current detection circuit, thereby improving the endurance of the electronic device. In other words, compared with the related art, when the resistance value of the sampling resistor remains unchanged, the present application reduces the power loss caused by the sampling resistor by reducing the current of the sampling resistor.

In some embodiments, the first shunt unit includes a plurality of transistors. The first electrodes of the plurality of transistors are connected to the first end of the second shunt unit. The second electrodes of the plurality of transistors are connected to the first end of the voltage regulating unit. The processing unit has a plurality of output terminals, and the plurality of output terminals of the processing unit are connected to the control electrodes of the plurality of transistors one by one to control the on and off of each of the plurality of transistors. The processing unit is further used to determine the target ratio according to the number of transistors in the on state among the plurality of transistors.

Further, the processing unit is also used to: adjust the number of transistors in the on state among the multiple transistors according to the voltage of the first resistor. That is to say, in this embodiment, the processing unit can adjust the number of transistors in the on state among the multiple transistors of the first shunt unit according to the voltage of the first resistor, thereby adjusting the ratio of the current of the first shunt unit to the current of the second shunt unit. Specifically, a preset voltage range can be provided in the processing unit. When the processing unit is working, it is used to: if the voltage of the first resistor is greater than the maximum value of the preset voltage range, increase the number of transistors in the on state among the multiple transistors of the first shunt unit, so that the voltage of the first resistor is within the preset voltage range. And, if the voltage of the first resistor is less than the minimum value of the preset voltage range, reduce the number of transistors in the on state among the multiple transistors of the first shunt unit, so that the voltage of the first resistor is within the preset voltage range. In this way, whether the current of the load is large or small, the voltage of the first resistor can be kept within the preset voltage range, so that the current detection accuracy can be guaranteed on the one hand, and the power loss caused by the sampling resistor can be reduced on the other hand.

In some specific embodiments, the ratio of the channel width to the channel length of each transistor in the plurality of transistors in the first shunting unit is equal.

In some embodiments, the second shunt unit includes a first transistor. A first electrode of the first transistor is connected to a first end of the first shunt unit, and a second electrode of the first transistor is connected to a second end of the voltage regulating unit. When the current detection circuit is working, the first transistor is turned on.

In some embodiments, the voltage regulating unit includes: an operational amplifier and a switching transistor. The first input terminal of the operational amplifier is connected to the second terminal of the first shunt unit, the second input terminal of the operational amplifier is connected to the second terminal of the second shunt unit and the first terminal of the first resistor, and the output terminal of the operational amplifier is connected to the control electrode of the switching transistor. The second terminal of the first resistor is connected to the first electrode of the switching transistor, and the second electrode of the switching transistor is used to be connected to the second voltage terminal.

The current detection circuit provided in the present application is explained below from three possible implementation methods.

In a first possible implementation, the first end of the first shunt unit is used to connect to the first voltage end, the second end of the first shunt unit is used to connect to the first end of the load, and the second end of the load is connected to the second voltage end. The first end of the first resistor is connected to the second end of the second shunt unit, and the second end of the first resistor is used to connect to the second end of the load. In this case, the second current path does not include the load, that is, the second shunt unit is connected in parallel with the load. At this time, the processing unit is used to: determine the current of the first resistor according to the voltage of the first resistor and the resistance value of the first resistor; multiply the current of the first resistor by the target ratio to obtain the current of the load.

In a second possible implementation, the first end of the first shunt unit is used to be connected to the first voltage end, the second end of the first shunt unit is used to be connected to the first end of the load, and the second end of the load is connected to the second voltage end. The first end of the first resistor is connected to the second end of the second shunt unit, and the second end of the first resistor is used to be connected to the first end of the load. In this case, the second current path includes the load, that is, the second shunt unit is connected in series with the load. At this time, the processing unit is used to: determine the current of the first resistor based on the voltage of the first resistor and the resistance value of the first resistor. The product of the current of the first resistor and K+1 is determined as the current of the load, and K is the target ratio.

In a third possible implementation, the current detection circuit further includes: a second resistor. The first end of the load is used to be connected to the first voltage end, the first end of the first shunt unit is used to be connected to the second end of the load, the second end of the first shunt unit is connected to the first end of the second resistor, and the second end of the second resistor is used to be connected to the second voltage end. The first end of the first resistor is connected to the second end of the second shunt unit, and the second end of the first resistor is connected to the second end of the second resistor. In this case, the second current path includes the load, that is, the second shunt unit is connected in series with the load. At this time, the processing unit is used to: determine the current of the first resistor according to the voltage of the first resistor and the resistance value of the first resistor. The product of the current of the first resistor and K+1 is determined as the current of the load, and K is the target ratio.

In a second aspect, a current detector is provided, comprising a current detection circuit as in any one of the first aspect.

In a third aspect, an electronic device is provided, comprising the current detection circuit in any one of the first aspect or the current detector in the second aspect.

The technical effects obtained by the above-mentioned second and third aspects are similar to the technical effects obtained by the corresponding technical means in the above-mentioned first aspect, and will not be repeated here.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the appearance of an electronic device in the related art;

FIG2 is a circuit structure diagram of a current detection circuit in the related art;

FIG3 is a circuit structure diagram of a first current detection circuit provided in an embodiment of the present application;

FIG4 is a circuit structure diagram of a second current detection circuit provided in an embodiment of the present application;

FIG5 is a circuit structure diagram of a third current detection circuit provided in an embodiment of the present application;

FIG6 is a circuit diagram of a first current detection circuit provided in an embodiment of the present application;

7 is a circuit diagram of a second current detection circuit provided in an embodiment of the present application;

FIG8 is a circuit diagram of a third current detection circuit provided in an embodiment of the present application;

9 is a circuit diagram of a fourth current detection circuit provided in an embodiment of the present application;

FIG10 is a circuit diagram of a fifth current detection circuit provided in an embodiment of the present application;

FIG. 11 is a voltage simulation diagram of a first transistor and a first resistor provided in an embodiment of the present application.

The meanings of the figures are as follows:

Related technologies:

10. Electronic equipment;

110. Current detection circuit;

112. Processing unit;

120, load;

This application:

20. Current detection circuit;

210, first diversion unit;

220, second diversion unit;

230. Voltage regulating unit;

240, processing unit;

30. Load.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

It should be understood that the "multiple" mentioned in this application refers to two or more. In the description of this application, unless otherwise specified, "/" means or, for example, A/B can mean A or B; "and/or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and/or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in order to facilitate the clear description of the technical solution of this application, the words "first" and "second" are used to distinguish between the same or similar items with basically the same functions and effects. Those skilled in the art can understand that the words "first" and "second" do not limit the quantity and execution order, and the words "first" and "second" do not limit them to be different.

Before explaining the current detection circuit provided in the embodiment of the present application in detail, the application scenario of the current detection circuit is first explained.

Electronic devices include smart screens (i.e., TVs), mobile phones, tablet computers, laptop computers, etc. Taking the mobile phone as an example, FIG1 is a schematic diagram of the appearance of an electronic device 10 in the related art. The electronic device 10 usually has a current detection circuit, which is used to detect the current of loads such as a central processing unit (CPU), a graphics processing unit (GPU), a baseband processor, etc. in the electronic device.

FIG2 is a circuit diagram of a current detection circuit 110 in the related art. As shown in FIG2, in the related art, the current detection circuit 110 includes a sampling resistor R1 and a processing unit 112. The sampling resistor R1 and the load 120 are connected in series between the voltage terminal V1 and the ground line GND. When the processing unit 112 is working, the voltage of the sampling resistor R1 can be detected, and the current of the sampling resistor R1 can be calculated according to the following formula.

Wherein, U _drop is the voltage of the sampling resistor R1 detected by the processing unit 112, R is the resistance value of the sampling resistor R1, and I is the current of the sampling resistor R1 calculated by the processing unit. The resistance value of the sampling resistor R1 can be preset in the processing unit 112. Since the sampling resistor R1 is connected in series with the load 120, the current of the sampling resistor R1 calculated by the processing unit is equal to the current of the load 120.

In the related art, if the resistance of the sampling resistor R1 is too small, according to U _drop =IR, the voltage of the sampling resistor R1 is too small, which will affect the detection accuracy of the current detection circuit 110. Therefore, to ensure the detection accuracy of the current detection circuit 110, the resistance of the sampling resistor R1 cannot be too small.

However, according to P=I ² R, where P is the working power of the sampling resistor R1 , if the resistance of the sampling resistor R1 is large, the sampling resistor R1 will cause a large power loss, thereby affecting the endurance of the electronic device 10 .

To this end, the embodiments of the present application provide a current detection circuit, a current detector and an electronic device, which can not only ensure the detection accuracy of the current detection circuit, but also reduce the power loss caused by the sampling resistor, thereby improving the endurance of the electronic device.

The current detection circuit provided in the embodiment of the present application is explained in detail below. The current detection circuit provided in the embodiment of the present application can be applied to electronic devices to detect the current of loads such as CPU, GPU, baseband processor, etc. in electronic devices. In the embodiment of the present application, the connection between two electronic devices or/and electrical units is an electrical connection, and the electrical connection here refers to the connection between the two electronic devices or/and electrical units through a wire to transmit electrical signals. In addition, the electrical connection between the two electronic devices or/and electrical units can be a direct connection through a wire, or it can be an indirect connection through other electronic devices or/and electrical units.

FIG3 is a circuit structure diagram of a current detection circuit 20 provided in an embodiment of the present application. As shown in FIG3 , the current detection circuit 20 includes a first shunt unit 210 , a second shunt unit 220 , a voltage adjustment unit 230 , a first resistor R1 and a processing unit 240 .

The first shunt unit 210 and the second shunt unit 220 are used to shunt the main current of the current detection circuit 20. Among them, the first shunt unit 210 and the load 30 are connected in series between the first voltage terminal V1 and the second voltage terminal V2. In an embodiment of the present application, the voltage of the first voltage terminal V1 is greater than the voltage of the second voltage terminal V2. In this way, a first current path can be formed starting from the first voltage terminal V1, passing through the first shunt unit 210 and the load 30 to reach the second voltage terminal V2. In some embodiments, the voltage of the first voltage terminal V1 can be 5V (volts), 8V or 10V; the voltage of the second voltage terminal V2 can be 2V, 0 or -2V. In some specific embodiments, the second voltage terminal V2 can be a ground wire GND, that is, the voltage of the second voltage terminal V2 is 0.

The first end of the second shunt unit 220 is connected to the first end of the first shunt unit 210, so that the voltage of the first end of the second shunt unit 220 is equal to the voltage of the first end of the first shunt unit 210. The voltage regulating unit 230 has a first end a and a second end b. When the voltage regulating unit 230 is working, the voltages of the first end a and the second end b of the voltage regulating unit 230 are equal. The second end of the first shunt unit 210 is connected to the first end a of the voltage regulating unit 230, and the second end of the second shunt unit 220 is connected to the second end b of the voltage regulating unit 230. That is, when the voltage regulating unit 230 is working, the voltage of the second end of the first shunt unit 210 is equal to the voltage of the second end of the second shunt unit 220. In this way, when the current detection circuit 20 is working, the voltage across the first shunt unit 210 is equal to the voltage across the second shunt unit 220.

In this case, the current of the first shunt unit 210 is: Wherein, _Ia is the current of the first shunt unit 210 , U is the voltage across the first shunt unit 210 , and Ra _is the resistance of the first shunt unit 210 .

The current of the second shunt unit 220 is: Wherein, I _b is the current of the second shunt unit 220 , U is the voltage across the second shunt unit 220 and is equal to the voltage across the first shunt unit 210 , and R _b is the resistance of the second shunt unit 220 .

At this time, the ratio of the current of the first shunt unit 210 to the current of the second shunt unit 220 is: For ease of description, the "ratio of the current of the first shunt unit 210 to the current of the second shunt unit 220" is referred to as a target ratio. That is, the current of the first shunt unit 210 can be obtained according to the current of the second shunt unit 220 and the target ratio; and the target ratio is only related to the resistance of the first shunt unit 210 and the resistance of the second shunt unit 220.

The first resistor R1 is a sampling resistor. The first resistor R1 is connected between the second end of the second shunt unit 220 and the second voltage terminal V2. In this way, a second current path can be formed starting from the first voltage terminal V1, passing through the second shunt unit 220 and the first resistor R1 to reach the second voltage terminal V2. It should be noted that in some embodiments of the present application, as shown in FIG3, the connection relationship between the second shunt unit 220, the first resistor R1 and the load 30 can be in parallel. In this case, the second current path does not include the load 30. Specifically, in the embodiment shown in FIG3, the current can be output from the first voltage terminal V1, and flow into the second voltage terminal V2 through the second shunt unit 220 and the first resistor R1 successively, without passing through the load 30. In some other embodiments of the present application, as shown in FIG4, the connection relationship between the second shunt unit 220, the first resistor R1 and the load 30 is in series. In this case, the second current path includes the load 30. Specifically, in the embodiment shown in FIG. 4 , the current may be output from the first voltage terminal V1 , and flow into the second voltage terminal V2 via the second shunt unit 220 , the first resistor R1 , and the load 30 .

As shown in FIGS. 3 and 4 , the processing unit 240 is connected to the first resistor R1 to detect the voltage of the first resistor R1. Here, the processing unit 240 may have a detection terminal c1 and a detection terminal c2, the detection terminal c1 of the processing unit 240 is connected to the first end of the first resistor R1, and the detection terminal c2 of the processing unit 240 is connected to the second end of the first resistor R1, so that the processing unit 240 can detect the voltage of the first resistor R1 when working. In some specific embodiments, the processing unit 240 may include a comparison amplifier, a digital to analog converter (DAC), an analog to digital converter (ADC), a processor, etc., which will not be repeated.

When the processing unit 240 is working, it is used to: determine the current of the load 30 according to the voltage of the first resistor R1 and the target ratio. Specifically, according to the above description, the first resistor R1 is connected in series with the second shunt unit 220, and the first resistor R1 is not connected in parallel with other electronic devices. Based on this, it can be obtained that when the current detection circuit 20 is working, the current of the second shunt unit 220 is equal to the current of the first resistor R1. The first resistor R1 is a sampling resistor and is a resistor with a fixed resistance. The resistance value of the first resistor R1 can be pre-stored in the processing unit 240. In this way, after the processing unit 240 detects the voltage of the first resistor R1, the current of the first resistor R1 can be obtained as: Wherein, I _R1 is the current of the first resistor R1, U _R1 is the voltage of the first resistor R1, and R is the resistance value of the first resistor R1. Thus, the current of the second shunt unit 220 can be obtained as: I _b =I _R1 .

In the first case, the second shunt unit 220 is connected in parallel with the load 30, that is, the second current path does not include the load 30. At this time, the current in the load 30 is equal to the current of the first shunt unit 210. That is, the current of the load 30 is: I _load =I _a =I _b ×K. Wherein, I _load is the current of the load 30, and K is the target ratio. In the embodiment of the present application, when the second shunt unit 220 is connected in parallel with the load 30, the target ratio is greater than 1. For example, the target ratio can be 2, 3, 5, 8 or 10. In this way, the current of the load 30 can be greater than the current of the second shunt unit 220, that is, the current of the load 30 is greater than the current of the first resistor R1. In this way, the power loss caused by the sampling resistor can be reduced by making the current of the sampling resistor less than the current of the load 30 while ensuring the detection accuracy of the current detection circuit 20, thereby improving the endurance of the electronic device. That is to say, compared with the related art, when the resistance value of the sampling resistor remains unchanged, the present application reduces the power loss caused by the sampling resistor by reducing the current of the sampling resistor.

In the second case, the second shunt unit 220 is connected in series with the load 30, that is, the second current path includes the load 30. At this time, the current in the load 30 is equal to the sum of the current of the first shunt unit 210 and the current of the second shunt unit 220. In other words, the current of the load 30 is: I _load =I _a +I _b =I _b ×K+I _b =I _b (K+1). In an embodiment of the present application, when the second shunt unit 220 is connected in series with the load 30, the target ratio is greater than 0. For example, the target ratio may be 0.2, 0.4, 0.8, 1, 2, 5, 8 or 10. In this way, the current of the load 30 can be greater than the current of the second shunt unit 220, that is, the current of the load 30 is greater than the current of the first resistor R1. In this way, the power loss caused by the sampling resistor can be reduced by making the current of the sampling resistor less than the current of the load 30 while ensuring the detection accuracy of the current detection circuit 20, thereby improving the endurance of the electronic device. That is to say, compared with the related art, when the resistance value of the sampling resistor remains unchanged, the present application reduces the power loss caused by the sampling resistor by reducing the current of the sampling resistor.

It can be understood that in the embodiments shown in FIG. 3 and FIG. 4 , the specific connection mode of “the first shunt unit 210 and the load 30 are connected in series between the first voltage terminal V1 and the second voltage terminal V2” is: the first end of the first shunt unit 210 is connected to the first voltage terminal V1, the second end of the first shunt unit 210 is connected to the first end of the load 30, and the second end of the load 30 is connected to the second voltage terminal V2. In this case, the first current path is: the current is output from the first voltage terminal V1, and flows into the second voltage terminal V2 through the first shunt unit 210 and the load 30 in sequence. In some other embodiments, as shown in FIG. 5 , the specific connection mode of “the first shunt unit 210 and the load 30 are connected in series between the first voltage terminal V1 and the second voltage terminal V2” is: the first end of the load 30 is used to connect to the first voltage terminal V1, the first end of the first shunt unit 210 is used to connect to the second end of the load 30, and the second end of the first shunt unit 210 is used to connect to the second voltage terminal V2. In the embodiment shown in FIG. 5 , the second end of the first shunt unit 210 is connected to the second voltage terminal V2 through the second resistor R2. In this case, the first current path is: the current is output from the first voltage terminal V1, and flows into the second voltage terminal V2 through the load 30, the first shunt unit 210, and the second resistor R2 in sequence.

It is understandable that in the above embodiment, for ease of understanding, the first voltage terminal V1, the second voltage terminal V2, and the load 30 are introduced to describe the connection mode and working process of the current detection circuit 20 provided in the embodiment of the present application. In fact, the current detection circuit 20 provided in the embodiment of the present application does not include the first voltage terminal V1, the second voltage terminal V2, and the load 30. In other words, the first voltage terminal V1, the second voltage terminal V2, and the load 30 exist as environmental elements relative to the current detection circuit 20 provided in the embodiment of the present application, and should not be understood as a limitation on the current detection circuit 20 provided in the embodiment of the present application.

In some embodiments, as a sampling resistor, the resistance of the first resistor R1 can be between 0.5KΩ (kilo-ohm) and 1.5KΩ. For example, the resistance of the first resistor R1 can be 0.5KΩ, 0.7KΩ, 0.8KΩ, 1KΩ, 1.2KΩ, 1.3KΩ or 1.5KΩ. In some specific embodiments, the resistance of the first resistor R1 is 1KΩ.

The following is a detailed explanation of the structure of each electrical unit from three possible situations in conjunction with the accompanying drawings. In the following three possible situations, the circuit diagrams involved (i.e., Figures 6 to 8) all correspond to the circuit structure diagram shown in Figure 3. In the embodiment of the present application, the transistors involved can all be metal oxide semiconductor field effect transistors (MOSFETs).

(1) In the first possible case, the target ratio is a constant.

FIG6 is a circuit diagram of a current detection circuit 20 provided in an embodiment of the present application. As shown in FIG6, in some embodiments, the second shunt unit 220 includes a first transistor T1. The first electrode of the first transistor T1 is connected to the first end of the first shunt unit 210. In other words, the first electrode of the first transistor T1 is the first end of the second shunt unit 220. The second electrode of the first transistor T1 is connected to the second end b of the voltage regulating unit 230. In other words, the second electrode of the first transistor T1 is the second end of the second shunt unit 220.

The first shunt unit 210 includes a plurality of transistors. Here, the plurality refers to two or more integers. For example, the first shunt unit 210 may include two transistors, five transistors, or eight transistors. In the embodiment shown in FIG6 , the first shunt unit 210 includes a second transistor T2, a third transistor T3, a fourth transistor T4 ... an eleventh transistor T11, a total of ten transistors. The first poles of the plurality of transistors in the first shunt unit 210 are all connected to the first end of the second shunt unit 220. That is, the first poles of the plurality of transistors in the first shunt unit 210 are connected together to form the first end of the first shunt unit 210. The second poles of the plurality of transistors in the first shunt unit 210 are all connected to the first end a of the voltage regulating unit 230. That is, the second poles of the plurality of transistors in the first shunt unit 210 are connected together to form the second end of the first shunt unit 210.

The voltage regulating unit 230 includes an operational amplifier A1 and a switching transistor T0. The first input terminal of the operational amplifier A1 is connected to the second terminal of the first shunt unit 210. That is, the first input terminal of the operational amplifier A1 is the first terminal a of the voltage regulating unit 230. The second input terminal of the operational amplifier A1 is connected to the second terminal of the second shunt unit 220 and the first terminal of the first resistor R1. That is, the second input terminal of the operational amplifier A1 is the second terminal b of the voltage regulating unit 230. In the embodiment shown in FIG6, the first input terminal of the operational amplifier A1 is the inverting input terminal of the operational amplifier A1, and the inverting input terminal of the operational amplifier A1 is represented by the symbol “-”; the second input terminal of the operational amplifier A1 is the non-inverting input terminal of the operational amplifier A1, and the non-inverting input terminal of the operational amplifier A1 is represented by the symbol “+”. The output terminal of the operational amplifier A1 is connected to the control electrode of the switching transistor T0. The second terminal of the first resistor R1 is connected to the first electrode of the switching transistor T0, and the second electrode of the switching transistor T0 is used to be connected to the second voltage terminal V2.

When the voltage regulating unit 230 is working, if the voltage at the non-inverting input terminal of the operational amplifier A1 is greater than the voltage at the inverting input terminal of the operational amplifier A1, it means that the current flowing through the first transistor T1 is too small. At this time, the operational amplifier A1 will output a high-level signal, thereby increasing the conduction degree of the switch transistor T0, that is, increasing the current flowing through the first transistor T1, so that the voltage at the non-inverting input terminal of the operational amplifier A1 can be reduced until the voltage at the non-inverting input terminal of the operational amplifier A1 is equal to the voltage at the inverting input terminal of the operational amplifier A1. On the contrary, when the voltage at the non-inverting input terminal of the operational amplifier A1 is less than the voltage at the inverting input terminal of the operational amplifier A1, it means that the current flowing through the first transistor T1 is too large. At this time, the operational amplifier A1 will output a low-level signal, thereby reducing the conduction degree of the switch transistor T0, that is, reducing the current flowing through the first transistor T1, so that the voltage at the non-inverting input terminal of the operational amplifier A1 can be increased until the voltage at the non-inverting input terminal of the operational amplifier A1 is equal to the voltage at the inverting input terminal of the operational amplifier A1.

In this embodiment, the processing unit 240 further has an output terminal d1 and an output terminal d2. The output terminal d1 of the processing unit 240 is connected to the control electrode of the first transistor T1 (the connection relationship is not shown in the figure). When the current detection circuit 20 is working, the output terminal d1 of the processing unit 240 can output a level signal, thereby controlling the first transistor T1 in the second shunt unit 220 to be turned on. The output terminal d2 of the processing unit 240 is connected to the control electrode of each of the multiple transistors in the first shunt unit 210 (the connection relationship is not shown in the figure). When the current detection circuit 20 is working, the output terminal d2 of the processing unit 240 can output a level signal, thereby controlling all transistors in the first shunt unit 210 to be turned on.

It can be seen from the above description that when the current detection circuit 20 is working, the target ratio is:

For any transistor, the resistance between the first and second terminals is: Wherein, _RT is the resistance between the first electrode and the second electrode of the transistor, μ is the carrier mobility of the channel of the transistor, Cox is the gate capacitance per unit area of the transistor, W is the channel width of the transistor, L is the channel length of the transistor, _VGS is the voltage difference between the control electrode and the first electrode of the transistor, and _VTH is the turn-on voltage of the transistor. In the embodiment of the present application, all transistors can be formed on the same silicon wafer, so that the carrier mobility, turn-on voltage, etc. of each transistor are basically the same. In this case, the gate capacitance per unit area of all transistors in the first shunt unit 210 and the second shunt unit 220 is controlled to be the same, and the voltage difference between the control electrode and the first electrode of all transistors in the first shunt unit 210 and the second shunt unit 220 is the same when the current detection circuit 20 is working, so that the target ratio is only related to the ratio of the channel width to the channel length of each transistor.

Combination and It can be obtained that, in the embodiment shown in FIG6 , when the ratio of the channel width to the channel length of all transistors in the first shunt unit 210 and the second shunt unit 220 is the same, the target ratio is 10. In this embodiment, since the target ratio is a fixed value, the target ratio can be pre-stored in the processing unit 240, so that the processing unit 240 determines the current of the load 30 according to the voltage of the first resistor R1 and the target ratio.

In this possible situation, in some embodiments not shown, the second shunt unit 220 may also include a plurality of transistors connected in parallel. When the current detection circuit 20 is working, all the transistors in the second shunt unit 220 are turned on, which will not be described in detail. In other embodiments not shown, each transistor in the first shunt unit 210 and the second shunt unit 220 may also be connected in series with a resistor of a fixed resistance, or each transistor in the first shunt unit 210 and the second shunt unit 220 may also be replaced with a resistor of a fixed resistance.

(2) In the second possible case, the target ratio is a non-constant value.

Fig. 7 is a circuit diagram of another current detection circuit 20 provided in an embodiment of the present application. In the embodiment shown in Fig. 7, the structures of the first shunt unit 210, the second shunt unit 220, and the voltage adjustment unit 230 are the same as those in the embodiment shown in Fig. 6, and will not be described in detail.

Different from the embodiment shown in FIG. 6 , in the embodiment shown in FIG. 7 , the processing unit 240 has a plurality of output terminals. The number of output terminals of the processing unit 240 is equal to the sum of the number of transistors in the first shunt unit 210 and the second shunt unit 220. Specifically, the processing unit 240 has an output terminal d1, an output terminal d2, an output terminal d3, an output terminal d4, and an output terminal d11. Among them, the output terminal d1 of the processing unit 240 is connected to the control electrode of the first transistor T1 (the connection relationship is not shown in the figure); the output terminal d2 of the processing unit 240 is connected to the control electrode of the second transistor T2; the output terminal d3 of the processing unit 240 is connected to the control electrode of the third transistor T3; the output terminal d4 of the processing unit 240 is connected to the control electrode of the fourth transistor T4, and the output terminal d11 of the processing unit 240 is connected to the control electrode of the eleventh transistor T11. In this way, the processing unit 240 can control the conduction and disconnection of each of the plurality of transistors in the first shunt unit 210. When the processing unit 240 is working, the output terminal d1 of the processing unit 240 can output a level signal, thereby controlling the first transistor T1 in the second shunt unit 220 to be turned on. At least one of the output terminals d2, d3, d4, ..., d11 of the processing unit 240 outputs a level signal, thereby controlling at least one of the second transistor T2, the third transistor T3, the fourth transistor T4, ..., the eleventh transistor T11 in the first shunt unit 210 to be turned on.

In this embodiment, when the processing unit 240 is working, the target ratio can be determined according to the number of transistors in the first shunt unit 210 that are in the on state. Still taking the case that the ratio of the channel width to the channel length of all transistors in the first shunt unit 210 and the second shunt unit 220 is the same, then: when two transistors in the first shunt unit 210 are turned on, the target ratio is 2; when three transistors in the first shunt unit 210 are turned on, the target ratio is 3... When ten transistors in the first shunt unit 210 are turned on, the target ratio is 10.

In this embodiment, the processing unit 240 is used to adjust the number of transistors in the first shunt unit 210 that are in the on state according to the voltage of the first resistor R1. By adjusting the number of transistors in the first shunt unit 210 that are in the on state, the target ratio can be adjusted.

The processing unit 240 can adjust the number of transistors in the on state among the multiple transistors in the first shunt unit 210, that is, by adjusting the target ratio, so that the voltage of the first resistor R1 is maintained within a preset voltage range. Specifically, a preset voltage range can be pre-set in the processing unit 240, and the preset voltage range is the target voltage range of the first resistor R1. That is, when the current detection circuit 20 is working, it is necessary to control the voltage of the first resistor R1 within the preset voltage range. When the processing unit 240 is working, it is used to: when the voltage of the first resistor R1 detected by the processing unit 240 is large, it indicates that the current flowing through the first resistor R1 is large, that is, the current flowing through the first shunt unit 210 is large. In this case, when the current flowing through the first shunt unit 210 remains unchanged, the processing unit 240 can increase the target ratio by increasing the number of transistors in the on state in the first shunt unit 210, thereby reducing the current flowing through the first resistor R1, that is, reducing the voltage of the first resistor R1, so that the voltage of the first resistor R1 is maintained within the preset voltage range. In this way, on the one hand, the current detection accuracy can be guaranteed, and on the other hand, the power loss caused by the sampling resistor can be reduced. Similarly, when the voltage of the first resistor R1 detected by the processing unit 240 is small, it indicates that the current flowing through the first resistor R1 is small, that is, the current flowing through the first shunt unit 210 is small. In this case, while the current flowing through the first shunt unit 210 remains unchanged, the processing unit 240 can reduce the target ratio by reducing the number of transistors in the on state in the first shunt unit 210, thereby increasing the current flowing through the first resistor R1, that is, increasing the voltage of the first resistor R1, so that the voltage of the first resistor R1 is maintained within the preset voltage range. In this way, the current detection accuracy can be guaranteed.

In this possible situation, in some embodiments not shown, at least two transistors among the plurality of transistors in the first shunt unit 210 may have different ratios of channel width to channel length.

(3) In the third possible case, the target ratio is a non-constant value.

FIG8 is a circuit diagram of another current detection circuit 20 provided in an embodiment of the present application. Different from the embodiment shown in FIG7, in the embodiment shown in FIG8, the second shunt unit 220 includes a twelfth transistor T12 and a thirteenth transistor T13 in addition to the first transistor T1. The first electrodes of the first transistor T1, the twelfth transistor T12, and the thirteenth transistor T13 are connected together to form a first end of the second shunt unit 220; the second electrodes of the first transistor T1, the twelfth transistor T12, and the thirteenth transistor T13 are connected together to form a second end of the second shunt unit 220. The processing unit 240 also has output terminals d12 and d13. The output terminal d12 of the processing unit 240 is connected to the control electrode of the twelfth transistor T12, and the output terminal d13 of the processing unit 240 is connected to the control electrode of the thirteenth transistor T13. In this embodiment, the processing unit 240 is used to adjust the target ratio by adjusting the number of transistors in the first shunt unit 210 that are in a conducting state, or/and by adjusting the number of transistors in the second shunt unit 220 that are in a conducting state. In this way, the adjustment range of the target ratio can be increased.

In this embodiment, when the processing unit 240 is working, it is used to determine the target ratio according to the number of transistors in the first shunt unit 210 that are in the on state and the number of transistors in the second shunt unit 220 that are in the on state.

The current detection circuit 20 provided in the embodiment of the present application is explained in detail from three possible implementations. In the following three possible implementations, the structures of each electrical unit (including the first shunt unit 210, the second shunt unit 220, the voltage adjustment unit, and the processing unit 240) are all taken as an example of the structure described in the above-mentioned "second possible situation"; the second voltage terminal V2 is the ground line GND.

In a first possible implementation, a circuit diagram of the current detection circuit 20 is shown in FIG7 . In this case, the second current path does not include the load 30 , that is, the second current dividing unit 220 is connected in parallel with the load 30 .

Specifically, the first end of the first shunt unit 210 is used to be connected to the first voltage terminal V1, the second end of the first shunt unit 210 is used to be connected to the first end of the load 30, and the second end of the load 30 is connected to the ground line GND. The first end of the second shunt unit 220 is connected to the first end of the first shunt unit 210. The first end of the first resistor R1 is connected to the second end of the second shunt unit 220, and the second end of the first resistor R1 is used to be connected to the second end of the load 30. The second end of the first shunt unit 210 is connected to the first end a of the voltage regulating unit 230, and the second end of the second shunt unit 220 is connected to the second end b of the voltage regulating unit 230.

Among them, the second shunt unit 220 includes a first transistor T1. The first shunt unit 210 includes a second transistor T2, a third transistor T3, a fourth transistor T4...an eleventh transistor T11. The first transistor T1, the second transistor T2, the third transistor T3, the fourth transistor T4...an eleventh transistor T11 are all P-type MOSFETs. The voltage regulating unit 230 includes an operational amplifier A1 and a switching transistor T0. The inverting input terminal of the operational amplifier A1 is connected to the second end of the first shunt unit 210. The non-inverting input terminal of the operational amplifier A1 is connected to the second end of the second shunt unit 220 and the first end of the first resistor R1. The output terminal of the operational amplifier A1 is connected to the control electrode of the switching transistor T0. The second end of the first resistor R1 is connected to the first electrode of the switching transistor T0, and the second electrode of the switching transistor T0 is connected to the second end of the load 30. That is, the first resistor R1 is connected to the second end of the load 30 through the switching transistor T0. The switching transistor T0 is an N-type MOSFET.

When the current detection circuit 20 is working, the current flows out from the first voltage terminal V1, flows into the ground line GND through the transistor in the first shunt unit 210 that is in the on state and the load 30, and forms a first current path. The current also flows out from the first voltage terminal V1, flows into the ground line GND through the second shunt unit 220, the first resistor R1, and the switch transistor T0, and forms a second current path.

When the voltage regulating unit 230 is working, if the voltage at the non-inverting input terminal of the operational amplifier A1 is greater than the voltage at the inverting input terminal of the operational amplifier A1, it means that the current flowing through the first transistor T1 is too small. At this time, the operational amplifier A1 will output a high-level signal, thereby increasing the conduction degree of the switch transistor T0, that is, increasing the current flowing through the first transistor T1, so that the voltage at the non-inverting input terminal of the operational amplifier A1 can be reduced until the voltage at the non-inverting input terminal of the operational amplifier A1 is equal to the voltage at the inverting input terminal of the operational amplifier A1. On the contrary, when the voltage at the non-inverting input terminal of the operational amplifier A1 is less than the voltage at the inverting input terminal of the operational amplifier A1, it means that the current flowing through the first transistor T1 is too large. At this time, the operational amplifier A1 will output a low-level signal, thereby reducing the conduction degree of the switch transistor T0, that is, reducing the current flowing through the first transistor T1, so that the voltage at the non-inverting input terminal of the operational amplifier A1 can be increased until the voltage at the non-inverting input terminal of the operational amplifier A1 is equal to the voltage at the inverting input terminal of the operational amplifier A1.

A preset voltage range may be set in the processing unit 240. The processing unit 240 is used to detect the voltage of the first resistor R1 when it is working. The processing unit 240 is also used to: if the detected voltage of the first resistor R1 is greater than the preset voltage range, adjust the number of transistors in the first shunt unit 210 that are in the on state by one, and detect the voltage of the first resistor R1 again until the voltage of the first resistor R1 is within the preset voltage range. At this time, the processing unit 240 can determine the target ratio according to the number of transistors in the first shunt unit 210 that are in the on state.

In this embodiment, when the processing unit 240 determines the current of the load 30 according to the voltage of the first resistor R1 and the target ratio, specifically:

The current of the first resistor R1 is determined according to the voltage of the first resistor R1 and the resistance value of the first resistor R1, that is, And, the current of the first resistor R1 is multiplied by the target ratio to obtain the current of the load 30 , that is, I _load =I _a =I _b ×K=I _R1 ×K.

In this embodiment, the voltage of the first resistor R1 detected by the processing unit 240 is also the voltage of the load 30 .

In a second possible implementation, a circuit diagram of the current detection circuit 20 is shown in FIG9 . In this case, the second current path includes a load 30 , that is, the second current dividing unit 220 and the load 30 are connected in series.

Specifically, the first end of the first shunt unit 210 is used to be connected to the first voltage terminal V1, the second end of the first shunt unit 210 is used to be connected to the first end of the load 30, and the second end of the load 30 is connected to the ground line GND. The first end of the second shunt unit 220 is connected to the first end of the first shunt unit 210. The first end of the first resistor R1 is connected to the second end of the second shunt unit 220, and the second end of the first resistor R1 is used to be connected to the first end of the load 30. The second end of the first shunt unit 210 is connected to the first end a of the voltage regulating unit 230, and the second end of the second shunt unit 220 is connected to the second end b of the voltage regulating unit 230.

Among them, the second shunt unit 220 includes a first transistor T1. The first shunt unit 210 includes a second transistor T2, a third transistor T3, a fourth transistor T4...an eleventh transistor T11. The first transistor T1, the second transistor T2, the third transistor T3, the fourth transistor T4...an eleventh transistor T11 are all P-type MOSFETs. The voltage regulating unit 230 includes an operational amplifier A1 and a switching transistor T0. The inverting input terminal of the operational amplifier A1 is connected to the second end of the first shunt unit 210. The non-inverting input terminal of the operational amplifier A1 is connected to the second end of the second shunt unit 220 and the first end of the first resistor R1. The output terminal of the operational amplifier A1 is connected to the control electrode of the switching transistor T0. The second end of the first resistor R1 is connected to the first electrode of the switching transistor T0, and the second electrode of the switching transistor T0 is connected to the first end of the load 30. That is, the first resistor R1 is connected to the first end of the load 30 through the switching transistor T0. The switching transistor T0 is an N-type MOSFET.

When the current detection circuit 20 is working, the current flows out from the first voltage terminal V1, flows into the ground line GND through the transistor in the on state in the first shunt unit 210 and the load 30, and forms a first current path. The current also flows out from the first voltage terminal V1, flows into the ground line GND through the second shunt unit 220, the first resistor R1, the switch transistor T0, and the load 30, and forms a second current path.

When the voltage regulating unit 230 is working, if the voltage at the non-inverting input terminal of the operational amplifier A1 is greater than the voltage at the inverting input terminal of the operational amplifier A1, it means that the current flowing through the first transistor T1 is too small. At this time, the operational amplifier A1 will output a high-level signal, thereby increasing the conduction degree of the switch transistor T0, that is, increasing the current flowing through the first transistor T1, so that the voltage at the non-inverting input terminal of the operational amplifier A1 can be reduced until the voltage at the non-inverting input terminal of the operational amplifier A1 is equal to the voltage at the inverting input terminal of the operational amplifier A1. On the contrary, when the voltage at the non-inverting input terminal of the operational amplifier A1 is less than the voltage at the inverting input terminal of the operational amplifier A1, it means that the current flowing through the first transistor T1 is too large. At this time, the operational amplifier A1 will output a low-level signal, thereby reducing the conduction degree of the switch transistor T0, that is, reducing the current flowing through the first transistor T1, so that the voltage at the non-inverting input terminal of the operational amplifier A1 can be increased until the voltage at the non-inverting input terminal of the operational amplifier A1 is equal to the voltage at the inverting input terminal of the operational amplifier A1.

A preset voltage range may be set in the processing unit 240. The processing unit 240 is used to detect the voltage of the first resistor R1 when it is working. The processing unit 240 is also used to: if the detected voltage of the first resistor R1 is greater than the preset voltage range, adjust the number of transistors in the first shunt unit 210 that are in the on state by one, and detect the voltage of the first resistor R1 again until the voltage of the first resistor R1 is within the preset voltage range. At this time, the processing unit 240 can determine the target ratio according to the number of transistors in the first shunt unit 210 that are in the on state.

In this embodiment, when the processing unit 240 determines the current of the load 30 according to the voltage of the first resistor R1 and the target ratio, specifically:

The current of the first resistor R1 is determined according to the voltage of the first resistor R1 and the resistance value of the first resistor R1, that is, And, the current of the load 30 is obtained by multiplying the current of the first resistor R1 by the sum of the target ratio plus one, that is, I _load =I _a +I _b =I _b ×K+I _b =I _b (K+1) =I _R1 (K+1).

In this embodiment, the voltage of the first resistor R1 detected by the processing unit 240 is also the voltage of the load 30 .

In this possible implementation, in some other embodiments not shown, the second shunt unit 220 may also include a plurality of transistors, each of the plurality of transistors is independently controlled by the processing unit 240, which will not be described in detail.

In a third possible implementation, a circuit diagram of the current detection circuit 20 is shown in FIG10 . In this case, the second current path includes a load 30 , that is, the second current dividing unit 220 and the load 30 are connected in series.

Specifically, the first end of the load 30 is used to be connected to the first voltage terminal V1, the first end of the first shunt unit 210 is used to be connected to the second end of the load 30, and the second end of the first shunt unit 210 is used to be connected to the ground line GND. The first end of the second shunt unit 220 is connected to the first end of the first shunt unit 210. The first end of the first resistor R1 is connected to the second end of the second shunt unit 220, and the second end of the first resistor R1 is used to be connected to the ground line GND. In this embodiment, due to the action of the voltage regulating unit 230, the voltage of the second end of the second shunt unit 220 is equal to the voltage of the second end of the first shunt unit 210, that is, the voltage of the first end of the first resistor R1 is equal to the voltage of the second end of the first shunt unit 210. Therefore, in order to avoid the voltage of the first end of the first resistor R1 being equal to the voltage of the second end of the first resistor R1, as shown in FIG10, the current detection circuit 20 further includes a second resistor R2, and the second end of the first shunt unit 210 is connected to the ground line GND through the second resistor R2.

Among them, the second shunt unit 220 includes a first transistor T1. The first shunt unit 210 includes a second transistor T2, a third transistor T3, a fourth transistor T4...an eleventh transistor T11. The first transistor T1, the second transistor T2, the third transistor T3, the fourth transistor T4...an eleventh transistor T11 are all N-type MOSFETs. The voltage regulating unit 230 includes an operational amplifier A1 and a switching transistor T0. The non-inverting input terminal of the operational amplifier A1 is connected to the second end of the first shunt unit 210. The inverting input terminal of the operational amplifier A1 is connected to the second end of the second shunt unit 220 and the first end of the first resistor R1. The output terminal of the operational amplifier A1 is connected to the control electrode of the switching transistor T0. The second end of the first resistor R1 is connected to the first electrode of the switching transistor T0, and the second electrode of the switching transistor T0 is connected to the second end of the second resistor R2. That is, the first resistor R1 is connected to the ground line GND through the switching transistor T0. The switching transistor T0 is a P-type MOSFET.

When the current detection circuit 20 is working, the current flows out from the first voltage terminal V1, flows into the ground line GND through the load 30, the transistor in the first shunt unit 210 that is in the on state, and the second resistor R2, forming a first current path. The current also flows out from the first voltage terminal V1, flows into the ground line GND through the load 30, the second shunt unit 220, the first resistor R1, and the switch transistor T0, forming a second current path.

When the voltage regulating unit 230 is working, if the voltage at the inverting input terminal of the operational amplifier A1 is greater than the voltage at the non-inverting input terminal of the operational amplifier A1, it means that the current flowing through the first transistor T1 is too small. At this time, the operational amplifier A1 will output a low-level signal, thereby increasing the conduction degree of the switch transistor T0, that is, increasing the current flowing through the first transistor T1, so that the voltage at the inverting input terminal of the operational amplifier A1 can be reduced until the voltage at the inverting input terminal of the operational amplifier A1 is equal to the voltage at the non-inverting input terminal of the operational amplifier A1. On the contrary, when the voltage at the inverting input terminal of the operational amplifier A1 is less than the voltage at the non-inverting input terminal of the operational amplifier A1, it means that the current flowing through the first transistor T1 is too large. At this time, the operational amplifier A1 will output a high-level signal, thereby reducing the conduction degree of the switch transistor T0, that is, reducing the current flowing through the first transistor T1, so that the voltage at the inverting input terminal of the operational amplifier A1 can be increased until the voltage at the inverting input terminal of the operational amplifier A1 is equal to the voltage at the non-inverting input terminal of the operational amplifier A1.

A preset voltage range may be set in the processing unit 240. The processing unit 240 is used to detect the voltage of the first resistor R1 when it is working. The processing unit 240 is also used to: if the detected voltage of the first resistor R1 is greater than the preset voltage range, adjust the number of transistors in the first shunt unit 210 that are in the on state by one, and detect the voltage of the first resistor R1 again until the voltage of the first resistor R1 is within the preset voltage range. At this time, the processing unit 240 can determine the target ratio according to the number of transistors in the first shunt unit 210 that are in the on state.

In this embodiment, when the processing unit 240 determines the current of the load 30 according to the voltage of the first resistor R1 and the target ratio, specifically:

The current of the first resistor R1 is determined according to the voltage of the first resistor R1 and the resistance value of the first resistor R1, that is, And, the current of the load 30 is obtained by multiplying the current of the first resistor R1 by the sum of the target ratio plus one, that is, I _load =I _a +I _b =I _b ×K+I _b =I _b (K+1) =I _R1 (K+1).

In this possible implementation, in some other embodiments not shown, the second shunt unit 220 may also include a plurality of transistors, each of the plurality of transistors is independently controlled by the processing unit 240, which will not be described in detail.

Figure 11 is a voltage simulation diagram of a first transistor T1 and a first resistor R1 provided in an embodiment of the present application. Wherein, the horizontal axis is time, the unit is s (seconds); the vertical axis is voltage, the unit is V. Curve ① represents the voltage of the first transistor T1, and curve ② represents the voltage of the first resistor R1 detected by the processing unit 240. According to Figure 11, since the first transistor T1 is connected in series with the first resistor R1, the current of the first transistor T1 is equal to the current of the first resistor R1. In this case, because the channel resistance of the first transistor T1 is small and the voltage is also small, it is difficult to measure accurately, so the current of the first resistor R1 can be obtained by measuring the voltage of the first resistor R1 with a larger resistance, that is, the current of the first transistor T1. In this way, the current detection accuracy can be improved.

The current detection circuit 20 provided in the embodiment of the present application has at least the following beneficial effects:

The current detection circuit 20 includes a first shunt unit 210, a second shunt unit 220, a voltage regulating unit 230, a first resistor R1 and a processing unit 240, and the current path formed includes a first current path and a second current path. The first current path includes the first shunt unit 210 and the load 30 connected in series, and the second current path includes the second shunt unit 220 and the first resistor R1 connected in series. The first resistor R1 is a sampling resistor. The voltage regulating unit 230 is used to make the voltage across the first shunt unit 210 the same as the voltage across the second shunt unit 220, so that the current of the first shunt unit 210 and the current of the second shunt unit 220 have a target ratio when the current detection circuit 20 is working. When the processing unit 240 is working, the current of the first resistor R1 can be determined according to the voltage of the first resistor R1, and then the current of the load 30 can be determined according to the current of the first resistor R1 and the target ratio, so as to achieve the purpose of current detection. Here, when the second current path does not include the load 30, that is, when the second shunt unit 220 is connected in parallel with the load 30, the target ratio is greater than 1. At this time, the current of the second shunt unit 220 is equal to the current of the first resistor R1, and is less than the current of the first shunt unit 210, that is, less than the current of the load 30. When the second current path includes the load 30, that is, the second shunt unit 220 is connected in series with the load 30, the target ratio is greater than 0. At this time, the current of the load 30 is equal to the current of the first shunt unit 210 plus the current of the second shunt unit 220, so the current of the second shunt unit 220 is also equal to the current of the first resistor R1, and is less than the current of the load 30. In this way, the power loss caused by the sampling resistor can be reduced by making the current of the sampling resistor less than the current of the load 30 while ensuring the detection accuracy of the current detection circuit 20, thereby improving the endurance of the electronic device.

The processing unit 240 can adjust the number of transistors in the first shunt unit 210 that are in the on state according to the voltage of the first resistor R1, and determine the target ratio according to the number of transistors in the first shunt unit 210 that are in the on state. In this way, no matter whether the current of the load 30 is large or small, the voltage of the first resistor R1 can be kept within the preset voltage range, so that the current detection accuracy can be guaranteed on the one hand, and the power loss caused by the sampling resistor can be reduced on the other hand.

An embodiment of the present application further provides a current detector, comprising a current detection circuit 20 as in any one of the above embodiments.

Specifically, the current detection circuit 20 includes a first shunt unit 210 , a second shunt unit 220 , a voltage adjustment unit 230 , a first resistor R1 , and a processing unit 240 .

The first shunt unit 210 is used to be connected in series with the load 30 between the first voltage terminal V1 and the second voltage terminal V2. The voltage of the first voltage terminal V1 is greater than the voltage of the second voltage terminal V2, so as to form a first current path from the first voltage terminal V1 to the second voltage terminal V2 via the first shunt unit 210 and the load 30. In some specific embodiments, the second voltage terminal V2 may be a ground line GND.

The first end of the second shunt unit 220 is connected to the first end of the first shunt unit 210, so that the voltage of the first end of the second shunt unit 220 is equal to the voltage of the first end of the first shunt unit 210. The second end of the first shunt unit 210 is connected to the first end a of the voltage regulating unit 230, and the second end of the second shunt unit 220 is connected to the second end b of the voltage regulating unit 230. When the current detection circuit 20 is working, the voltage of the first end a and the second end of the voltage regulating unit 230 are the same, that is, the voltage of the second end of the first shunt unit 210 is equal to the voltage of the second end of the second shunt unit 220.

The first resistor R1 is connected between the second end of the second shunt unit 220 and the second voltage end V2 to form a second current path starting from the first voltage end V1, passing through the second shunt unit 220 and the first resistor R1 to reach the second voltage end V2. The second current path may also further include a load 30. The processing unit 240 is connected to the first resistor R1 to detect the voltage of the first resistor R1. When the processing unit 240 is working, it is used to: determine the current of the load 30 according to the voltage of the first resistor R1 and the target ratio. The target ratio is the ratio of the current of the first shunt unit 210 to the current of the second shunt unit 220 when the current detection circuit 20 is working. When the second shunt unit 220 is connected in parallel with the load 30, that is, when the second current path does not include the load 30, the target ratio is greater than 1; when the second shunt unit 220 is connected in series with the load 30, that is, when the second circuit path includes the load 30, the target ratio is greater than 0.

In some embodiments, the first shunt unit 210 includes a plurality of transistors. The first electrodes of the plurality of transistors are connected to the first end of the second shunt unit 220. The second electrodes of the plurality of transistors are connected to the first end a of the voltage regulating unit 230. The processing unit 240 has a plurality of output terminals, and the plurality of output terminals of the processing unit 240 are connected to the control electrodes of the plurality of transistors one by one to control the on and off of each transistor in the plurality of transistors. The processing unit 240 is further used to determine the target ratio according to the number of transistors in the on state in the plurality of transistors.

Further, the processing unit 240 is also used to: adjust the number of transistors in the on state among the multiple transistors according to the voltage of the first resistor R1. That is, in this embodiment, the processing unit 240 can adjust the number of transistors in the on state among the multiple transistors of the first shunt unit 210 according to the voltage of the first resistor R1, thereby adjusting the ratio of the current of the first shunt unit 210 to the current of the second shunt unit 220. Specifically, a preset voltage range can be provided in the processing unit 240. When the processing unit 240 is working, it is used to: if the voltage of the first resistor R1 is greater than the maximum value of the preset voltage range, increase the number of transistors in the on state among the multiple transistors of the first shunt unit 210, so that the voltage of the first resistor R1 is within the preset voltage range. And, if the voltage of the first resistor R1 is less than the minimum value of the preset voltage range, reduce the number of transistors in the on state among the multiple transistors of the first shunt unit 210, so that the voltage of the first resistor R1 is within the preset voltage range. In this way, no matter the current of the load 30 is large or small, the voltage of the first resistor R1 can be kept within the preset voltage range, thereby ensuring the current detection accuracy on the one hand and reducing the power loss caused by the sampling resistor on the other hand.

In some specific embodiments, the ratio of the channel width to the channel length of each transistor in the plurality of transistors in the first current splitting unit 210 is equal.

In some embodiments, the second shunt unit 220 includes a first transistor T1. A first electrode of the first transistor T1 is connected to a first end of the first shunt unit 210, and a second electrode of the first transistor T1 is connected to a second end b of the voltage regulating unit 230. When the current detection circuit 20 is working, the first transistor T1 is turned on.

In some embodiments, the voltage regulating unit 230 includes: an operational amplifier A1 and a switch transistor T0. The first input terminal of the operational amplifier A1 is connected to the second terminal of the first shunt unit 210, the second input terminal of the operational amplifier A1 is connected to the second terminal of the second shunt unit 220 and the first terminal of the first resistor R1, and the output terminal of the operational amplifier A1 is connected to the control electrode of the switch transistor T0. The second terminal of the first resistor R1 is connected to the first electrode of the switch transistor T0, and the second electrode of the switch transistor T0 is used to be connected to the second voltage terminal V2.

The current detection circuit 20 provided in the present application is explained below from three possible implementation modes.

In a first possible implementation, the first end of the first shunt unit 210 is used to connect to the first voltage terminal V1, the second end of the first shunt unit 210 is used to connect to the first end of the load 30, and the second end of the load 30 is connected to the second voltage terminal V2. The first end of the first resistor R1 is connected to the second end of the second shunt unit 220, and the second end of the first resistor R1 is used to connect to the second end of the load 30. In this case, the second current path does not include the load 30, that is, the second shunt unit 220 is connected in parallel with the load 30. At this time, the processing unit 240 is used to: determine the current of the first resistor R1 according to the voltage of the first resistor R1 and the resistance value of the first resistor R1; multiply the current of the first resistor R1 by the target ratio to obtain the current of the load 30.

In a second possible implementation, the first end of the first shunt unit 210 is used to connect to the first voltage terminal V1, the second end of the first shunt unit 210 is used to connect to the first end of the load 30, and the second end of the load 30 is connected to the second voltage terminal V2. The first end of the first resistor R1 is connected to the second end of the second shunt unit 220, and the second end of the first resistor R1 is used to connect to the first end of the load 30. In this case, the second current path includes the load 30, that is, the second shunt unit 220 is connected in series with the load 30. At this time, the processing unit 240 is used to: determine the current of the first resistor R1 according to the voltage of the first resistor R1 and the resistance value of the first resistor R1. The product of the current of the first resistor R1 and K+1 is determined as the current of the load 30, and K is the target ratio.

In a third possible implementation, the current detection circuit 20 further includes: a second resistor R2. The first end of the load 30 is used to be connected to the first voltage terminal V1, the first end of the first shunt unit 210 is used to be connected to the second end of the load 30, the second end of the first shunt unit 210 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is used to be connected to the second voltage terminal V2. The first end of the first resistor R1 is connected to the second end of the second shunt unit 220, and the second end of the first resistor R1 is connected to the second end of the second resistor R2. In this case, the second current path includes the load 30, that is, the second shunt unit 220 is connected in series with the load 30. At this time, the processing unit 240 is used to: determine the current of the first resistor R1 according to the voltage of the first resistor R1 and the resistance value of the first resistor R1. The product of the current of the first resistor R1 and K+1 is determined as the current of the load 30, and K is the target ratio.

An embodiment of the present application further provides an electronic device, including a load 30 and a current detection circuit 20 or a current detector as in any one of the above embodiments.

The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims (12)

1. A current detection circuit, characterized in that it comprises: a first shunt unit, a second shunt unit, a voltage adjustment unit, a first resistor and a processing unit; The first shunt unit is used to be connected in series with the load between the first voltage terminal and the second voltage terminal, and the voltage of the first voltage terminal is greater than the voltage of the second voltage terminal; the first end of the second shunt unit is connected to the first end of the first shunt unit; the second end of the first shunt unit is connected to the first end of the voltage regulating unit, and the second end of the second shunt unit is connected to the second end of the voltage regulating unit; when the current detection circuit is working, the voltage of the first end and the second end of the voltage regulating unit are the same; The first resistor is connected between the second end of the second shunt unit and the second voltage end; the processing unit is connected to the first resistor to detect the voltage of the first resistor, and the processing unit is used to: determine the current of the load according to the voltage of the first resistor and a target ratio, and the target ratio is the ratio of the current of the first shunt unit to the current of the second shunt unit when the current detection circuit is working; when the second shunt unit is connected in parallel with the load, the target ratio is greater than 1; when the second shunt unit is connected in series with the load, the target ratio is greater than 0. 2. The current detection circuit according to claim 1, characterized in that the first shunt unit comprises a plurality of transistors, the first electrodes of the plurality of transistors are all connected to the first end of the second shunt unit, and the second electrodes of the plurality of transistors are all connected to the first end of the voltage regulating unit; The processing unit has multiple output terminals, and the multiple output terminals of the processing unit are connected one-to-one with the control electrodes of the multiple transistors to control the conduction and shutdown of each of the multiple transistors; the processing unit is also used to: determine the target ratio according to the number of transistors in the on state among the multiple transistors. 3 . The current detection circuit according to claim 2 , wherein the processing unit is further configured to adjust the number of transistors in the on state among the plurality of transistors according to the voltage of the first resistor. 4. The current detection circuit as described in claim 3 is characterized in that the processing unit is used to: if the voltage of the first resistor is greater than the maximum value of the preset voltage range, increase the number of transistors in the on state among the multiple transistors so that the voltage of the first resistor is within the preset voltage range; if the voltage of the first resistor is less than the minimum value of the preset voltage range, reduce the number of transistors in the on state among the multiple transistors so that the voltage of the first resistor is within the preset voltage range. 5 . The current detection circuit according to claim 2 , wherein the ratio of the channel width to the channel length of each of the plurality of transistors is equal. 6. The current detection circuit as described in any one of claims 1 to 5 is characterized in that the second shunt unit includes a first transistor, a first electrode of the first transistor is connected to the first end of the first shunt unit, and a second electrode of the first transistor is connected to the second end of the voltage regulation unit; when the current detection circuit is working, the first transistor is turned on. 7. The current detection circuit according to any one of claims 1 to 6, characterized in that the voltage regulating unit comprises: an operational amplifier and a switching transistor; The first input end of the operational amplifier is connected to the second end of the first shunt unit, the second input end of the operational amplifier is connected to the second end of the second shunt unit and the first end of the first resistor, and the output end of the operational amplifier is connected to the control electrode of the switch transistor; The second end of the first resistor is connected to the first electrode of the switch transistor, and the second electrode of the switch transistor is used to be connected to the second voltage end. 8. The current detection circuit according to any one of claims 1 to 7, characterized in that the first end of the first shunt unit is used to connect to the first voltage end, the second end of the first shunt unit is used to connect to the first end of the load, and the second end of the load is connected to the second voltage end; the first end of the first resistor is connected to the second end of the second shunt unit, and the second end of the first resistor is used to connect to the second end of the load; The processing unit is used to: determine the current of the first resistor according to the voltage of the first resistor and the resistance value of the first resistor; and multiply the current of the first resistor by the target ratio to obtain the current of the load. 9. The current detection circuit according to any one of claims 1 to 7, characterized in that the first end of the first shunt unit is used to connect to the first voltage end, the second end of the first shunt unit is used to connect to the first end of the load, and the second end of the load is connected to the second voltage end; the first end of the first resistor is connected to the second end of the second shunt unit, and the second end of the first resistor is used to connect to the first end of the load; The processing unit is used to: determine the current of the first resistor according to the voltage of the first resistor and the resistance value of the first resistor; determine the product of the current of the first resistor and K+1 as the current of the load, where K is the target ratio. 10. The current detection circuit according to any one of claims 1 to 7, characterized in that the current detection circuit further comprises: a second resistor; the first end of the load is used to be connected to the first voltage end, the first end of the first shunt unit is used to be connected to the second end of the load, the second end of the first shunt unit is connected to the first end of the second resistor, and the second end of the second resistor is used to be connected to the second voltage end; the first end of the first resistor is connected to the second end of the second shunt unit, and the second end of the first resistor is connected to the second end of the second resistor; The processing unit is used to: determine the current of the first resistor according to the voltage of the first resistor and the resistance value of the first resistor; determine the product of the current of the first resistor and K+1 as the current of the load, where K is the target ratio. 11. A current detector, characterized by comprising the current detection circuit according to any one of claims 1 to 10. 12 . An electronic device, characterized by comprising the current detection circuit according to any one of claims 1 to 10 or the current detector according to claim 11 .