Bidirectional current detection circuit and electronic equipment

Abstract

The utility model relates to a bidirectional current detection circuit and electronic equipment, the circuit comprises a bias voltage providing circuit and a detection circuit, the output end of the bias voltage providing circuit is connected with the input end of the detection circuit, and the bias voltage providing circuit is used for providing bias voltage for the detection circuit; the detection circuit comprises a first resistor, a second resistor and a first operational amplifier, the non-inverting input end of the first operational amplifier is connected with the output end of the bias voltage supply circuit, the inverting input end of the first operational amplifier is connected with the first input end, and the inverting input end of the first operational amplifier is connected with one end of the first resistor; the other end of the first resistor is connected with the output end of the first operational amplifier, and the two ends of the second resistor are connected with the non-inverting input end and the inverting input end of the first operational amplifier respectively. According to the circuit connection mode, detection of the charging current and the discharging current can be achieved at the same time through the provided bias voltage.

Description

Technical Field

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

[0002] When the battery pack device is charging / discharging, in order to avoid damage to the battery pack device caused by large charging / discharging current, it is necessary to detect the charging / discharging current in time.

[0003] Currently, when detecting the charging / discharging current, two groups of operational amplifiers are usually used to detect the charging current and the discharging current respectively, which requires occupying two I / O ports. Utility Model Content

[0004] The present application provides a bidirectional current detection circuit and electronic device to simultaneously detect charging / discharging currents and implement current detection of a single I / O port.

[0005] In a first aspect, the present application provides a bidirectional current detection circuit, including a bias voltage providing circuit and a detection circuit.

[0006] The output end of the bias voltage providing circuit is connected to the input end of the detection circuit, and the bias voltage providing circuit is used to provide a bias voltage for the detection circuit;

[0007] The detection circuit includes a first resistor, a second resistor and a first operational amplifier, the non-inverting input terminal of the first operational amplifier is connected to the output terminal of the bias voltage providing circuit, the inverting input terminal of the first operational amplifier is connected to the first input terminal, the inverting input terminal of the first operational amplifier is connected to one end of the first resistor, the other end of the first resistor is connected to the output terminal of the first operational amplifier, and the two ends of the second resistor are respectively connected to the non-inverting input terminal and the inverting input terminal of the first operational amplifier. The detection circuit is used to detect the charging / discharging current of the first input terminal according to the bias voltage provided by the bias voltage providing circuit, and output the detection value at the output terminal of the detection circuit according to the charging / discharging current.

[0008] In a second aspect, the present application provides an electronic device, wherein the electronic device comprises the bidirectional current detection circuit described in any one of the above.

[0009] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0010] In the circuit provided by the embodiment of the present application, the bias voltage providing circuit generates a bias voltage and outputs the bias voltage to the detection circuit; the detection circuit detects the current of the first input terminal, when the current of the first input terminal is a charging current, there is a negative voltage between the first input terminal and the ground, under the action of the bias voltage, the first operational amplifier outputs a voltage value greater than 0 but less than the bias voltage at the output terminal; when the current of the first input terminal is a discharging current, there is a positive voltage between the first input terminal and the ground, under the action of the bias voltage, the first operational amplifier outputs a voltage value greater than the bias voltage at the output terminal; according to the value range of the output voltage value of the first operational amplifier at the output terminal, it can be determined whether the current detection is a charging current or a discharging current. At the same time, based on the connection mode of the first operational amplifier, the output voltage value of the first operational amplifier at the output terminal can be determined, which is specifically the bias voltage ± the amplification factor of the first operational amplifier × the voltage drop of the second resistor, so that the voltage drop of the second resistor can be determined, thereby determining the current size of the charging / discharging current, completing the detection of the bidirectional current, and realizing the current detection of a single I / O port. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0012] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0013] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0014] Figure 1 A circuit structure diagram of a bidirectional current detection circuit provided in an embodiment of the present application.

[0015] Figure 2 A connection diagram of a bidirectional current detection circuit provided in an embodiment of the present application.

[0016] Explanation of the accompanying drawings: 1. Bias voltage providing circuit; 2. Detection circuit; 3. Switching circuit; R1. First resistor; R2. Second resistor; R3. Third resistor; R4. Fourth resistor; R5. Fifth resistor; R6. Sixth resistor; R7. Seventh resistor; R8. Eighth resistor; R9. Ninth resistor; R10. Tenth resistor; C1. First capacitor; C2. Second capacitor; C3. Third capacitor; C4. Fourth capacitor; C5. Fifth capacitor; U1. First operational amplifier; U2. Second operational amplifier; Q1. PMOS tube; IN1. First input terminal; IN2. Second input terminal; IN3. Third input terminal; OUT1. First output terminal. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution 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. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0018] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0019] In order to solve the technical problem in the prior art that two groups of operational amplifiers are used to detect the charging current and the discharging current respectively, which requires occupying two I / O ports, the present application provides a bidirectional current detection circuit that can realize current detection of a single I / O port.

[0020] Reference Figure 1 and Figure 2 The present application provides a bidirectional current detection circuit, including a bias voltage providing circuit 1 and a detection circuit 2.

[0021] The output end of the bias voltage providing circuit 1 is connected to the input end of the detection circuit 2, and the bias voltage providing circuit 1 is used to provide a bias voltage for the detection circuit 2;

[0022] The detection circuit 2 includes a first resistor R1, a second resistor R2 and a first operational amplifier U1. The non-inverting input terminal of the first operational amplifier U1 is connected to the output terminal of the bias voltage providing circuit 1, the inverting input terminal of the first operational amplifier U1 is connected to the first input terminal IN1, the inverting input terminal of the first operational amplifier U1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to the output terminal of the first operational amplifier U1, and the two ends of the second resistor R2 are respectively connected to the non-inverting input terminal and the inverting input terminal of the first operational amplifier U1. The detection circuit 2 is used to detect the charging / discharging current of the first input terminal IN1 according to the bias voltage provided by the bias voltage providing circuit 1, and output the detection value at the output terminal of the detection circuit 2 according to the charging / discharging current.

[0023] Specifically, when there is a charge / discharge current between the first input terminal IN1 and the ground, a voltage drop is generated on the second resistor R2, and the voltage drop on the second resistor R2 is related to the size of the charge / discharge current. At the same time, the bias voltage providing circuit 1 provides a fixed bias voltage for the detection circuit 2.

[0024] The detection circuit 2 detects the charging / discharging current flowing in the loop between the first input terminal IN1 and the ground. When the current between the first input terminal IN1 and the ground is a charging current, there is a negative voltage between the first input terminal IN1 and the ground. Under the action of the bias voltage, the first operational amplifier U1 outputs an output voltage value greater than 0 but less than the bias voltage at the output terminal; when the current between the first input terminal IN1 and the ground is a discharging current, there is a positive voltage between the first input terminal IN1 and the ground. Under the action of the bias voltage, the first operational amplifier U1 outputs an output voltage value greater than the bias voltage at the output terminal. Based on the value range of the output voltage value of the first operational amplifier U1, it can be determined whether the current flowing in the loop between the first input terminal IN1 and the ground is a charging current or a discharging current.

[0025] At the same time, based on the connection mode of the first operational amplifier U1, the output voltage value of the first operational amplifier U1 is specifically: bias voltage ± amplification factor of the first operational amplifier U1 × voltage drop of the second resistor R2. When the current between the first input terminal IN1 and the ground is a discharge current, the output voltage value of the first operational amplifier U1 is specifically bias voltage + amplification factor of the first operational amplifier U1 × voltage drop of the second resistor R2; when the current between the first input terminal IN1 and the ground is a charging current, the output voltage value of the first operational amplifier U1 is specifically bias voltage - amplification factor of the first operational amplifier U1 × voltage drop of the second resistor R2. On the basis of being able to determine the output voltage value of the first operational amplifier U1, the voltage drop of the second resistor R2 can be determined. If the voltage drop of the second resistor R2 and the resistance value of the second resistor R2 are known, the specific current value of the charging / discharging current flowing in the loop between the first input terminal IN1 and the ground detected by the detection circuit 2 can be determined, and the detection of the bidirectional current can be completed.

[0026] In a feasible embodiment of the present application, the model of the first operational amplifier U1 may be LM258DRG3.

[0027] In a feasible embodiment of the present application, the bidirectional current detection circuit 2 also includes a switching circuit 3, one end of the switching circuit 3 is connected to the second input terminal IN2, the other end of the switching circuit 3 is connected to the third input terminal IN3, the output end of the switching circuit 3 is connected to the input end of the bias voltage providing circuit 1, and the switching circuit 3 is used to turn on or off the bias voltage providing circuit 1 and the detection circuit 2 according to the input voltage of the second input terminal IN2 and the input voltage of the third input terminal IN3.

[0028] The switch circuit 3 includes a third resistor R3, a fourth resistor R4 and a PMOS tube Q1. The two ends of the third resistor R3 are respectively connected to the source and the gate of the PMOS tube Q1, so that the source voltage and the gate voltage of the PMOS tube Q1 are equal. The gate of the PMOS tube Q1 is connected to the second input terminal IN2, the source of the PMOS tube Q1 is connected to the third input terminal IN3, the drain of the PMOS tube Q1 is the output end of the switch circuit 3, one end of the fourth resistor R4 is connected to the second input terminal IN2, and the other end of the fourth resistor R4 is connected to the gate of the PMOS tube Q1.

[0029] Specifically, the third input terminal IN3 inputs a fixed voltage value to the switch circuit 3. When the voltage value input to the switch circuit 3 by the second input terminal IN2 is greater than or equal to the voltage value input to the switch circuit 3 by the third input terminal IN3, the source and drain of the PMOS tube Q1 are connected, thereby controlling the bias voltage providing circuit 1 and the detection circuit 2 to turn on.

[0030] In a feasible embodiment of the present application, the model of the PMOS tube Q1 may be LBSS84LT1, with a rated current of 130 mA.

[0031] In a feasible embodiment of the present application, the bias voltage providing circuit 1 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a second operational amplifier U2, one end of the fifth resistor R5 is connected to the output end of the switching circuit 3, the other end of the fifth resistor R5 is connected to one end of the sixth resistor R6, the other end of the sixth resistor R6 is grounded, the positive power input end of the second operational amplifier U2 is connected to one end of the fifth resistor R5, the in-phase input end of the second operational amplifier U2 is connected to the other end of the fifth resistor R5, the inverting input end of the second operational amplifier U2 is connected to the output end of the second operational amplifier U2, the negative power input end of the second operational amplifier U2 is grounded, one end of the seventh resistor R7 is connected to the output end of the second operational amplifier U2, and the other end of the seventh resistor R7 is the output end of the bias voltage providing circuit 1.

[0032] In a feasible embodiment of the present application, the bias voltage providing circuit 1 also includes a first capacitor C1 and a second capacitor C2, one end of the first capacitor C1 is grounded, and the other end of the first capacitor C1 is connected to the positive power input terminal of the second operational amplifier U2, one end of the second capacitor C2 is grounded, and the other end of the second capacitor C2 is connected to the positive power input terminal of the second operational amplifier U2.

[0033] Specifically, when the bias voltage providing circuit 1 is turned on, the second operational amplifier U2 forms a voltage follower through the above connection method, and the output voltage of the output terminal of the second operational amplifier U2 is the same as the input voltage of its in-phase input terminal. When the switch circuit 3 is turned on, the third input terminal IN3 of the switch circuit 3 provides an input voltage to the bias voltage providing circuit 1, which is input to the second operational amplifier U2 after being divided by the fifth resistor R5 and the sixth resistor R6.

[0034] The voltage value of the output voltage of the bias voltage providing circuit 1 through the second operational amplifier U2 is the voltage value of the bias voltage acting on the non-inverting input terminal of the first operational amplifier U1, and the specific value of the bias voltage is determined based on the resistance values ​​of the fifth resistor R5 and the sixth resistor R6. In a feasible embodiment of the present application, the resistance values ​​of the fifth resistor R5 and the sixth resistor R6 are the same, and the voltage value of the bias voltage is the input voltage value of the third input terminal IN3 / 2.

[0035] In a feasible embodiment of the present application, the model of the second operational amplifier U2 may be LM258DRG3.

[0036] In a feasible embodiment of the present application, the model of the first capacitor C1 and the second capacitor C2 may be 0402C. The capacitance value of the first capacitor C1 is 1 μF, and the capacitance value of the second capacitor C2 is 0.1 μF, thereby achieving absorption of noises of different frequencies.

[0037] In a feasible embodiment of the present application, the resistance values ​​of the fifth resistor R5 and the sixth resistor R6 are equal, then the output voltage of the output end of the second operational amplifier U2 is the input voltage of the third input end IN3 / 2, and the output voltage of the output end of the second operational amplifier U2 serves as the bias voltage of the first operational amplifier U1.

[0038] The seventh resistor R7 is connected to the output end of the second operational amplifier U2 to prevent the output current of the output end of the second operational amplifier U2 from being too large. The first capacitor C1 and the second capacitor C2 are used for filtering.

[0039] In a feasible embodiment of the present application, the detection circuit 2 also includes a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5, the two ends of the third capacitor C3 are respectively connected to the non-inverting input terminal and the inverting input terminal of the first operational amplifier U1, the two ends of the fourth capacitor C4 are respectively connected to the non-inverting input terminal and the inverting input terminal of the first operational amplifier U1, one end of the fifth capacitor C5 is grounded, and the other end of the fifth capacitor C5 is connected to the output terminal of the first operational amplifier U1.

[0040] The detection circuit 2 also includes an eighth resistor R8, a ninth resistor R9 and a tenth resistor R10, one end of the eighth resistor R8 is connected to the non-inverting input terminal of the second operational amplifier U2, the other end of the eighth resistor R8 is grounded, one end of the ninth resistor R9 is connected to the inverting input terminal of the second operational amplifier U2, the other end of the ninth resistor R9 is connected to the third input terminal IN3, one end of the tenth resistor R10 is connected to the output terminal of the second operational amplifier U2, and the other end of the tenth resistor R10 is connected to the output terminal of the detection circuit 2.

[0041] Specifically, the eighth resistor R8, the ninth resistor R9 and the tenth resistor R10 are used for current limiting, the third capacitor C3 and the fourth capacitor C4 are used for differential signal filtering, and the fifth capacitor C5 is used for output signal filtering of the first operational amplifier U1.

[0042] Through the circuit provided by the embodiment of the present application, the circuit provided by the embodiment of the present application, the bias voltage providing circuit 1 generates a bias voltage and outputs the bias voltage to the detection circuit 2; the detection circuit 2 detects the current of the first input terminal IN1, when the current of the first input terminal IN1 is a charging current, there is a negative voltage between the first input terminal IN1 and the ground, under the action of the bias voltage, the first operational amplifier U1 outputs a voltage value greater than 0 but less than the bias voltage at the output terminal; when the current of the first input terminal IN1 is a discharging current, there is a positive voltage between the first input terminal IN1 and the ground, under the action of the bias voltage, the first operational amplifier U1 outputs a voltage value greater than the bias voltage at the output terminal; according to the value range of the output voltage value of the first operational amplifier U1 at the output terminal, it can be determined whether the current detected is a charging current or a discharging current. At the same time, based on the connection method of the first operational amplifier U1, the output voltage value of the first operational amplifier U1 at the output end can be determined, which is specifically the bias voltage ± the amplification factor of the first operational amplifier U1 × the voltage drop of the second resistor R2, so that the voltage drop of the second resistor R2 can be determined, thereby determining the current size of the charging / discharging current, completing the detection of bidirectional current, and realizing current detection of a single I / O port.

[0043] In addition, the present application also provides an electronic device, which includes the bidirectional current detection circuit described in any one of the above.

[0044] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0045] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A bidirectional current detection circuit, It is characterized in that Including bias voltage supply circuit and detection circuit, The output end of the bias voltage providing circuit is connected to the input end of the detection circuit, and the bias voltage providing circuit is used to provide a bias voltage for the detection circuit; The detection circuit includes a first resistor, a second resistor and a first operational amplifier, the non-inverting input terminal of the first operational amplifier is connected to the output terminal of the bias voltage providing circuit, the inverting input terminal of the first operational amplifier is connected to the first input terminal, the inverting input terminal of the first operational amplifier is connected to one end of the first resistor, the other end of the first resistor is connected to the output terminal of the first operational amplifier, and the two ends of the second resistor are respectively connected to the non-inverting input terminal and the inverting input terminal of the first operational amplifier, and the detection circuit is used to detect the charging / discharging current of the first input terminal according to the bias voltage provided by the bias voltage providing circuit, and output the detection value at the output terminal of the detection circuit according to the charging / discharging current.

2. The circuit according to claim 1, It is characterized in that The circuit further comprises a switch circuit, One end of the switch circuit is connected to the second input end, the other end of the switch circuit is connected to the third input end, the output end of the switch circuit is connected to the input end of the bias voltage providing circuit, and the switch circuit is used to turn on or off the bias voltage providing circuit and the detection circuit according to the input voltage of the second input end and the input voltage of the third input end.

3. The circuit according to claim 2, It is characterized in that The switch circuit includes a third resistor and a PMOS tube. The two ends of the third resistor are respectively connected to the source and gate of the PMOS tube so that the source voltage and the gate voltage of the PMOS tube are equal, the gate of the PMOS tube is connected to the second input end, the source of the PMOS tube is connected to the third input end, and the drain of the PMOS tube is the output end of the switching circuit.

4. The circuit according to claim 3, It is characterized in that The switch circuit further includes a fourth resistor, One end of the fourth resistor is connected to the second input end, and the other end of the fourth resistor is connected to the gate of the PMOS tube.

5. The circuit according to claim 2, It is characterized in that The bias voltage providing circuit includes a fifth resistor, a sixth resistor and a second operational amplifier. One end of the fifth resistor is connected to the output end of the switching circuit, the other end of the fifth resistor is connected to one end of the sixth resistor, the other end of the sixth resistor is grounded, the positive power input end of the second operational amplifier is connected to one end of the fifth resistor, the non-inverting input end of the second operational amplifier is connected to the other end of the fifth resistor, the inverting input end of the second operational amplifier is connected to the output end of the second operational amplifier, and the negative power input end of the second operational amplifier is grounded.

6. The circuit according to claim 5, It is characterized in that The bias voltage providing circuit further includes a seventh resistor, One end of the seventh resistor is connected to the output end of the second operational amplifier, and the other end of the seventh resistor is the output end of the bias voltage providing circuit.

7. The circuit according to claim 5, It is characterized in that The bias voltage providing circuit also includes a first capacitor and a second capacitor. One end of the first capacitor is grounded, and the other end of the first capacitor is connected to the positive power input terminal of the second operational amplifier. One end of the second capacitor is grounded, and the other end of the second capacitor is connected to the positive power input terminal of the second operational amplifier.

8. The circuit according to claim 1, It is characterized in that The detection circuit further includes a third capacitor, a fourth capacitor and a fifth capacitor. The two ends of the third capacitor are respectively connected to the non-inverting input terminal and the inverting input terminal of the first operational amplifier, the two ends of the fourth capacitor are respectively connected to the non-inverting input terminal and the inverting input terminal of the first operational amplifier, one end of the fifth capacitor is grounded, and the other end of the fifth capacitor is connected to the output terminal of the first operational amplifier.

9. The circuit according to claim 5, It is characterized in that The detection circuit further includes an eighth resistor, a ninth resistor and a tenth resistor, One end of the eighth resistor is connected to the non-inverting input terminal of the second operational amplifier, the other end of the eighth resistor is grounded, one end of the ninth resistor is connected to the inverting input terminal of the second operational amplifier, the other end of the ninth resistor is connected to the third input terminal, one end of the tenth resistor is connected to the output terminal of the second operational amplifier, and the other end of the tenth resistor is connected to the output terminal of the detection circuit.

10. An electronic device, It is characterized in that The electronic device comprises the bidirectional current detection circuit according to any one of claims 1 to 9.

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