Bidirectional current detection circuit

Abstract

The invention discloses a bidirectional current detection circuit. The bidirectional current detection circuit comprises a first amplifying circuit, a second amplifying circuit, a first current mirror, a second current mirror, a third current mirror, a first switch circuit, a second switch circuit, a comparator Comp1, an amplifier Amp1, an inverter INV1 and resistors R1-R4; a resistor Rsen is arranged between a test access end Vin1 and a test access end Vin2; the test access end Vin1 is connected with an inversing input end of the comparator Comp1 through the resistor R1, and the test access end Vin2 is connected to a positive input end of the comparator Comp1 through the resistor R2; the output end of the comparator Comp1 is connected with the second switch circuit; the second switch circuit is used for controlling on and off of the first switch circuit; the bidirectional current detection circuit can detect the current size and the flow direction of current simultaneously.

Description

technical field [0001] The invention relates to the technical field of current detection, in particular to a bidirectional current detection circuit. Background technique [0002] Current sense amplifiers are widely used in welding equipment, computers, mobile phones, telecommunication equipment, automotive, power management, battery chargers, etc. By monitoring the magnitude and direction of current flow, motor torque, solenoid force, LED density, solar cell light exposure, battery charge, etc. can be best monitored. Therefore, a circuit is needed that can accurately measure the current and convert the current to a voltage, so that the voltage can be amplified, regulated, and measured with existing voltage devices (amplifiers, comparators, ADCs, etc.). In these applications, the amplifier in the current sense circuit is used to extract the small differential voltage generated by the current through the small sense resistor from the high common mode voltage, such as figure...

AI Technical Summary

Problems solved by technology

However, most of these current sense amplifier control chips generally do not have the ability to accept positive and negative polarity voltages. Therefore, an additional circuit is required to level shift the voltage, which increases the cost and complexity of the circuit. , on the other hand reduces the sampling accuracy

However, some current sense amplifier control chips can detect bidirectional current flow, but the application range is limited to the current flow between positive voltages.

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