current detection circuit

Abstract

A current detection circuit is disclosed, which can be used to detect the load current of an H bridge circuit. By controlling the two amplifiers to alternately detect the positive and negative voltages at both ends of the sense resistor, and one amplifier works in the signal amplifying state while the other amplifier works in the zero-adjusting state, which avoids the present situation while detecting the bidirectional current. With technology common mode interference, it provides accurate detection current signal.

Description

Technical field [0001] The embodiment of the present invention relates to an electronic circuit, and more particularly to a current detection circuit for detecting the load current of an H-bridge circuit. Background technique [0002] The H-bridge circuit uses a single power supply VIN to supply power, and is often used to drive motors or other bidirectional loads. figure 1 It is a simple schematic diagram of the H-bridge circuit. Such as figure 1 As shown, the switching tubes M1 and M4 constitute a first switching tube pair, and the switching tubes M2 and M3 constitute a second switching tube pair. When the switching tubes M1 and M4 are turned on and the switching tubes M2 and M3 are turned off, the voltage at the A terminal is greater than the voltage at the B terminal, and a forward current flows in the load and runs in a certain direction (for example, clockwise). When the switching tubes M2 and M3 are turned on and the switching tubes M1 and M4 are turned off, the voltage a...

AI Technical Summary

Problems solved by technology

However, this differential detection method often introduces significant common-mode noise components into the detection results, resulting in low Signal-to-nosie (SNR), which is not what we expect

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