Current-Sensing Topology with Multi Resistors in Parallel and Its Protection Circuit

Current-sensing topology with multi resistors in series has limitations improving the dynamic range of current acquisition, so a sensing parallel is proposed. The overcurrent state shunt circuit cannot be latched, resulting protection hiccups. A dual threshold-detection designed to achieve latching and self-recovery. rectified mean applied for magnitude detection its validity proved. But delay ripple output waveform may also cause Combining Fourier representation, transform inverse transform, time domain expressions three common waveforms are obtained. Furthermore, estimation formulas residual amplitude derived. In an experiment, hiccup issue was eliminated, while constants hysteresis ratios circuits were properly set according theoretical calculation results. With five resistors, ratio maximum minimum single channel reaches 1.28×104, which higher than counterparts multiple resistors. advantages confirmed.