A current sensing circuit with bootstrap effect for DC-DC converters

In this paper, a novel current sensing circuit is proposed to satisfy high voltage requirement in inductor current measurement for DC/DC converters. The proposed current sensing circuit is based on Matching Complimentary Filter (MCF) technique. Besides, the novel technique uses a bootstrap circuit to cut off the approach between the sensing circuit and ground, making the supply voltage of sensing circuit floating with its input signal. The proposed scheme is verified on 35V input with 53V output DC/DC boost converter and the experimental results are presented to demonstrate the theoretical analysis. The experimental results illustrate that the proposed circuit could be applied on high voltage systems.