Pseudo-differential CMOS analog front-end circuit for wide-bandwidth optical probe current sensor

摘要

In this paper, we present a pseudo-differential analog front-end (AFE) circuit for a novel optical probe current sensor (OPCS) aimed for high-frequency power electronics. It employs a regulated cascode transimpedance amplifier (RGC-TIA) to achieve a high gain and a large bandwidth without using an extremely high performance operational amplifier. The AFE circuit is designed in a 0.18 mu m standard CMOS technology achieving a high transimpedance gain of 120 dB Omega and high cut off frequency of 16 MHz. The measured slew rate is 70 V/mu s and the input referred current noise is 1.02 pA/root Hz. The magnetic resolution and bandwidth of OPCS are estimated to be 1.29mT(rms) and 16 MHz, respectively; the bandwidth is higher than that of the reported Hall effect current sensor. (C) 2018 The Japan Society of Applied Physics.