A rail-to-rail CMOS amplifier with improved current efficiency for MEMS geophone applications

Abstract In this study, a two-stage rail-to-rail amplifier with improved current efficiency is presented for microelectric mechanical system (MEMS) geophone applications, when operating in the saturated region. With the proposed recycling current method in the input stage, the amplifier gains improved unity-gain bandwidth (GBW) and DC gain with little power consumption. Based on the SMIC 180 nm process, the simulation results demonstrate that the proposed amplifier achieves rail-to-rail input/output, 92 dB DC gain and 4.8 MHz GBW with 1.2 V supply voltage.