Low-power high-bandwidth preamplifier with improved common mode feedback stability

Abstract

A low-power high feedback factor common mode feedback technique using subthreshold MOSFETs is presented in this paper. The proposed approach is an improved version of the conventional resistive degeneration of current mirrors. The proposed technique is implemented in preamplifier which is designed in UMC 180 nm technology with 1.8V power supply and 225nA bias current. The SPICE simulations show that the proposed method achieves 1.9 times increase in the differential mode bandwidth besides 2.5 times increase in the common mode feedback factor compared to the conventional approach for the same power consumption.