Rail-to-rail low-power fully differential OTA utilizing adaptive biasing and partial feedback

Abstract

A fully differential rail-to-rail Operational Transconductance Amplifier (OTA) with improved DC-gain and reduced power consumption is proposed in this paper. By using the adaptive biasing circuit and two differential inputs, a low stand-by current can be obtained together with reduced power consumption. The DC-gain of the proposed OTA is improved by adding a partial feedback loop. A Common-Mode Feedback (CMFB) circuit is required for fully differential rail-to-rail operation. Simulations show that the OTA topology has a low stand-by power consumption of 96µW and a high FoM of 3.84 [(V/µs.pF)/µW] for a load capacitor of 10pF.