A Compact Single-Transistor Current Source for Analog Design in Nanometer Digital CMOS

High-performance single-transistor current source is crucial to analog design in advanced CMOS processes. Various approaches to enhance the output resistance of single-transistor current source are studied in this brief in the view of adaptive control. Then a novel compact implementation is proposed, and used to build a fully differential OTA with improved dc gain and common-mode rejection in a 55 nm CMOS with a supply of 1.1 V.