A 0.5 v fully differential transimpedance amplifier in 65-nm CMOS technology

Abstract

This paper proposes a novel fully differential ultra-low voltage transimpedance amplifier (TIA) based on a CMOS translinear circuit. Following a simple bias strategy, its transimpedance gain can be adjusted to the desired accuracy either by means of an external resistor or using internal voltage and current references. To a first order approach, the transresistance results independent from technological parameters. The amplifier does not need a common mode feedback circuit (CMFB) to set the quiescent output voltages. The circuit was sized and simulated in a 65-nm CMOS process to comply with a 10kΩ transimpedance gain and 1MHz@1pF bandwidth. For a 0.5V supply voltage the total power consumption is 78.5μW.