A DTMOS-based 1 V opamp

Abstract

In this paper, we present a new opamp based on dynamic threshold voltage (DTMOS) transistors for low voltage applications (1 V). The opamp is a two stage configuration, with differential input pairs followed by a single ended class AB output. The input stage uses DTMOS devices for input common-mode range enhancement. The performed simulation shows a dc open loop gain of 64.4 dB, a phase margin of 64/spl deg/ and unity gain frequency of 35.7 MHz under a 10 k/spl Omega/ and 5 pF load, using the 0.18 /spl mu/m CMOS technology. The opamp has a CMRR of 84 dB, input and output swings of 0.7 V and 0.9 V respectively.