A 1.2 V rail-to-rail low-power opamp with replica amplifier gain enhancement

Abstract

This paper presents an architecture for a CMOS high-swing 1.2 V low-power fully differential class-AB amplifier (opamp) with a DC-gain of 52 dB. A low-voltage differential input stage is applied as the basic architecture. The replica gain enhancement technique is used to increase the DC-gain without degrading the output swing. Furthermore, this gain enhancement concept does not increase the minimal supply voltage and also allows scaling of the replica amplifier. The power dissipation is 200 /spl mu/W, providing a gainbandwidth (GBW) of 1.9 MHz with a capacitive load of 30 pF.