In this paper we present an ultra-low voltage gate-input operational transconductance amplifier using pMOS input devices and nMOS load devices with local common-mode feedback. This topology has a good intrinsic common-mode rejection. Simulations for a two-stage, 0.5 V fully differential operational transconductance amplifier (OTA) with a gain of 55 dB and a common-mode rejection ratio of 61 dB are reported. The amplifier consumes 77 /spl mu/W and has a gain-bandwidth product of 8.7 MHz when designed in 0.18 /spl mu/m CMOS technology.