A low voltage CMOS class AB operational transconductance amplifier

This paper presents a new low voltage class-AB operational transconductance amplifier (OTA). A low impedance buffering circuit is employed to provide an accurate voltage level shift for low-noise class-AB operation and to enable operation from a supply voltage down to 1.5 V. The proposed OTA can achieve a fast settling time which is not slew-rate limited at a low quiescent current when driving large capacitive loads.