In this paper, an ultra-low-power ultra-low-voltage CMOS operational transconductance amplifier (OTA) with a full rail-to-rail input/output swing is presented. The proposed two-stage OTA is based on the body-driven current mirror (CM) amplifier topology with Gm-C frequency compensation technique. In addition, a transconductance boosting technique is used to enhance the performance of the input stage structure without adversely affecting the noise performance. Simulation results in a 0.18 μm CMOS technology show that the proposed OTA achieves an 86 dB DC gain and a gain-bandwidth of 21.9 kHz while driving a 15 pF load. The amplifier consumes 292 nW @ 0.5 V which makes it suitable for ultra-low-power applications.
