Abstract
In this paper, an ultralow-power ultralow-voltage CMOS operational transconductance amplifier (OTA) with a rail-to-rail input/output swing is presented. The proposed two-stage OTA is designed based on a body-driven current mirror (CM) amplifier with a 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 for 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 ultralow-power applications.