A 1.8 V 11.02 μW single-ended inverter-based OTA with 113.62 dB gain

This paper presents a low power 1.8 V single-ended operational transconductance amplifier (OTA) with a very high dc gain targeted for audio applications. Cascoding and gain boosting are employed to achieve the high gain. The amplifier is implemented in UMC 180 nm CMOS technology. For a typical process corner, the amplifier provides a dc gain of 113.62 dB and a unity gain bandwidth of 2.49 MHz at 62.9° phase margin with capacitive load of 2.5 pF. The amplifier consumes only 6.12 μA of quiescent current from 1.8 V supply. The amplifier exhibits good performance across all the process corners with the use of body bias technique.