Improving Bulk Driven CMOS OTA Performance Using Feedforward Technique

This paper presents an ultra-low-voltage ultra-low-power CMOS Operational Transconductance Amplifier (OTA), using a novel feed-forward technique. The proposed topology is based on a bulk driven input differential pair, and inclusion of a gain-stage in the Miller capacitor feedback path to enhance the pole-splitting effect. The main objective of the proposed OTA is to utilize idle current source devices in small signal paths to improve the OTA performance. Not only the DC gain of the proposed OTA is enhanced by 10dB, its unity gain bandwidth (UGB) is also increased by factor of 3 with no extra power dissipation. The proposed OTA is designed and simulated in 180nm CMOS technology consuming only 386nW under the supply voltage of 400mV.