Analysis of Stability in Multistage Feedforward Operational Transconductance Amplifiers using Successive One-Pole Approximation

This paper presents analysis results of the operational transconductance amplifiers (OTAs) that combine feedforward paths and multistage amplifiers to achieve high-gain wideband operation as well as frequency compensation. To analyze multistage feedforward OTAs and provide an intuitive design method, the successive one-pole approximation (SOPA) is used for each substage of a multistage feedforward OTA. Using SOPA, the stability analysis is carried out from the two-stage feedforward OTA to the four-stage feedforward OTA in this work.