A Unity-Gain Buffer with Reduced Offset and Gain Error

A unity-gain buffer has been fabricated in 0.35-mum CMOS technology. The circuit uses feed forward and local feedback in a cascaded source follower circuit as well as two global feedback loops: one to reduce the output resistance, gain error, and offset and a second loop to further reduce gain error. The buffer consumes 3.7 mW at 3.3 V and has a bandwidth of 92 MHz when driving a 13-pF capacitive load