Passive Compensation for Improved Settling and Large Signal Stabilization of Ring Amplifiers

Abstract

In this paper, passive compensation techniques are proposed: to improve the settling performance of a ring amplifier and to minimize the power consumption of ring amplifiers in high speed applications. The ring amplifier is an efficient solution for high accuracy amplification in sub-micron CMOS process. However, due to the multi stage structure of the ring amplifier, the need for stabilization increases the static power consumption of the amplifier in high speed and high accuracy applications. The proposed technique utilizes LHP zeros obtained from the switches in a switched capacitor feedback network to stabilize the large signal and small signal response of a ring amplifier. Transistor level simulations are used to validate the effect of passive compensation in a 65nm CMOS process. The ring amplifier is designed for an output settling accuracy of ≤0.02% and operated at 150MHz sampling rate. Using the proposed technique, transistor level simulation shows a 72% reduction in static power in comparison to the traditional compensation methods.