Optimum Sizing and Compensation of Two-Stage CMOS Amplifiers Based On a Time-Domain Approach

This paper presents a new design methodology for optimum sizing and compensation of two-stage amplifiers based on a time-domain approach. This methodology allows the analysis of different topologies of amplifiers with an unlimited number of poles and zeros. The optimization process is performed by a software tool based on a genetic algorithm kernel integrated with open-source BSIM3v3 code. Using this tool together with the proposed design flow it is demonstrated, with consistent simulated results, that the optimum step-response is achieved using hybrid cascode-compensation comprising two un-equal sized capacitors.