Design of Cascode-Compensated Opamps Based on Settling Time and Open-Loop Parameters

Considering the importance of settling behavior of operational amplifiers (op amps) for a given accuracy in many applications (like in switched-capacitor circuits), in this paper, a new methodology for the design of two-stage cascode-compensated op amps based on settling time is proposed. Concerning the application of the op amp, it specifies proper open-loop circuit parameters to obtain the desired settling time and closed-loop stability. As the effect of zeros in the open-loop transfer function has been taken into account, the proposed methodology becomes very accurate in achieving the required specifications. Simulation results are presented to show the effectiveness of the proposed methodology