Hybrid cascode compensation for two-stage CMOS operational amplifiers

This paper presents the analysis of a hybrid cascode compensation scheme which is used in two-stage CMOS operational transconductance amplifiers (OTAs). The open loop signal transfer function is derived to allow the accurate estimation of the poles and zeros. This analytical approach shows that the nondominant poles and zeros of the hybrid cascode compensation are about 40 percent greater than the conventional cascode compensation. Circuit level simulation results are provided to show the accuracy of the calculated expressions and also the usefulness of the proposed cascode compensation technique.