A digitally programmable folded cascode OTA with variable load applications

Abstract

Folded Cascode OTA is widely used in analog and mixed signal domain. It gains special importance in switched capacitor circuits where folded cascode architecture is the default choice for op-amps. In this work, a digitally programmable single ended folded cascode operational transconductance amplifier (OTA) is presented. Observations show that the OTA can be made digitally programmable over a wide range of unity gain frequency with compromise on phase margin. It is also shown that adding additional load branches in parallel allows wide tuning of the DC gain and phase margin. The programmable OTA is thus designed and the pre and post layout simulation results are presented.