Error Amplifier in LDO

This project considers two distinct error amplifier configurations (simple differential pair and cascode configuration) in the context of LDOs. Both of them were theoretically analyzed with proper explanations and the expectations were stated as well. In order to verify the theory, the circuits were simulated to obtain their frequency response, transfer function, and to study the effect of common mode bias on the output voltage. Thus, by contrasting between simple differential amplifier and its cascoded version, one can deduce that there are clear tradeoffs when choosing among them. While the former has greater 3-dB frequency and more voltage legroom, it is inferior to the cascoded version of differential amplifer in terms of other parameters. The latter as seen from the simulations provided superior DM gain while lowering the CM-DM gain. Hence it is reasonable to suggest that the choice should be given to the one which best fits the application.