Design and analysis of a high speed operational amplifier made by 60 nm gate-length MOSFETs

In this paper, a high speed operational amplifier (op amp) with 60 nm gate length MOSFET (nano-MOSFET) is presented. Cascode input stage is implemented to improve frequency response. After verifying the availability of cascode form in designing high speed op amp via SPICE model, we give simulation results to prove the speed of cascode op amp has no advantage compared with simple two-stage op amp in this ultra-short channel occasion. Our simulation also suggest it is important to choose transistor parameter, as small output resistance can severely deteriorate circuit performance.