An NMOS transistor-based high-gain operational amplifier designed in 0.25-micron CMOS technology

Abstract

This project describes in detail the process of designing and simulating at first a one stage folded cascode operational amplifier using 0.25 um CMOS Technology with the self-biasing scheme for the NMOS differential input stage is discussed here. The design of the required circuits is done using the LTspice simulator. We will see that the simulation results approximately matches with the desired and theoretically calculated performance values. We are changing width values to bring all the transistors of the circuit in saturation. Then two Stage Folded Cascode Operational Amplifier with Miller compensation technique for the NMOS input. The operational amplifiers circuit is designed with 0.25 µm CMOS Technology using LTspice software. The applied methodology to implement the circuit design for a given specification has clearly described including all the design equation has been presented. All the parameter like DC Gain and Phase Margin (PM) are presented and discussed. Finally, we have got after performance analysis that designed circuit based on NMOS input provide a 96 DC Gain.