Improved Design Procedure for Two-Stage CMOS Op Amp Employing Current Buffer

In this paper an improved version of the design procedure of two-stage CMOS operational amplifier employing a Miller capacitor and a current buffer is presented. Unlike the op amp obtained from the previously reported design procedure, in which the unity gain frequency is approximated by the gain bandwidth product, the resulting op amp from the proposed procedure has frequency response characteristics much closer to the desired values. Design example of the proposed procedure is given and the results compared to the previous method.