Design and implementation of general purpose opamp using multipath frequency compensation

Abstract

This paper shows the multipath frequency compensation in a general purpose operational amplifier. Firstly, it deals with the requirements of a general purpose opamp and introduces the need of the frequency compensation in the current circuits. Then, the rules to integrate multipath in an opamp are developed and the transfer function is presented and compared to the one of the nested miller compensation. Next, an implementation of the multipath nested miller compensation is described. Finally, simulation result which proves the efficiency of this compensation is given. The multipath compensation improves the classical compensation structure as it does not cutoff the initial unity gain frequency by four but only by two.