PSRR分析

caroline11

Abstract —Intemafly compensated CMOS op amps have ~en widely used in sampled-analog signaf processing applications over the past several years; however, the popular two-stage op amp suffers from poor ac power supply rejection to one of the power rails. This paper presents two circuits that overcome the PSRR problems of the earlier amplifiec one for virtual ground applications such as switched-capacitor integrators, and the other for buffer applications requiring wide common-mode input range. Small signal an@ysis is developed for the open loop and PSRR responses of the two amplifiers. In addition, design guidelines are suggested and test results are presented。