Abstract: A new way to calculate the operating point of the circuit is proposed and an encapsulated device evaluator based on BSIM3v3MOS model is integrated,to improve the accuracy of equation-based synthesis approach.At the same time,a new strategy is presented to synthesize operational amplifier quickly,to meet all the specifications and is immune to all variation,including operating/manufacturing variation.It has been demonstrated that this approach can synthesize manufacturable deep-submicron CMOS operational amplifier in very short run time.