The Operational Amplifier is more versatile and important building blocks in analog circuit design. Operational amplifiers (OpAmps) are integral part of many analog and mixed signal systems. Op amps with vastly different levels of complexity used to realize functions high speed amplifier ranging from dc bias generation to or filtering. The design of an opAmp continues to pose a challenge as the supply voltage and transistor channel lengths scale down with each generation of CMOS technologies. A wide variety of electronic applications deal with small signal inputs. Operational amplifiers are amplifiers that have sufficiently high forward gain.For most of the analog systems and mixed signal ICs, OpAmps are used for the comparator and switched capacitor based sample and hold circuits. The motivation for the design of OpAmp includes a wide area of application ranging from home appliances to biomedical, communication and signal processing purposes.Designers always make a tradeoff between performance parameters while designing an OpAmp.