Design of a High Gain CMOS Operational Amplifier with Gain Boosting Technique

This paper presents the design of a fully differential CMOS amplifier with a high gain and a large unity gain frequency.The operational amplifier will be used in a high speed high resolution pipelined analog to digital converter.The main amplifier is a folded cascode amplifier.Auxiliary feedback amplifiers and switched capacitor common mode feedback circuit are employed.The simulation results show that the open loop DC gain of the opamp is 106dB,and the unity gain frequency is 167 MHz while driving a load of 2 pF,and the amplifier is suitable for using in a high speed,high resolution analog to digital converter.