Design and Modeling of a CMOS Fully Differential Transconductance Operational Amplifier

Research of high-speed and high-gain transconductance amplifier with the structure of gain-boost,the mathematical modeling and Matlab simulation is presented for gain-boost operational amplifier.Designed operational amplifier is used in 12 bit 100 M SPSADC,and the optimal design on the auxiliary amplifier bandwidth can be obtained.Simulation results show that gain is 106 dB which increses of 55 dB if an auxiliary operational amplifier is added.Besides,if we the auxiliary operational,dominant pole is greatly reduced and non-dominant pole slightly decreases,but the addition of auxiliary amplifier does not affect the speed of the operational amplifier.