An rail-to-rail operational amplifier is presented in this paper, which is designed by with two op amp, the first level of the structure is the complementary differential structure which will providing input for the operational amplifier, the second level is designed with the structure of folding cascode to get a high gain. The operational amplifier is designed with the TSMC 0.35u m3.3VCMOS mixed analog-digital technology library. The simulated results show that the operational amplifier has a DC gain of 110dB,a GBW of 9.5MHz,a static power dissipation of 0.95mW,a phase margin of 73°,a voltage slew rate of 8.2V/μS,an input and output range of 0-3.3V,when operating at 3.3V power supply and a 20pF output load.
Design and Analysis of a High-Gain Rail-To-Rail Operational Amplifier