Split compensation two-stage operational amplifier based on inverter input structure

The invention belongs to the technical field of electronics and relates to the frequency compensation technology of operational amplifiers in analog integrated circuits. The split compensation two-stage operational amplifier comprises a two-stage operational amplifier. A first-stage operational amplifier is composed of N-channel metal oxide semiconductor (NMOS) tubes (M1N, M2N, M3 and M4) and P-channel metal oxide semiconductor (PMOS) tubes (M1P, M2P and M0). A second-stage operational amplifier is composed of a PMOS tube M5P and an NMOS tube M5N. A traditional Miller capacitor is divided into a Cm1 portion and a Cm2 portion to finish frequency compensation of the operational amplifier. A first frequency compensation capacitor Cm1 is connected with the position between the output end of the first operational amplifier and the output end of the whole two-stage operational amplifier. A second frequency compensation capacitor Cm2 is connected with the position between a connection point of a source of the NMOS tube M2N and a drain of the NMOS tube M4 in the first-stage operational amplifier and the output end of the whole two-stage operational amplifier. The split compensation two-stage operational amplifier has strong robustness and higher unit grain bandwidth and output slew rate due to the fact that non-dominant poles and stray parameter are not related.