Performance Improvement of Folded Cascode and Recyclic Folded Cascode Operational Amplifier

This paper presents compensation technique using Single Miller Compensation Nulling Resistor (SMCNR) for improving gain & PSRR of Folded Cascode operational amplifier (FC op-amp) and Recyclic Folded Cascode operational amplifier (RFC op-amp). The conventional FC op-amp provides gain of 55.44dB and PSRR of 36.51dB. When one MOSFET compensation technique is used 129.19 dB (133.03% improvement) gain and 73.71 dB (101.85% improvement) PSRR is obtained for FC op-amp. Moreover, 2 MOSFET compensation technique provides gain of 110.96 dB (100.15% improvement) and PSRR of 55.52 dB (52.03% improvement). Furthermore, conventional RFC op-amp provides gain of 77.18dB and PSRR of 29.54dB. RFC op-amp with 1 MOSFET compensation provides gain of 135.81 dB (75.96% improvement) and PSRR is 60.01 dB (103.17% improvement). Moreover, 2 MOSFET compensation technique provides gain and PSRR of 123.65 dB (60.21% improvement) and 46.46 dB (57.27% improvement) respectively. All simulation results are obtained in cadence virtuoso using SCL 180nm CMOS technology.