Low Power Cascaded Three Stage Amplifier with Multipath Nested Miller Compensation

This paper proposes a design for a low power cascaded three stage Operational Amplifier, with frequency compensation by Nested Miller Compensation which could be made to operate at low voltage supplies. The multipath technique is used to increase the bandwidth by converting the system into a two stage amplifier at high frequencies. The Op-Amp is designed in 180 nm technology and operates at a 3 V power supply with a gain of 115 dB, bandwidth of 103 Mhz, phase margin of 45 degrees and a settling time of 80-90 ns. Graph and simulation results are provided to verify the performance and to demonstrate the advantages of this three stage cascaded topology.