DESIGN AND ANALYSIS OF A TWO STAGE MILLER COMPENSATED OP-AMP SUITABLE FOR ADC APPLICATIONS

D.S. Shylu, D. Jackuline Moni, Benazir Kooran

Abstract: In this paper a two stage RC Miller compensated op-amp and its analysis is presented. In order to obtain a high dc gain, a two stage op-amp is used. The two stage op-amp consists of a telescopic op-amp in the first stage and a common source output rail-to-rail stage in the second stage .In addition to the dc gain ,the main advantage of this op-amp is the voltage swing .The simulated results shows a DC gain of 60dB ,phase margin of 500 ,CMRR of 48.7dB and a slew rate of 100V/µs respectively .The total power dissipation obtained from the op-amp circuit is 1.3mW. For comparison, a similar op-amp which uses a double cascode telescopic input has been realized .And both these op-amps are designed using 0.18µm CMOS process.

Keywords: Cascoded telescopic op-amp, CMOS technology, CMRR, Miller compensated op-amp, pipelined analog-todigital converter, Slew Rate, telescopic op-amp.

DOI: https://doi.org/10.15623/ijret.2014.0319045