Low voltage CMOS op-amp with rail-to-rail input/output swing

As the supply voltage to a standard CMOS op-amp is reduced, the input common mode range and the output swing get reduced drastically. Special biasing circuits have to be used to raise them up to rail-to-rail supply voltage. Three low voltage op-amps with new biasing circuits have been proposed in this paper and their performance evaluated. The op-amp design is focused on dynamic range and high drive capability.