Rail-to-rail two stage CMOS operational amplifier: A comparative analysis

This paper presents different low voltage CMOS operational amplifiers. Threshold reduction techniques are foreseen with the utilization of Bulk driven approach to reduce the supply voltage. Disadvantages identified with bulk driven approach are talked about and strategies to enhance them are proposed. To increase transconductance of the Op-Amp, cascode input stage and cross coupled output stage are utilized with no expansion in area as well as bulk driven MOSFETS can be utilized alongside partial positive feedback. These methods help in increment of dc gain. Supply voltage scaling has been the central factor because of which gain increments, efficient power utilization is there and on-chip are reduce.