This book presents various techniques and methodology to improve the performance of the Operational Amplifier. Operational Amplifier plays very important role in analog and mixed circuits. The designing of op-amps puts new challenges in low power applications with reduced channel length devices. All electronics gadgets are getting advanced and technology moving from analog domain to digital domain but backbone of all digital circuit is analog. Op-Amp is very useful in Bio-Medical Field. Here a new technique Split Length Transistor technique is also introduced with Operational Transconductance Amplifier