Linear Integrated Circuits are being used in a number of applications such as in audio and radio communication, medical electronics, instrumentation and control etc. An important linear IC is the Operational Amplifier (OPAMP) introduced in 1940s.Robert J Widlar at Fairchild brought out the popular OPAMP IC 741 between 1964 and 1968. It uses BJTs and FETs fabricated along with other components on a single chip of silicon. The OPAMP is a multi terminal device that has complex internal circuitry. The manufacturers have done a wonderful job that OPAMP's performance can be described by its terminal characteristics and those external components that are connected to it. ICs have now become an integral part of all electronic circuits and work at even low voltages. Its cost is also low due to bulk production.Due to the low cost, small size, versatility, flexibility and dependability of OPAMPs they are used in the fields of process control, communication, computers and measuring devices.