Operational amplifier (OP – AMP) Linear built-in circuits are being used in a quantity of digital applications, similar to in the fields like communication, scientific electronics, instrumentation manipulate and so on. An foremost linear IC is an operational amplifier. OP-AMP is an effective state gadget equipped of sensing and amplifying dc and ac input indicators. OP-AMP is an amplifier with two inputs (differential inputs) and a single output. OP-AMP consists of 20 transistors, 11 resistors and one capacitor. It probably requires a confident and bad vigour provide (twin vigor deliver). This makes it possible for the output voltage to swing positive and terrible with recognize to floor The primary traits of OP-AMP are : (i) very excessive input impedance and even infinity which produces negligible present on the inputs, (ii) very excessive acquire, (iii) very low output impedance and even zero, so as to not have an impact on the output of the amplifier via loading. An OP-AMP is so named, due to the fact it was once at first designed to perform mathematical operations akin to addition, subtraction, multiplication, division, integration, differentiation and so on in analog pc. Nowdays OP-AMPs are utilized in analog pc operations and in timing circuits.