Operational amplifier PREPARED BY V.Thamizharasan,AP/ECE Erode Sengunthar Engineering College

Basic information of op-amp Op-amp is a direct coupled high gain amplifier Used to amplify dc and ac input signals To perform mathematical operation It can be used as active filters, amplifiers, oscillators, comparators, regulators and etc. Symbol of op-amp: Non inverting input terminal Output terminal Inverting input terminal

Packages Metal can (TO) package The dual in line package(DIP) Flat package or flat pack

Dual in line welded seal ceramic package Cont., ceramic flat package To-5 style package with straight leads. dual in line plastic package Dual in line welded seal ceramic package

Power supply connection

Manufacturers for linear ICs

741 versions

Equivalent circuit of op-amp

Ideal/Practical characteristics of op-amp

Features of op-amp 741 No external frequency compensation(internally frequency compensated) Short circuit protection Offset-null capability Large common mode and differential mode voltage range three different packages Available various operating temperature ranges Low power consumption No latch up problem

General operational amplifier stages 1 & 2 stages provide high gain and high input resistance 3buffer and level shifter provide high input impedance and adjust d.c voltage. 4provide low output impedance

Basic differential amplifier Suppress any undesired noise signal CMRRbetter for high 4 different configuration 1.Differential input and differential output (or) Dual innput and balanced output 2.Differential input and signle ended output 3.Sigle input ,differential output 4.Single input single ended output. Mode of operation: 1.Common mode operation 2.Differential mode operation

Cont.,

Cont.,

Differential input signal applied

Improvement of CMRR

Internal circuit diagram of UA 741 op-amp

Motorola MC1530 op-amp