GREEN UNIVERSITY OF BANGLADESH

Department: EEE (Eve)

Prepared By:

Foyaz AhmedID# 143010007

Course Title: Electronics IIPrepared For:

Nusrat AlimLecturer, GUB

Basic of OP-AMP

OPERATIONAL AMPLIFIER

An operational amplifier or OP AMP is a very high gain differential amplifier with high input impedance and low output impedance.

A basic OP AMP has 2 input and 1 output

-

+ VO , OUTPUT

2

3

6

+ VCC

4

7

- VCC

INPUT

1

5

OP-AMP LM741 IC Pin Assignment NULL OFFSET 1

INVERTING INPUT

NONINVERTING INPUT

- Vcc NULL OFFSET 2

Output

+Vcc

COMP1

2

3

4

8

7

6

5

LM 741 OP AMP IC PIN ASSIGNMENT

Single ended Input operation results when the input signal is connected to one input and with the other input is connected to the ground.

SINGLE ENDED INPUT 

-

+

VO

2

3

6

+ VCC

4

7

- VCC

Grounded

SINGLE ENDED INPUT 

12 VVVd A double-ended input can be designed using a single input or using double inputs

DOUBLE ENDED INPUT 

DOUBLE ENDED INPUT WITH

SINGLE INPUT

-

+

VO

2

3

6

+ VCC

4

7

- VCC

Vd

Single input

DOUBLE ENDED INPUT WITH

DOUBLE INPUT

-

+

VO

2

3

6

+ VCC

4

7

- VCC

V2

V1

TWO INPUTS

COMMON INPUT

When both input signals are the same, a common signal element due to the two inputs can be defined as the average of the sum of the two signals.

2121 VVVC

OUTPUT VOLTAGE

The resulting output voltage of any op-amp can be defined as,

ccddO VAVAV

Where, Ad = Differential gain of the amplifier Ac = Common-mode gain of the amplifier