Shayadri Valley College of Engineering & Technology , Rajuri

INTRODUCTION

Seminar:Operational AmplifierSub: Electronics Devices & Circuits

By:Pingat Amruta RajendraGunjal Swati BalkrushnaS.E.(E&TC)Guided By:Prof.Ashish Mulujkar

TITLEOperational Amplifier

INDEX

1.History2.Block Diagram3.Circuit 4.Advantage5.Disadvantage6.Future Scope7.Application8.conclude

History The term operational amplifier was first use by John

R. Rajazzini in 1947. Basically operational amplifier is multi stage amplifier which performs amplification ,addition, subs traction ,differentiation ,integration. In order to higher voltage gain we will have to use more than one amplifier together. All this will make the circuit very bulky. So instead of using such discrete amplifier people started using the amplifier in the integrated circuit IC form.

Circuit Symbol of Op-amp

IC Product

Ref:080114HKN Operational Amplifier 7

+

1

2

3

4

8

7

6

5

OFFSET NULL

-IN

+IN

V

N.C.

V+

OUTPUT

OFFSET NULL

Vout = −Vin (Rf / Ri)

Non-inverting amplifier

Inverting amplifier

Vout = Vin (1 + R2 / R1)

Ref:080114HKN Operational Amplifier 9

+

vi

Ra

vov-

v+

Rf

+

vi

Ra

vov-

v+

Rf

R2R1

+

vi vov-

v+

Rf

+

vi

vov-

v+

Rf

R2R1

Noninverting amplifier Noninverting input with voltage divider

ia

fo v

RR

R

R

Rv ))(1(

21

2

Voltage follower io vv

ia

fo v

R

Rv )1(

Less than unity gain

io vRR

Rv

21

2

Single-Ended Input

Ref:080114HKN Operational Amplifier 10

+

Vo

~Vi

+

Vo

~Vi

terminal : source – terminal : Ground

0o phase change

• + terminal : Ground• – terminal : Source• 180o phase change

Double-Ended Input

Ref:080114HKN Operational Amplifier 11

~V1

+

Vo

~V2

+

Vo~

Vd

• Differential input

•

• 0o phase shift change

between Vo and Vd

VVVd

Summing Amplifier

•V = − (Rf / R1) (V1 + V2 + ... + Vn) •For R1 = R2 = ... = Rn = Rf •V = − (V1 + V2 + ... + Vn)

Op-Amp Differentiator

Ref:080114HKN Operational Amplifier 13

RCdt

dVv io

+

RC

VoVi

0to t1 t2

0

to t1 t2

ADVANTAGESOperational amplifier having small size.Operational amplifier is linear & more

accurate analog integrated circuit.Cost of operational amplifier is less.Less power consumption compare to

other devices

Applicationaudio and video pre-amplifiers and buffers voltage comparators differential amplifiers differentiators and integrators filters precision rectifiers voltage and current regulators analogue calculators analogue-to-digital converters digital-to-analogue converters

Conclusion

Op-amp is best device in electrical circuit for

the amplification of week signal purpose.

THANK YOU

END