UNIVERSAL COLLEGE OF ENGG. AND TECH.

ANALOG ELECTRONICS

AIM: OP-AMP AMPLIFICATION, DC AND AC AMPLIFIERS, SCALING AND SUMMING AMPLIFIERS

Prepared By: Group:- 12 (C) Devansh Dave 130460109011 Parita Bhavsar 130460109007

Guided By: Prof. Kapil Dave

FLOW OF PRESENTATION

• • • • • • • • Op-Amp TERMINOLOGY 741 Op-Amp Schematic Diagram of Op-Amp Inverting Amplifiers Non-Inverting Amplifiers Summing Amplifiers Scaling Amplifiers

OP-AMP

• Op-Amp-An active circuit element designed to perform mathematical operations of addition, subtraction, multiplication, division, differentiation and integration.

• High performance linear amplifier requires a power source to operate.

that

TERMINOLOGY

• •

Gain-

Amount of amplification produced by an Op-Amp. Gain is independent from the supply voltage (power given for the Op-Amp to operate).

Open-Loop Mode-

Function of an Op-Amp when the feedback resistor (R f ) is zero. The Op-Amp operates as a comparator and not as a linear amplifier.

TERMINOLOGY

•

Comparator-

Compares the –V and +V inputs to see which is greater and returns a result.

•

Bandwidth-

The range of frequency at which an Op-Amp will function. (Ideal = ∞)

TERMINOLOGY

• • •

Slew Rate (V/µs)-

Amount of time it takes for the Op-Amp to step to another voltage level.

(Non-Ideal)

Input Offset Voltage-

Even when there is no input voltage the Op-Amp gives off a small voltage. This can be canceled out by use of the Offset Null pin on the chip. (Non-Ideal)

Common Mode Rejection Ratio (CMRR)-

Ability of an Op-Amp to reject a signal applied to both inputs simultaneously.

741 OP-AMP

Maximum Ratings Characteristics

Supply Voltage ±18 V Power Dissipation 500 mW Diff. Input Voltage ±30 V Input Voltage ±15 V Operating Temperature 0°C to 70°C Input Offset Voltage Input Resistance CMMR Bandwidth Slew Rate Offset Null 1 - INPUT 2 + INPUT 3 - V 4 + 8 7 No Connection + V 6 Output 5 Offset Null 2 to 6 mV .3 to 2 MΩ 70 to 90 dB .5 to 1.5 MHz .5 V/µs

Schematic Diagram of 741 OP-AMP

OP-AMP TYPES

Op-amp DC AC

DC OP-AMPS

• In DC op-amps, the output signal changes in response to changes in its DC input levels.

• A DC amplifier can be inverting, non-inverting or differential.

• Let us see them in detail

INVERTING OP-AMP

• Here the inverting circuit diagram of Op-Amp is shown,

INVERTING OP-AMP

• The input is given to the Inverting terminal of Op-Amp so we get an Inverted output with 180° phase difference and out of phase.

NON-INVERTING

OP-AMP

NON INVERTING AMPLIFIER

• The input signal is given to non-inverting terminal of Op-Amp. The output is without any phase difference and in phase to input.

DIFFERENTIAL AMPLIFIER

If R 1 = R 2 and R f = R g :

DIFFERENTIAL AMPLIFIER

• It amplifies the difference between two voltages but does not amplify the particular voltages.

• Where V in + and A d and V in are the input voltages is the differential gain

SUMMING AMPLIFIER

SUMMING AMPLIFIER

K CL

@"

A

"

i a i b i c i f v R v out a a



v R b b



v R c c

 

v out R f

   

R R a f v a



R f R b v b



R f R c v c

 

K CL

@"

A

"

i a i b i c i f v a R a v out



v R b b



v R c c

   

R f R a v a

 

v out R f



R f R b v b



R f R c v c

 

SCALING AMPLIFIER

REFERENCES

• • • Ramakant A Gayakwad, Op-Amps and Linear integrated circuits, Prentice Hall of India • K.R.Botkar, Integrated Circuits, Khanna Publishers www.google.com

www.wikipedia.org

THANK YOU