The document discusses operational amplifiers (op-amps), including their history, components, characteristics, configurations, and applications. It describes how op-amps work as differential amplifiers, lists the pins of a common op-amp, and discusses ideal and real characteristics like input/output impedance and gain. It also explains various op-amp configurations like inverting, non-inverting, summing and integrating amplifiers. Finally, it provides examples of op-amp applications in electrocardiogram circuits and piezoelectric transducers.

2. › Introduction
› What is Op-Amp?
› Op-Amp pin Diagram
› Circuit Symbol and internal Circuit
› Characteristics of Op-Amp
› Parameter of Op-Amp
› Op-Amp’s Configuration
› Inverting Amplifier
› Non-inverting Amplifier
› Buffer
› Summing Amplifier
› Integrator
› Differentiator
› Application of Op-Amp
› References

3. The term “operational amplifier’’
denotes a special type of amplifier
that, by proper selection of its
external components, could be
configured for a variety of
operations.
First developed by Karl D.
Swartzel jr. in 1941 with vacuum
tube.
In 1963 Bob Widlar introduces
the op-amp that was to become
the industry standard.
Figure1: Vacuum tube Operational Amplifier

4.  An Operational Amplifier (Op-
Amp) is an integrated circuit that
uses external voltage to amplify the
input through a very high gain.
 Op amps are differential amplifiers,
and there output voltage is
proportional to the difference of
the two input voltages. Figure2: What an Op-Amp looks like in today’s world

5. There are 8 pins in a common Op-Amp, like 741 which is used many
instructional course.
•Pin1: Offset null
•Pin2: Inverting input terminal
•Pin3: Non-inverting input terminal
•Pin4: -VCC (negative voltage supply)
•Pin5: Offset null
•Pin6: Output terminal
•Pin7: +VCC(positive voltage supply)
•Pin8: No connection
Figure3: Pin Diagram of 741 Op-
Amp

6. Figure shows the symbol of Op-Amp. The power supply at vs+ & VS- to
make it works. The input terminal defined by the ‘-’ & “+”symbol are
designated inverting & non-inverting. The voltage w.r.t ground denoted as
V+ & V- and output voltage as Vout.
Figure4: Circuit Symbol of Op-Amp Figure5: Internal Circuit of Op-Amp

7. Infinite input impedance
Zero output impedance
Zero common-mode gain or,
infinite common mode rejection
ratio
Infinite open loop gain
Infinite bandwidth
Characteristics independent of
temperature
The input impedance between
150 kΩ to a few hundred mega ohm
The output impedance lies in the
range 0.75Ω to 100Ω
Voltage gain is typically 10 to 10
Characteristics change with
temperature very slightly
IDEAL REAL
3 6

8.  input offset voltage(Vio)
A small voltage required between the inputs of an
operational amplifier to make the output zero, is called input offset
voltage. • 2mv for 741 IC
 Input offset current(Iio)
The difference between the bias currents at the input
terminals of Op-Amps is called input offset current
• 200nA for 741 IC
Input bias current
Input bias current IB as the average value of the base current
entering into terminal of an op-amp
•700 nA for 741 IC
Input Resistance(Ri)
It is the equivalent resistance that can be measured at
either inverting or non-inverting inputs terminal with the other terminal
grounded • 2MΩ for 741 IC

9. Output Resistance(Ro)
It is the equivalent resistance that can be measured output
terminal and ground terminal
• 75Ω for 741IC
 Voltage gain(A)
Voltage gain is the ratio between output voltage and input
voltage • Open loop voltage gain for IC741 is 200,000
 Common Mode Rejection Ratio(CMMR)
It is define as the ratio of differential voltage gain Ad to
common voltage gain Acm
• 20 dB for 741 IC
Slew Rate(SR)
It is defined as the maximum rate of change of output voltage
• 0.5 V/us for 741 IC

10.  Inverting Amplifier
Non- inverting Amplifier
Summing Amplifier
Buffer Amplifier
Integrator
Differentiator

11. In Inverting Amplifier configuration the output voltage 180 degree out of
phase with respect to input voltage (i.e. if you apply positive voltage ,
output will be negative)
Figure6: Circuit diagram of inverting amplifier

12. In this configuration the output voltage and input voltage in same phase
( i.e. if you apply positive voltage, output will be positive)
Figure7: Circuit diagram of non-inverting amplifier

13. In this configuration the output voltage and input voltage are same in
amplitude and phase. (i.e. if you apply +1V , then output will be +1V)
Figure8: Circuit diagram of Buffer amplifier

14. If RF =R1=R2=R3=R , then the output voltage is exactly the inverted
algebraic sum of the input voltages
Figure9: Circuit diagram of summing amplifier

15. In this configuration the output voltage is the integral of input voltage
Figure10: Circuit diagram of integrator

16. In this configuration the output voltage is proportional to the time
derivative of the input voltage
Figure11: Circuit diagram of differentiator

17. o
Electrocardiogram(EKG)A
mplification
- Need to measure
difference in voltage from
lead1 and lead2
- 60Hz interference from
electrical equipment
oSimple EKG circuit
- Uses differential
amplifier to cancel common
mode signal and amplify
differential mode signal

18. o Realistic EKG circuit
- Uses two non-inverting
amplifiers to amplify voltage from
each lead, followed by differential
amplifier
- Forms and
amplifier
oPiezoelectric Transducer
- Used to measure force and
pressure
- Piezoelectric crystal generate
and electric charge in response to
deformation

19.  “Operational Amplifier”
https://en.wikipedia.org/wiki/Operational_amplifier
“Operational Amplifier Application”
https://en.wikipedia.org/wiki/Operational_amplifier_application
s
 Fundamental Principles of Electronics by “B Ghosh”
 Jung, Walter G. Op-Amp Applications Handbook .
Analog Devices , Inc. 2005.