This document discusses operational amplifiers (op-amps). It defines an op-amp as a high-gain direct coupled amplifier consisting of one or more differential amplifiers. It provides a block diagram and symbol for an op-amp. It then explains how an op-amp works by amplifying the difference between its input terminals. Next, it lists several ideal specifications and features of an op-amp including infinite gain, bandwidth, input impedance and more. The document discusses advantages like easy gain adjustment with negative feedback. It provides examples of applications such as filters, oscillators and converters. Finally, it provides references for more information.

1. Patil Suraj Shrikant
Msc-I (Electronic)
Poona College,Pune

2. Operational –
amplifier

3. What is op-amp?
• Op-amp is high gain direct coupled amplifire
usually consisting of one or more differential
amplifire.
• In present day op-amp is basic building block
of electronic system.

4. Block diagram

5. Symbol

6. Pin diagram

8. WORKING
The amplifier's differential inputs consist of a V+ input and a V− input,
and ideally the op-amp amplifies only the difference in voltage between the two,
which is called the differential input voltage. The output voltage of the op-amp is
given by the equation:
where V+ is the voltage at the non-inverting terminal, V− is the voltage at the
inverting terminal and AOL is the open-loop gain of the amplifier (the term "open-
loop" refers to the absence of a feedback loop from the output to the input).
The magnitude of AOL is typically very large—100,000 or more for integrated
circuit op- amps—and therefore even a quite small difference between V+ and
V− drives the amplifier output nearly to the supply voltage. Situations in which
the output voltage is equal or greater than the supply voltage are referred to as
saturation of the amplifier.

9. Specification & Feature
Infinite open-loop gain (when doing theoretical analysis, a limit may be taken as open
loop gain AOL goes to infinity).
Infinite bandwidth (i.e., the frequency magnitude response is considered to be flat
everywhere with zero phase shift).
Infinite input impedance (so, in the diagram, , and zero current flows from to . )
Zero input current (i.e., there is assumed to be no leakage or bias current into the
device).
Zero input offset voltage (i.e., when the input terminals are shorted so that , the
output is a virtual ground .

10. Infinite slew rate (i.e., the rate of change of the output voltage is unbounded) and
power bandwidth (full output voltage and current available at all frequencies).
Zero output impedance (i.e. so that output voltage does not vary with output
current).
Zero noise.
Infinite Common-mode rejection ratio (CMRR).
Infinite Power supply rejection ratio for both power supply rails.

11. Advantages
The use of negative feedback makes it easy to
adjust the voltage gain. The voltage gain obtained is
predictable

12. Dis-Advantages
The disadvantages are the loss of voltage gain and the need
for a high impedance differential amplifier circuit. With the Op-
Amp these disadvantages are no longer valid, and most
amplifier systems are designed using op-amps with a negative
feedback loop to control the gain.

13. Applications
Use in electronics system design
Positive feedback
Negative feedback
audio- and video-frequency pre-amplifiers and buffers
differential amplifiers
differentiators and integrators filters
precision rectifiers
precision peak detectors
voltage and current regulators
analog calculators
analog-to-digital converters
digital-to-analog converters
voltage clamps
oscillators and waveform generators

14. Reference
Linear integrated circuit
WWW.Wikipedia.com
WWW.Google.com

15. THANKS
…
premrajpatil2327@gmail.com