# Electronics Fundamentals/Integrated circuit/Operational Amplifier

## Operational Amplifier or Op Amp

An Operational amplifier is an Integrated circuit, which has a number of electronic components inside a single "chip" or package. Many of these devices are packaged in eight-pin packages, but there are also some devices which are provided in smaller or larger packages. There are also versions which contain multiple op amps in a single package. A typical example of the former is the extremely common 741, for which the specifications are shown below. An example of the latter type is the 324, which contains four op amp circuits in a single 14-pin package.

## Symbol

Pin Number Function
IC 741
1 Null Offset
2 Inverted Voltage
3 Non-Inverted Voltage
4 Negative Voltage Source
5 Not Used
6 Output
7 Positive Voltage Source
8 Not Used

op-amp
• V+: (non-inverting input)
• V: (inverting input)
• Vout: (output
• VS+: (positive power supply)
• VS−: (negative power supply)

## Operation

Operational Amplifier is used to amplify the difference of two input voltages.

${\displaystyle V_{o}=A(V_{+}-V_{-})}$

Op Amp can also be used as Inverting or Non Invering Voltage Amplifier

${\displaystyle V_{o}=AV_{+}withV_{-}=0}$
${\displaystyle V_{o}=AV_{-}withV_{+}=0}$

Or as a Voltage Comparator of the two input voltages

If ${\displaystyle V_{+}>V_{-}}$  Then ${\displaystyle V_{o}=V_{s}s}$
If ${\displaystyle V_{+}  Then ${\displaystyle V_{o}=-V_{s}s}$
If ${\displaystyle V_{+}=V_{-}}$  Then ${\displaystyle V_{o}=0}$