# Semiconductors/Op-Amps

## Contents

## Op-Amps Intro[edit]

Op-Amps stands for Operational Amplifier, a device usually manufactured as an Integrated Circuit (IC) . User don't need to know about the Itegrated Circuit inside in order to work with Op-Amps . All you need to know is that Op-Amps acts as an amplifier, it amplifies the difference of the 2 different voltages at input by a gain or amplification factor A

Output of an operational amplifier:

Ideally is assumed to be equal to infinity. However, in practical op-amps, it has a high value. Furthermore, the gain is a function of frequency.

Below is the most commonly used configuration of Op-Amps

## Negative Amplifier[edit]

- The output voltage is a negative voltage equal to the input voltage amplified by a factor

## Positive Amplifier[edit]

- The output voltage is a positive voltage equal to the input voltage amplified by a factor

## Positive Buffer[edit]

- From the circuit of Positive Amplifier, If R
_{2}= 0 thì V_{o}= V_{i}

## Negative Buffer[edit]

- From the circuit of Negative Amplifier, If R
_{f}/R_{i}= 1 then V_{o}= - V_{i}