Operational Amplifiers

What are Op Amps?

An operational Amplifier or op-amp for short, is fundamentally a voltage amplifying device designed to be used with external feedback components such as resistors and capacitors between its output and input terminals. These feedback components determine the resulting function or “operation” of the amplifier and by virtue of the different feedback configurations whether resistive, capacitive or both, the amplifier can perform a variety of different operations, giving rise to its name of “Operational Amplifier.”  

Input and Output Terminals of an Operational Amplifier

An op-amp has two input terminals and one output terminal. The op-amp also has two voltage supply terminals as seen above. Two input terminals form the differential input. We call the terminal, marked with negative (-) sign as the inverting terminal and the terminal marked with positive (+) sign as the non-inverting terminal of the operational amplifier. If we apply an input signal at the inverting terminal (-) then the amplified output signal is 180o out of phase concerning the applied input signal. If we apply an input signal to the non-inverting terminal (+) then the output signal obtained will be in phase, i.e. it will have no phase shift concerning the input signal.

Applications of Op Amps

Operational amplifiers are particularly versatile circuit blocks. They find applications in a host of different circuits where their attributes of high gain, high input impedance, low output impedance and a differential input enable them to provide a high-performance circuit with a minimum of components.

By using negative, and sometimes positive feedback around the op amp chip they can be used in many applications and circuits to provide a variety of different functions from amplifiers and filters to oscillators, integrators and many other functions.

There are many op amps circuits that cover most of the main analogue functions that are needed. As a result of this, operational amplifiers have become the workhorse of the analogue electronics designer.

More Applications and Advantages of Op Amps

Op Amps can also be used as

1. Amplifiers
2. Active filters
3. Arithmetic circuits.
4. Log/antilog amp
5. Voltage comparators
6. Waveform Generators
7. Precision rectifiers
8. Multipliers
9. Timers

Some advantages of using Op Amps are  

• It has a smaller size.
• Its reliability is higher than conventional amplifier
• Reduced cost as compared to its discrete circuit parts.
• Less power consumption
• Easy to replace