What is operational amplifier? Write its characteristics.

Q.) What is operational amplifier? Write its characteristics.

 Subject: Electronic Devices and Circuits

Operational Amplifier (Op-Amp)

An operational amplifier, often referred to as an op-amp, is a direct-coupled high-gain electronic voltage amplifier that has a differential input and, usually, a single-ended output. It is a versatile device mostly used for performing mathematical operations such as addition, subtraction, integration, and differentiation.

Characteristics of an Op-Amp:

  1. High Gain: Op-amps offer very high open-loop voltage gain, typically ranging from 100,000 to several million. This means that even a small voltage difference between the input terminals results in a significant voltage amplification at the output.

  2. Differential Input: Op-amps have two input terminals, the non-inverting (+) and the inverting (-). The voltage difference between these two terminals (Vid) is amplified and appears at the output.

  3. Single-Ended Output: Op-amps typically have a single output terminal that provides the amplified voltage. The output voltage (Vo) is proportional to the voltage difference between the input terminals.

  4. Virtual Short Circuit: The input terminals of an ideal op-amp are considered to be virtually shorted, i.e., the voltage difference between the inverting and non-inverting inputs is practically zero. This characteristic is fundamental in understanding the behavior of op-amps in various circuits.

  5. High Input Impedance: Op-amps have very high input impedance, typically in the range of megaohms or higher. This means that they draw minimal current from the input source, making them suitable for use with high-impedance signal sources.

  6. Low Output Impedance: The output impedance of an op-amp is typically very low, often in the range of a few ohms or less. This means that the op-amp can drive loads with low impedance without significant voltage drop or distortion.

  7. Negative Feedback: Op-amps are often used in negative feedback configurations, where a portion of the output signal is fed back to one of the input terminals. This feedback reduces the overall gain and improves the linearity, stability, and bandwidth of the amplifier.

The combination of these characteristics makes op-amps versatile building blocks in various electronic circuits, including amplifiers, buffers, comparators, integrators, and filters.