An op-amp (operational amplifier) is an electronic device that amplifies the difference between two input voltages. It is commonly used in electronic circuits for signal processing, filtering, and amplification.
An op-amp consists of a differential amplifier stage, followed by a high-gain amplifier stage. The input voltages are compared and the resulting difference is amplified to a higher output voltage. The output voltage is limited by the power supply voltage and the op-amp's gain.
The ideal op-amp has infinite gain, infinite input impedance, and zero output impedance. This means that it amplifies the input signal perfectly without drawing any current from the input source and producing an output voltage that is not affected by the load resistance.
Op-amps are used in a wide range of electronic circuits, such as audio amplifiers, filters, oscillators, and voltage regulators. They are also used in instrumentation and control systems, as well as in signal processing and communication systems.
When selecting an op-amp, factors to consider include the required gain and bandwidth, input and output impedance, supply voltage range, and output voltage swing. It is also important to consider the op-amp's noise characteristics, temperature range, and cost.