operational amplifier

operational amplifier amplifier whose output voltage is proportional to the negative of its input voltage and that boosts the amplitude of an input signal many times, i.e., has a very high gain. It is usually connected so that part of the output is fed back to the input. Operational amplifiers were originally developed to be used in synthesizing mathematical operations in analog computers , hence their name. Because of recent advances in semiconductor technology, they have become available as integrated circuits. They are widely used when a closely controlled amount of gain or some form of signal processing is necessary in an electronic system.

operational amplifier (op-amp) A very high gain voltage amplifier having a differential input, i.e. its output voltage is proportional to (and very much greater than) the voltage difference between its two inputs. Operational amplifiers usually have feedback circuits of resistors and/or capacitors connected between their output and inputs. These circuits make op-amps operate as voltage amplifiers with a gain precisely defined by the values of the resistors, or else enable them to perform mathematical operations, such as integration, or signal-conditioning functions, such as filtering. Operational amplifiers are generally employed in linear circuits, but with the addition of nonlinear components (e.g. diodes) other functions such as precision rectification and logarithmic amplification can be effected.