Editing Analog multiplier (section)

===Voltage-controlled amplifier===
If one input of an analog multiplier is held at a steady voltage, a signal at the second input is scaled in proportion to the level on the fixed input. This may be considered a voltage-controlled amplifier or [[variable-gain amplifier]]. Applications are for electronic volume control and [[automatic gain control]] (AGC). Although analog multipliers are often used for such applications, voltage-controlled amplifiers are not necessarily true analog multipliers.{{cn|date=April 2025}} For example, an [[integrated circuit]] designed to be used as a volume control may have a signal input designed for 1&nbsp;Vp-p, and a control input designed for 0-5&nbsp;V dc; that is, the two inputs are not symmetrical and the control input has a limited bandwidth.

By contrast, in what is generally considered to be a ''true'' analog multiplier, the two signal inputs have identical characteristics. Applications specific to a true analog multiplier are those where both inputs are signals, for example in a [[frequency mixer]] or an analog circuit to implement a [[discrete Fourier transform]]. Because the precision required for the device to be accurate and linear over the input range, a true analog multiplier is generally a much more expensive part than a voltage-controlled amplifier.