operational transconductance amplifier (OpAmp) (OTA)

An OTA amplifier is a type of operational amplifier, except that the OTA amplifier has an extremely high impedance output and behaves like a current source.

An OTA amplifier converts the input voltage into an output current. This characteristic is equivalent to that of a transconductance. This is defined by the ratio of output current to input voltage.

OTA amplifiers are used in audio compression circuits and audio limiter circuits because they have a higher rate of change and thus significantly improve compressor dynamics compared to voltage controlled amplifiers( VCA).