Attenuator circuit

摘要

An attenuator circuit for electrically controlling an amount of attenuation of an input signal, the attenuator circuit includes a main attenuator circuit unit including: a memory device for storing a plurality of amounts of attenuation as parameters; a control circuit for reading one of the parameters from the memory device, to output a control signal according to the parameter being read; a potentiometer having a plurality of control terminals, the potentiometer for providing a control voltage which is varied in steps according to the control signal applied to the control terminals, and an automatic gain control (AGC) amplifier for attenuating an input signal by controlling a gain in response to the control voltage provided by the potentiometer to attenuate an input signal so as to vary the amount of attenuation in steps.