An integrated circuit device includes a variable-gain amplifier, memory circuit and gain control update circuit. The variable-gain amplifier generates an amplified signal having an amplitude according to a gain control value that is stored, at least during a first interval, within the memory circuit. The update circuit generates an updated gain control value based on the amplified signal during the first interval, and outputs the updated gain control value to the memory circuit to be stored therein at a conclusion of the first interval.