Variable gain control circuit and integrated circuit device having the same

摘要

A variable gain control circuit is provided comprising a bipolar transistor for amplifying an input signal applied to a base, and outputs an output signal via a collector; a serial exchanging unit connected between an emitter of the bipolar transistor; a first voltage node; a parallel exchanging unit connected between the collector of the bipolar transistor and the first voltage node, and wherein the gain of the variable gain control circuit increases in a high gain mode by activating the serial exchanging unit and deactivating the parallel exchanging unit, and the gain of the variable gain control circuit decreases in a low gain mode by deactivating the serial exchanging unit and activating the parallel exchanging unit.