Abstract: A digital receiver circuit is easily integrated into a single chip. A differential output amplifier circuit is used for performing a binarizing decision by a quantizer for a differential output. A peak detection circuit, an average value detection circuit, an operational amplifier and a transistor are provided for controlling an input impedance and an offset of the differential output amplifier circuit depending upon a differential output. Thus, a capacitor for alternating current coupling as required conventionally, becomes unnecessary to facilitate integration into a single chip with minimum number of parts by full DC coupling.