Patent ID: 6275541
Filing Date: 2001-08-14
Classification: H04B,H04L

Abstract:
A digital receiver circuit including a photoelectric converter element for converting an input light into an electric signal, a differential output amplifier circuit receiving an output of said photoelectric converter element, a control circuit controlling an offset and an input impedance of said differential output amplifier circuit, and a quantizer for binarizing an output of said differential output amplifier, said control circuit further comprising:first and second peak detection circuits respectively detecting peak values of said differential output;a peak difference detection circuit for detecting a difference between two peak values detected by said first and second peak detection circuits;an offset control circuit for controlling the offset of said differential output amplification circuit depending upon a result of detection of said peak difference detection circuit;an average value detection circuit for deriving an average value of said two peak values detected by said first and second peak detection circuits;a comparator circuit for comparing derived average value with a predetermined reference voltage; andan input impedance control circuit for controlling an input impedance of said differential output amplification circuits depending upon a result of the comparison of said comparing circuit.