To realize a single phase signal/differential signal conversion means that can solve a problem of a signal loss or mismatching of phases and amplitudes between differential outputs that can no longer be disregarded in a conventional method where a differential configuration is adopted for signals in an analog circuit section to implement a measure against a leaked noise in an analog/digital hybrid LSI.

A constant voltage is applied to a gate of one transistor(TR) of a differential amplifier to the source of which a constant current source is connected, the drain of a TR of an opposite conductivity type is respectively connected to the drain of each TR of the differential amplifier via a load inductor respectively, and a single-phase input signal is simultaneously applied to a source of the TR of the opposite conductivity type connected to the TR whose gate receives the constant voltage and to the other TR of the differential amplifier.