A current inputted from a first input terminal and a reference current generated by an internal reference current generator circuit, which are in phase, are inputted to a reference current selector circuit by which either the inputted current or the reference current is selected. The selected current is temporarily phase-inverted by a current inverter circuit and drives a current mirror circuit of a current distributor circuit (or a reference current regulator circuit) for duplicating the reference current and distributing them. Currents, each of which is in phase with the reference current or the inputted current and has same current value as that of the reference current or the inputted current, can be generated in the output side transistors of the current mirror circuit. In order to realize this, a second output side transistor is provided in the current mirror circuit so that a current, which is in phase with the reference current and has substantially equal value to that of the selected current, is supplied from the output terminal to a next stage integrated circuit as an input reference current.