To obtain a second supply voltage by an active potentiometer having no external elements like a capacitor without almost a delay as an internal supply voltage in an integrated circuit(IC) which has a first circuit in which a supply voltage is equal to an external supply voltage of the IC and a second circuit in which the supply voltage is smaller than the external supply voltage thereof.

A potentiometer is structured by first resistance potentiometers (R1, R2) between a supply voltage terminal (Pad) and a reference voltage, an impedance converter (T1) which is successively connected to the first resistance potentiometers, and a circuit for controlling a partial voltage of a tap (X) of the first resistance potentiometers (R1, R2) in correspondence to a load.