PROBLEM TO BE SOLVED: To permit driving by low voltage by making a 1st voltage compression circuit constructed with P channel MOSFET and making a 2nd voltage compression circuit constructed with an N channel MOSFET. SOLUTION: A P channel voltage compression circuit 101 steps down input voltage Vin (a) and reference voltage Vref 1 in a prescribed ratio and outputs them. An N channel voltage compression circuit 102 steps down input voltage Vin (b) and the reference voltage Vref 1 in a prescribed ratio. It is possible to apply voltage that is higher than the voltage Vref 1 to the gate voltage of PMOSs 40 to 43 of a current conversion circuit 106 and to apply voltage that is lower than the voltage Vref 1 to the gate voltage of PMOSs 20 to 23 of 1st and 2nd voltage conversion circuits 103 and 104. Thus, it is possible to operate the PMOSs 20 to 23 in a pentode area even if power supply voltage Vcc is low.