Charge pump circuit allowing efficient electric charge transfer

摘要

In a charge pump unit circuit, a P channel MOS transistor is connected between a gate and a drain of switching N channel MOS transistor. The P channel MOS transistor is controlled to be on/off by a switching circuit. A voltage doubling circuit generates a clock signal having amplitude twice that of power supply voltage. The clock signal is applied to a capacitor to increase the potential of the gate of the N channel MOS transistor. Thus, resistance of the N channel MOS transistor sufficiently is reduced and transfer efficiency of positive charge is enhanced.