| 摘要 |
PROBLEM TO BE SOLVED: To prevent a current from pouring into a parasitic diode, in a charge pump operated under different kinds of power supplies. SOLUTION: In the charge pump 1 includes an operation mode for charging a flying capacitor by an input power supply HPVDD via a P-channel transistor P1, at charging operation and a high-power mode for charging the flying capacitor by an input power supply SPVDD (>HPVDD) via a P-channel transistor P5, in the operation mode, the P-channel transistor P1 is turned ON/OFF, with the P-channel transistor P5 and a potential of an N-well being provided with the P-channel transistor P1 being OFF and the HPVDD, respectively. In the high-power mode, the P-channel transistor P5 is turned ON/OFF, with the P channel transistor P1 and the N-well being provided with the P-channel transistor P1 which is turned OFF and in a floating state, respectively. COPYRIGHT: (C)2011,JPO&INPIT |
