| 摘要 |
PROBLEM TO BE SOLVED: To prevent MOS transistors from being broken by a rush current from an input terminal side when starting boosting operation from a boosting stopped state. SOLUTION: A current leak to the input terminal (Vin) side from an output terminal (Vout) side caused by a parasitic diode of the second MOS transistor (M2) is suppressed by turning off the third MOS transistor (M3) and turning on the fourth MOS transistor (M4) at the boosting operation. A current leak to the output terminal side from the input terminal side caused by the parasitic diode of the second MOS transistor is suppressed by turning on the third MOS transistor and turning off the fourth MOS transistor in the boosting stopped state. When staring the boosting operation from the boosting stopped state, an electrode at the output terminal side of the second MOS transistor is charged prior to the switching of the board bias state of the second MOS transistor, and the rush current is prevented from flowing toward an output terminal from the input terminal side via the parasitic diode of the second MOS transistor. COPYRIGHT: (C)2008,JPO&INPIT
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