| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of unused charge-pump capacity (capacitor) when the boosting system of a charge-pump circuit is switched. SOLUTION: In a charge-pump circuit unit 11, a connection switching terminal SW1 selects a power source voltage VDD, a logic inversion buffer gate G2 and a capacitor C2 increase the power source voltage VDD by twice (2×VDD), and a connection switching terminal SW3 outputs a boosted voltage to an external unit, as a boosted control voltage VB. In a charge-pump circuit unit 12, a connection switching terminal SW1' selects a boosting control voltage VB (2×VDD) outputted from the charge-pump circuit unit 11, and a logic inversion buffer gate G2' and a capacitor C2' increase the VDD by three times. The boosted voltage (3×VDD) is outputted directed toward an internal power supply line 21 via an NMOS transistor M4' and an internal voltage VPP is generated. COPYRIGHT: (C)2008,JPO&INPIT
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