摘要 |
A reverse current is prevented in a charge pump circuit. A complementary pair of clocks CLK and *CLK varies while a first through a fourth charge transfer MOS transistors M 11, M 12, M 13 and M 14 are turned off. Then the second charge transfer MOS transistor M 12 is turned on to discharge a first pumping capacitor CA and the third charge transfer MOS transistor M 13 is turned on to charge a second pumping capacitor CB. Next, the complementary pair of clocks CLK and *CLK varies after the first through the fourth charge transfer MOS transistors M 11, M 12, M 13 and M 14 are turned off again. Then the fourth charge transfer MOS transistor M 14 is turned on to discharge the second pumping capacitor CB and the first charge transfer MOS transistor M 11 is turned on to charge the first pumping capacitor CA.
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