| 摘要 |
An embodiment of the present invention provides a power supply circuit including a charge-pumping booster section which uses switching elements provided only by N-channel transistors yet does not have a problem of voltage drop by threshold value. When a boosted voltage is obtained at a first terminal of a first capacitor in a booster section, a booster control section supplies this boosted voltage to a third capacitor, to boost the voltage further thereby turning ON a first transistor. When a boosted voltage is obtained at a first terminal of a second capacitor in the booster section, the booster control section supplies this boosted voltage to a fourth capacitor, to boost the voltage further thereby turning ON a second transistor. This arrangement eliminates a problem of voltage drop by threshold value in the first and the second transistors which serve as output-side switching elements.
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