Patent ID: 10135444

Abstract:
The booster precharges a boost-voltage-output terminal to a predetermined voltage before voltage-boosting start by a charge-pump circuit in the booster. While alternately switching one capacitive electrode of a pumping capacitance between first and second voltages, the charge-pump circuit periodically applies a third voltage to the other capacitive electrode, in which the voltage is boosted by lifting up the third voltage each switching. The resultant boost voltage is successively supplied to a stabilization capacitance through a MOS switch circuit for output. Thus, a boost voltage boosted to a sum voltage of the second and third voltages can be obtained. Using a precharge voltage produced by the precharge circuit in the booster as the third voltage can make a MOS switch circuit operable to supply the third voltage and the MOS switch circuit for boost voltage output smaller than a voltage under the sum voltage of the second and third voltages.