Patent ID: 8619444

Claim:
A voltage booster system, comprising: a regulator for outputting a constant voltage, said regulator including a differential amplifier unit for inputting a reference voltage and a feedback voltage according to the voltage of the output terminal, said regulator further including an output stage portion including an PN connection element having one end portion connected to an application terminal of a power source voltage and another end portion connected to the output terminal, said PN connection element being configured to be controlled according to an output signal of the differential amplifier unit; and a charge pump circuit for boosting a voltage of an output terminal of the regulator, said charge pump circuit including a first capacitor to which the voltage of the output terminal is applied to be charged, a second capacitor, a third capacitor, a first switching section, and a second switching section, wherein said charge pump circuit is configured to perform a first step and a second step as a voltage boosting operation, in which, in the first step, the first switching section becomes an on state and the second switching section becomes an off state so that the voltage of the output terminal is applied to the second capacitor to accumulate electric charges in the second capacitor, and in the second step, the first switching section becomes the off state and the second switching section becomes the on state so that a combined voltage of a first voltage between both end portions of the first capacitor and a second voltage between both end portions of the second capacitor is applied to the third capacitor through the second switching section to accumulate electric charges in the second capacitor, said PN connection element is configured to increase an internal resistivity thereof after the regulator starts up until a first specific period of time is elapsed relative to the internal resistivity after the first specific period of time is elapsed so that an electric current flowing from the application terminal of the power source voltage to the first capacitor is restricted, and said first switching section is configured to increase an on resistivity thereof after the voltage boosting operation is started until a second specific period of time is elapsed relative to that after the second specific period of time is elapsed.