Patent ID: 7560915
Filing Date: 2009-07-14
Classification: H02M

Abstract:
1. A power supply apparatus comprising: a linear regulator which receives an input voltage and outputs a regulated voltage; a charge pump type booster circuit which boosts the regulated voltage at a preset gain and outputs a boosted output voltage; a voltage comparator which compares the boosted output voltage with a predetermined threshold voltage and outputs a boost suspension signal when the boosted output voltage is higher than the threshold voltage; a first auxiliary circuit which forcibly lowers the regulated voltage input to the booster circuit in response to the boost suspension signal, a second auxiliary circuit which forcibly lowers the boosted output voltage of the charge pump type booster circuit in response to the boost suspension signal; a current limiter circuit which limits the supply of current from the linear regulator to the charge pump type booster circuit in response to the boost suspension signal; and means which suspends a boosting operation of the charge pump type booster circuit in response to the boost suspension signal, wherein the linear regulator receives the boosted output voltages from the charge pump type booster circuit and generates the regulated voltage by feedback so that the boosted output voltage is equal to a preset voltage and wherein the first auxiliary circuit, the second auxiliary circuit, the current limiter circuit and the means which suspends the boosting operation are controlled based on the boost suspension signal from the voltage comparator.