| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply device which detects a light load state accurately. SOLUTION: The power supply device includes a first switch and a second switch connected in series between an input voltage and a reference voltage, an inductor provided between the connection of the switches and an output terminal from which an output voltage is output, and a control unit which controls switching of the first and second switches alternately at a predetermined switching period according to an error of the output voltage to a target one. The control unit changes the switching period from a first period to a second one longer than the first period according to a voltage of the connection point at the time when the second switch is in a conducting state. COPYRIGHT: (C)2010,JPO&INPIT |
