Switching Power Supply and its Control Circuit, and Electronic Apparatus Employing Such Switching Power Supply

摘要

A control circuit for controlling a switching element in a switching power supply by generating a switching signal is disclosed. The control circuit may include a short start circuit that generates a switching signal so that an output voltage of the switching power supply gradually increases for a period until the output voltage reaches a predetermined reference voltage. The soft start circuit may increase the output voltage at a first limiting speed when the output voltage is lower than a predetermined threshold voltage, and may increase the output voltage at a second limiting speed which is set higher than the first limiting speed when the output voltage is higher than the threshold voltage.