| 20090237050 | Switching power supply - A switching power supply, which operates intermittently under a light load for suppressing electric power consumption, reduces output voltage variations caused when a load current increases rapidly from a light load state, and reduces output voltage ringing. The switching power supply includes a comparator that compares a feedback signal obtained by isolating the output from an error amplifier with a burst threshold value and a comparator that compares the feedback signal with a power-supply-interruption threshold value preset to be lower than the burst threshold value. The switching power supply stops output of a driving pulse from a driver circuit when the feedback signal is lower than the burst threshold value. The switching power supply also stops the output of operation power from first power supply circuit when the feedback signal is lower than the power-supply-interruption threshold value. | 09-24-2009 |
