| 摘要 |
PROBLEM TO BE SOLVED: To reduce the number of parts and make the switching power supply small, while surely preventing oscillations due to interference between converters connected in multi-stage. SOLUTION: The switching power supply 1 includes a negative OR circuit 5. Control signals VP1 and VP2 for driving switching elements 10 and 11 are entered as an input in the negative OR circuit 5, to generate a synchronized signal SYNC, in synchronization to a dead time of the control signals VP1 and VP2. A PWM drive unit 4 generates a drive control signal OUT having a certain duty ratio in synchronization with the synchronized signal SYNC to drive a switching element 6 under control. As a result, the switching element 6 is operated with an operating frequency that is two times as large as those of the switching elements 10 and 11, while the switching element 6 is synchronized with the switching elements 10 and 11. COPYRIGHT: (C)2003,JPO
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