| 摘要 |
PROBLEM TO BE SOLVED: To provide a synchronous rectification switching DC-DC converter free from a restriction of ensuring the minimum on time of a main switch element under conditions of high input voltage and no load. SOLUTION: The DC-DC converter includes: a chopper circuit 1 having a main switch element 11, a rectification switch element 14, an inductor 12, and a smoothing capacitor 13; an error amplifier circuit 2; a control drive circuit 3 having a current detection circuit 36, a comparison circuit 32, an oscillation circuit 31, a NOR gate 35, a latch circuit 34, a drive circuit 33, and a dead time adjustment circuit 37; and a voltage detection circuit 4. The dead time of the rectification switch element 14 is lengthened with increase in output direct-current voltage V<SB>o</SB>by the dead time adjustment circuit 37. As a result, rise in output direct-current voltage V<SB>o</SB>is suppressed. COPYRIGHT: (C)2007,JPO&INPIT
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