| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a DC-DC converter which supplies stable direct-current power without element breakage even when an input voltage rises rapidly and even when a high input voltage lasts for a long time. Ž<P>SOLUTION: The DC-DC converter is a synchronous rectification type DC-DC converter which has a main switch element Q1 and a rectifying switch element Q2. In the DC-DC converter, the rectifying switch element Q2 is constituted of a rectifying transistor element Tr2 and a rectifying diode element Di2, determines an input voltage Vi or a rise rate dVi/dt of the input voltage, releases a complementary ON-OFF operation of the main switch element Q1 and the rectifying transistor element Tr2 when the determined value exceeds a prescribed reference value, and sets a state that both the main switch element Q1 and the rectifying transistor element Tr2 are kept OFF together for longer time than dead time TD. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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