| 摘要 |
PROBLEM TO BE SOLVED: To provide a DC-DC converter that suppresses output fluctuations due to switching operation of switching elements while suppressing a reverse current due to a relationship with a load current, and also to provide its reverse-current suppression method. SOLUTION: Driving switching elements for synchronous rectification is set as an operation such that pulse signals (PWM_A, PWM_B) for switching operation and a load-current detection value (CURR_OUTPUT) are inputted and a duty ratio is increased/decreased according to the load-current detection value CURR_OUTPUT. An ON-duty is increased in accordance with an increase in load current regarding drive signals (synchronous rectification A, synchronous rectification B) for synchronous rectification so as to make adjustment that finally achieves the maximum ON-duty. The optimal ON/OFF switching is made according to a load current. COPYRIGHT: (C)2009,JPO&INPIT
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