| 摘要 |
PROBLEM TO BE SOLVED: To provide a DC-DC converter whose light load efficiency is improved. SOLUTION: Potentials of both ends of a sensing resistor 25 are inputted to a comparator 31 via an offset power supply 32. If a potential of a non-reverse input terminal (+) is lower than a potential of a reverse input terminal (-) to which an offset voltage is added, it is detected that a load is light. If the light load is detected by the comparator 31, an oscillator 30 lowers a frequency of a clock signal CK and a control circuit 29 controls a MOS-FET 2 to be turned off until a reverse direction current is supplied to a choke coil 24.
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