| 摘要 |
PROBLEM TO BE SOLVED: To start a DC-DC converter rapidly in a pre-biased state. SOLUTION: This switching control circuit, including an N-channel MOSFET, a rectification element, an inductor 22, a first capacitor, and a second capacitor to one end of which a first voltage for turning on the N-channel MOSFET 30 is supplied and the other end of which is connected to the output electrode of the N-channel MOSFET 30, controls the ON/OFF of the N-channel MOSFET of the DC-DC converter which generates an output voltage of a target level in one end of the first capacitor. This control circuit comprises a voltage monitoring circuit, which outputs a monitoring signal showing whether a voltage across the second capacitor is higher than a predetermined level; a charging circuit, which supplies a second voltage higher than the first voltage to one end of the second capacitor when the voltage across the second capacitor is lower than the predetermined level; and a drive circuit, which drives the N-channel MOSFET according to an input signal using the voltage of the one end of the second capacitor as a drive power source. COPYRIGHT: (C)2008,JPO&INPIT
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