| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply circuit capable of detecting the output current, without the use of shunt resistor, corresponding to application of overcurrent protective functional capability, even under size reduction. SOLUTION: In the power supply circuit that uses a DC/DC converter IC circuit 2 of switching mode controlling the output voltage via alteration of switching pulse frequency, a current detection circuit 11, connected to the output B of the DC/DC converter IC circuit 2 via a condenser 10, is arranged so as to implement detection of the output current for overcurrent protection, based on the frequency of alternating current component contained in the output voltage of the DC/DC converter IC circuit 2. COPYRIGHT: (C)2009,JPO&INPIT
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