| 摘要 |
PROBLEM TO BE SOLVED: To provide a DC/DC converter capable of preventing a malfunction, when power is turned on. SOLUTION: The DC/DC converter 10A comprises an oscillator 12 for allowing an oscillation signal to oscillate; a reference voltage generation circuit 13 for generating a reference voltage Vref; a soft start circuit 14 connected to the reference voltage generation circuit for outputting voltage that rises gradually, from 0 V to the reference voltage Vref, when power is turned on; an output voltage detection means for detecting the power output voltage Vout to output a feedback voltage V<SB>FB</SB>; an error amplifier 15A for obtaining the difference between the output voltage of the soft start circuit 14 and the feedback voltage V<SB>FB</SB>to output an error signal; a pulse width demodulation comparator 16 for comparing the error signal with the oscillation one, to supply a pulse width demodulation signal to a switching element 11; and an initial circuit 18 for forcedly setting the output voltage of the error amplifier 15A to zero potential and substantially for only a prescribed period, when the power is turned on. COPYRIGHT: (C)2007,JPO&INPIT
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