| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power supply device which reduces an occupying area on a semiconductor substrate and make an external part unnecessary in the power supply device having a soft start function. Ž<P>SOLUTION: This power supply device includes a charge pump circuit 1, a soft start circuit 2, and a soft start signal generation circuit 3. The charge pump circuit 1 converts an input voltage into a set voltage. The soft start circuit 2 performs the soft start operation of the charge pump circuit 1 based on a soft start signal S1. The soft start signal generation circuit 3 accumulates an electric charge in a first capacitor, transfers the accumulated electric charge of the first capacitor to a second capacitor for cumulative accumulation, compares an integrated value of the electric charge accumulated in the second capacitor with a predetermined value, and generates the soft start signal S1 according to the comparison result. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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