| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply apparatus using a combination of a series type power supply and a charge pump type booster circuit, capable of ensuring the gentle slope of the drooping characteristic in an overcurrent limiting operation, thereby stably supplying even a load current in excess of a current limit value, and suppressing oscillation during current limiting operation. SOLUTION: A series regulator (12, 30, 21, 22) for outputting a regulated voltage Vcp and a charge pump type booster circuit 20 for outputting an output voltage Vout by boosting the regulated voltage Vcp are connected in series. The series regulator is controlled so that the output voltage Vout is maintained constant. A main circuit current 11 of the series regulator is subject to current limitation by a current detecting circuit 40. An excess signal commensurate with a current detection value in excess of a current limitation reference value is generated by an excess current generating circuit 50. In accordance with the excess signal, a voltage control signal is lowered in level. COPYRIGHT: (C)2006,JPO&NCIPI
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