| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply circuit of smaller size and lower power consumption, capable of stably supplying an electric power to a load circuit by efficiently using a micro power obtained from a power generating element. SOLUTION: A voltage VIN from a solar cell 1 is boosted by a pump-up circuit 20 of a boosting circuit part 2. The boosted voltage VA is stabilized by a regulator circuit 50 of a power supply circuit part 5. The stabilized output voltage VOUT charges a secondary battery 3 and supplies a power to a load circuit 4. A control circuit part 6 makes the secondary battery 3 supply power to an oscillation circuit 51 that oscillates and outputs a clock signal which is a base of the gate signal of a switch element of the pump-up circuit 50 if the voltage VIN of the solar cell 1 is low even under illumination, whereas a boosted voltage V01 is supplied as a power source if the boosted voltage V01 of the pump-up circuit 20 exceeds a specified value. COPYRIGHT: (C)2007,JPO&INPIT
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