| 摘要 |
PROBLEM TO BE SOLVED: To improve the efficiency of a charge pump LED driver. SOLUTION: The charge pump LED driver (10) is provided with a charge pump (12) raising an input voltage (V<SB>IN</SB>) at a pressure rise rate and outputting an output voltage (V<SB>OUT</SB>), and a selector selecting the pressure rise rate of the charge pump. The driver applies output voltages to first to sixth light emitting diodes (LED1 to LED6), and drives the light emitting diodes. The selector (16) monitors not only the input voltage (V<SB>IN</SB>) but also a forward drop voltage (V<SB>F</SB>) and switches the pressure rise rate. COPYRIGHT: (C)2006,JPO&NCIPI
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