| 摘要 |
PROBLEM TO BE SOLVED: To prevent deterioration or breakdown in LEDs due to large currents flowing to the LEDs when changing the boosting rates of boosting circuits in LED drives that include the charge pump boosting circuit and light light-emitting diodes. SOLUTION: The LED drive includes: the boosting circuit (11) boosting an input voltage for output and changing the boosting rate in steps, a constant current drive circuit (15) for generating a predetermined drive current in the light-emitting diode by a voltage boosted by the boosting circuit for output, and a voltage comparison circuit (CMP) for comparing an output voltage of the boosting circuit with a predetermined detection voltage. In this case, the constant current drive circuit reduces a current flowing to the light-emitting diode or suppresses an increase in the current, according to an output of the voltage comparison circuit when the output voltage is rapidly increased by changing the boosting rate of the boosting circuit. COPYRIGHT: (C)2011,JPO&INPIT
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