| 摘要 |
A power supply device, and an LED(Light Emitting Diode) device and an electronic device using the same are provided to prevent a variation of a load current by alternating an operation mode between a first operation mode and an alpha operation mode or between the alpha operation mode and a beta operation mode when applying a power voltage. A power supply device(1) includes a charge pump circuit(2), a load current driving circuit(4), a reference current source(5), a comparison circuit(7), and a control circuit(8). The charge pump circuit supplies a driving voltage for driving an LED(3) as a load. The load current driving circuit passes a load current through the LED. The reference current source includes a current mirror circuit(6) which passes a current with the same value as a reference current to a reference path(9) through a current mirror. The comparison circuit compares an output voltage(Vdin) of the LED with a reference voltage(Vref). The control circuit controls a step-up rate of the charge pump circuit based on the comparison result of the comparison circuit.
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