| 摘要 |
<p>PURPOSE: A device for driving an LED and a control method thereof are provided to stably drive an LED by minimizing a ripple current which increases a junction temperature of the LED. CONSTITUTION: A device for driving an LED includes a converter power source(95), a measurement current source(101), a central control part(105), a floating switch, and a falling time compensating circuit. The converter power source receives a DC power, and outputs a driving power which drives an LED(21). The measurement current source applies a measurement current in order to send a forward voltage to the LED. The central control part calculates a temperature value corresponding to a size of the forward voltage. The central control part compares the temperature value with a predetermined temperature value, and outputs a PWM signal. The floating switch applies the measurement current from the measurement current source to the LED. The floating switch switches the measurement current source and the converter power source in order to apply the driving power from the converter power source to the LED. The falling time compensating circuit discharges parasitic capacitance formed inside the LED when switching from the converter power source to the measurement current source.</p> |
