| 摘要 |
PURPOSE: A switch mode LED driver circuit and a driving method thereof are provided to increase the driving efficiency of the circuit by performing the measurement and control of the LED current apart from the shape of the circuit through the mode which indirectly measures the voltage from both ends of the inductor. CONSTITUTION: A voltage sensing part (110) senses the inductor voltage which is hanged in both ends of the inductor (20). A searching part (120) searches the section in which the current value of the inductor became 0 by using the inductor voltage which is sensed in the voltage sensing part. The electric current calculation department (130) calculates the current value of the inductor by using the inductor voltage value from the arbitrary point of time to the other arbitrary point of time which is in the section which is searched. An acquisition unit (140) obtains the current value of the LED (30) from the current value of the calculated inductor. The control unit (150) controls the on/off driving of the switch element (10) by comparing the current value of the inductor which is calculated and the predetermined reference current value. [Reference numerals] (110) Voltage sensing part; (120) Searching part; (130) Electric current calculation department; (140) Acquisition unit; (150) Control unit |
