Patent ID: 8030857

Claim:
A backlight LED drive circuit for driving an LED device for use in a backlight of a liquid crystal panel, the backlight LED drive circuit comprising: a step-up DC/DC converter for stepping up a DC power voltage based on a PWM signal and supplying a stepped up voltage to an anode side of the LED device; a voltage detector for detecting a feedback voltage based on a voltage at a terminal coupled with a cathode side of the LED device; a PWM control circuit for controlling the PWM signal output to the step-up DC/DC converter so that the feedback voltage becomes a predetermined voltage set as a feedback voltage for illuminating the LED device appropriately; and a PWM stop circuit for stopping the outputting of the PWM signal to the step-up DC/DC converter when the feedback voltage is below a second predetermined voltage set lower than the predetermined voltage, when the PWM control circuit controls the PWM signal so that the feedback voltage becomes the predetermined voltage.