Patent ID: 7208886

Claim:
An apparatus for driving Cold Cathode Fluorescent Lamps (CCFLs), comprising: a buck converter coupled to a direct-current power supply; a resonant boost converter connected to the buck converter; one or more CCFLs connected to the resonant boost converter; a starting voltage adjustment circuit connected between the buck converter and the resonant boost converter, for adjusting a starting voltage to the CCFLs according to a temperature of the immediate environment; a feedback loop connected between the CCFLs and the buck converter, for generating voltage signals to control the buck converter; and a PWM (pulse-width modulation) control circuit positioned between the feedback loop and the buck converter, the PWM control circuit producing PWM waves to control the buck converter according to voltage signals received from the feedback loop, the PWM control circuit comprising a comparator and a modulation signal generator, the comparator comprising three inputs and an output, the inputs respectively connecting to the starting voltage adjustment circuit, the feedback loop and the modulation signal generator, and the output connecting to the buck converter.