| 摘要 |
A method and an apparatus for driving a lamp are provided to supply an EPWM(External Pulse Width Modulation) signal inputted from the outside selectively according to the duty ratio of the EPWM signal inputted from the outside or an IPWM(Inner Pulse Width Modulation) signal generated from an IPWM generator, thereby stably driving backlight by generating a stable AC(Alternating Current) driving signal by using the EPWM signal or the IPWM signal with a stable duty ratio. A method for driving a lamp comprises the following steps of: generating a first PWM(Pulse Width Modulation) signal; generating a second PWM signal; detecting a duty ratio of the first PWM signal; and outputting selectively the first PWM signal or the second PWM signal according to the duty ratio of the first PWM signal. A method for detecting the duty ratio of the first PWM signal comprises the following steps of: integrating the first PWM signal to convert the first PWM signal into a chopping wave; and converting the amplitude of the chopping wave into the DC(Direct Current) level of the duty ratio and outputting the converted chopping wave.
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