| 摘要 |
It is disclosed about a LCD backlight inverter for controlling the overvoltage with a stable output in respect to the fluctuation of an input voltage and preventing an effect to a feedback controlling block in opening a lamp used as a backlight. An overvoltage protection circuit of the LCD backlight inverter comprises a first comparing block for comparing the dimension of a feedback signal with the dimension of a first reference voltage, wherein the feedback signal detects the dimension of the voltage according to on/off status of the backlight lamp in the rear end; a second comparing block for comparing the dimension of the voltage divided in the overvoltage protection circuit with the dimension of a second reference voltage; and a switching controlling block for receiving output signals from the first and second comparing blocks and controlling on/off status of the buck switch according to corresponding comparison signals. The output voltage can be constantly controlled at any time according to the change of the input voltage by using means for controlling the overvoltage in opening the lamp, and also an effect about an abnormal noise of the feedback signal can be minimized in the normally operating status.
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