LED BACKLIGHT DRIVING CIRCUIT, LCD DEVICE, AND METHOD FOR DRIVING THE LED BACKLIGHT DRIVING CIRCUIT

摘要

A light emitting diode (LED) backlight driving circuit includes an LED light bar, a power supply that drives the LED light bar to light, a short-circuit protection unit, and a divider resistor. An output end of the LED light bar is coupled to the short-circuit protection unit and the divider resistor. The short-circuit protection unit includes a comparing unit and a driving unit coupled to the comparing unit. Voltage of two ends of the divider resistor is regarded as a feedback voltage, and the feedback voltage and a first reference voltage are input to the comparing unit. When a difference value of the first reference voltage subtracted from the feedback voltage is greater than a preset deviation value; the driving unit controls the power supply to turn off. When brightness of one normal LED light bars reaches a maximum, the first reference voltage is greater than or equal to voltage of two ends of the divider resistor corresponding to the one normal LED light bar.

主权项

1. A light emitting diode (LED) backlight driving circuit, comprising:
an LED light bar; a power supply that drives the LED light bar to light; a short-circuit protection unit comprising a comparing unit and a driving unit coupled to the comparing unit; and a divider resistor; wherein an output end of the LED light bar is coupled to the short-circuit protection unit and the divider resistor, voltage of two ends of the divider resistor is regarded as a feedback voltage, and the feedback voltage and a first reference voltage are input to the comparing unit; when a difference value of the first reference voltage subtracted from the feedback voltage is greater than a present deviation value, the driving unit controls the power supply to turn off; when brightness of one normal LED light bars reaches a maximum, the first referenced voltage is greater than or equal to voltage of two ends of the divider resistor corresponding to the one normal LED light bar.