LED BACKLIGHT DRIVING CIRCUIT AND DRIVING METHOD THEREFOR, AND LIQUID CRYSTAL DISPLAY APPARATUS

摘要

An LED backlight driving circuit and a driving method therefor, and a liquid crystal display apparatus. The LED backlight driving circuit (10) comprises an LED light bar (30) and a power module (20) driving the LED light bar (30). An output end of the LED light bar (30) is separately coupled to a short-circuit protection module (40) and a divider resistor (R0). The short-circuit protection module (40) comprises a comparison unit (41) and a driving unit (42) coupled to the comparison unit (41). Voltages at two ends of the divider resistor (R0) are used as feedback voltages (V1, V2) coupled to the comparison unit (41). The comparison unit (41) is also coupled to a preset first reference voltage (VF1). When a value, by which the feedback voltages (V1, V2) exceed the first reference voltage (VF1), is greater than a preset deviation value, the driving unit (42) controls the power module (20) to be switched off. When the first reference voltage (VF1) is greater than or equal to a maximum brightness of the LED light bar in a normal state, the voltages at the two ends of the divider resistor (R0) are divided. The LED backlight driving circuit (10) can provide a short-circuit protection function when an LED lamp bead is in a short circuit.