Light-emitting diode (LED) backlight drive circuit and liquid crystal display device

Abstract

The invention discloses a light-emitting diode (LED) backlight drive circuit and a liquid crystal display device. The LED backlight drive circuit comprises an LED light bar and a drive chip which is coupled with the LED light bar. The drive chip is provided with a protection pin which can control the drive chip to be in a protection state when a preset voltage range is exceeded. An input under-voltage protection module is coupled between a power input end of the LED light bar and the protection pin. An output overvoltage protection module is coupled between a power output end of the LED light bar and the protection pin. The input under-voltage protection module outputs first control voltage which exceeds the preset voltage range to the protection pin when the power input end of the LED light bar is in an under-voltage state. The output overvoltage protection module outputs second control voltage, which exceeds the preset voltage range, to the protection pin when the power output end of the LED light bar is in an overvoltage state. According to the LED backlight drive circuit, the input under-voltage protection module and the output overvoltage protection module can share the same protection pin, and therefore the number of occupied pins of the drive chip is reduced.

Description

technical field [0001] The invention relates to the field of liquid crystal display, and more specifically relates to an LED backlight driving circuit and a liquid crystal display device. Background technique [0002] Most existing liquid crystal display devices use LEDs as backlight sources, and multiple LEDs are connected in series to form a light bar. If there are multiple light bars, they can also be arranged in parallel. The driving of the LED light bar is controlled by the driver chip. In order to ensure the safe and reliable operation of the light bar, the driver chip generally provides input under-voltage protection and output over-voltage protection. However, in the prior art, the protection signals of the two protection mechanisms Two pins of the driver chip are respectively occupied, and occupying too many pins is not conducive to further expanding the functions of the driver chip. Contents of the invention [0003] The technical problem to be solved by the pre...

AI Technical Summary

Problems solved by technology

The driving of the LED light bar is controlled by the driver chip. In order to ensure the safe and reliable operation of the light bar, the driver chip generally provides input under-voltage protection and output over-voltage protection. However, in the prior art, the protection signals of the two protection mechanisms Occupies two pins of the driver chip respectively, occupying too many pins is not conducive to further expanding the function of the driver chip

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