Light-emitting diode (LED) backlight driving circuit and backlight module

Abstract

The invention discloses a light-emitting diode (LED) backlight driving circuit and a backlight module. According to the LED backlight driving circuit, a voltage conversion unit is used for converting the output voltage of an external power supply into driving voltage required by an LED; an output end of the voltage conversion unit is connected to an anode of the LED and used for supplying the required driving voltage to the LED; a driving unit is used for controlling the voltage conversion unit to realize voltage conversion; a circuit protection unit is connected in series between a cathode of the LED and the driving unit; the maximum allowable power of the circuit protection unit is smaller than power borne by the circuit protection unit when the driving voltage of the LED is directly applied to the circuit protection unit; and a control unit outputs an operation stopping control signal to the driving unit when the circuit protection unit is open-circuited. In the mode, a circuit device can be protected from being damaged, so an LED short-circuit protection function is safe and reliable.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an LED backlight driving circuit and a backlight module. Background technique [0002] The LCD display panel itself cannot generate a light source, and it must use a backlight to project light onto the display panel to generate brightness on the display panel, and the brightness must be evenly distributed to obtain an image display. At present, the backlight source of the LCD display panel is mainly divided into two types: LED and CCFL. Compared with CCFL backlight, LED backlight has the advantages of low power consumption, long life, ultra-thin and good optical characteristics. Therefore, liquid crystal display with white LED as backlight is gradually becoming the development direction of LCD TV. [0003] In order to ensure the performance of the LED backlight module and avoid failure of the LED backlight module to cause the liquid crystal display to fail to display, the...

AI Technical Summary

Problems solved by technology

[0005] Although the MOS tube can protect the LED backlight drive circuit, when the LED backlight drive circuit is working normally, the MOS tube is turned on, and the power loss in the MOS tube is large, and the temperature of the MOS tube is high, which affects its life. The price of MOS tubes is also high, which is not conducive to cost reduction

In addition, when the MOS tube is disconnected, there is still a high voltage on the negative pole of the LED, which will cause certain safety hazards

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