一种LED灯串故障自检测电路的设计与实现
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摘要
LED背光模组因其具有诸多优势已经成为液晶显示器背光方式的主要选择,而在实际应用当中,若某串LED故障,液晶显示器就会出现暗线,导致亮度均匀性不能满足要求。为了保证液晶显示器的亮度均匀性和后期的维修效率,LED灯串需具备故障自检测的能力。本文设计了一种基于DSP的LED背光模组中灯串故障自检测电路,以546mm(21.5in)液晶显示器的直下式LED背光模组为例,设计了灯板、驱动板的具体硬件电路,利用CCS3.1开发工具,C语言编写软件控制逻辑。自检测结果表明:该电路可有效的对LED灯串进行故障自检测,满足了设计的要求。
LED backlight module has become the main choice of LCD backlight mode because of its many advantages.But in practical application,if a LED string faults,the LCD will appear dark line,resulting in the brightness uniformity cant meet the requirements.The LED string must have the ability of fault self-detection in order to ensure the brightness uniformity of the LCD and the later maintenance efficiency.A self-detection circuit of the LED string in the LED backlight module based on DSP was designed.Taking the direct-down LED backlight module of 546 mm(21.5 in)LCD as an example,the specific hardware circuits of the LED board and driving board were designed.The software control logic was written by C language using the CCS 3.1 development tool.The self-detection results show that this circuit can detect the fault of the LED string effectively and meet the design requirements.
LED backlight module has become the main choice of LCD backlight mode because of its many advantages.But in practical application,if a LED string faults,the LCD will appear dark line,resulting in the brightness uniformity cant meet the requirements.The LED string must have the ability of fault self-detection in order to ensure the brightness uniformity of the LCD and the later maintenance efficiency.A self-detection circuit of the LED string in the LED backlight module based on DSP was designed.Taking the direct-down LED backlight module of 546 mm(21.5 in)LCD as an example,the specific hardware circuits of the LED board and driving board were designed.The software control logic was written by C language using the CCS 3.1 development tool.The self-detection results show that this circuit can detect the fault of the LED string effectively and meet the design requirements.
引文
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[2]李德君,刘刚,吕国强,等.直下式LED背光模组的超薄设计[J].液晶与显示,2014,29(6):1101-1105.LI D J,LIU G,LV G Q,et al.Ultra-thin design of direct-lit backlight unit[J].Chinese Journal of Liquid Crystals and Displays,2014,29(6):1101-1105.(in Chinese)
[3]李鹏飞.基于SM320F2812SPI总线的扩展EEPROM设计[J].电子世界,2013(10):137.LI P F.Extended EEPROM design based on SM320F2812SPI bus[J].Electronics World,2013(10):137.(in Chinese)
[4]DIERBERGER K.Gate drive design for large die MOSFETs[R].Application Note APT9302,1993.
[5]黄静,何青.基于功率MOS管恒流源电路的研究[J].电子学报,2014,29(1):43-47,51.HUANG J,HE Q.The research of constant current source circuit based on VMOS[J].Journal of Electric Power,2014,29(1):43-47,51.(in Chinese)
[6]DSP实验室.软件开发工具CCS的使用[M].北京:北京交通大学电子学院,2005.DSP Laboratory.Use of CCS Software Development Tool[M].Beijing:School of Electronic and Information Engineering,Beijing Jiaotong University,2005.(in Chinese)