AnalogicTech AAT1409八路LED背光驱动方案
AnalogicTech公司的AAT1409是高度集成高效率的八路LED背光驱动器，集成了升压转换器（输出高达45V）和高频PWM调光。AAT1409的VIN范围4.5V 到 5.5V / 5.0V 到26.0V，每路的电流可编程达45mA，总输出电流360mA，可支持881个白光LED。效率高达92%，每路电流精度±2%，路间电流匹配±2%，调光范围1,000:1，主要用在监视器，笔记本电脑，手提TV，手提DVD播放器和白光LED背光。本文介绍了AAT1409主要特性，功能方框图，典型应用电路图以及AAT1409IMK评估板电路图和采用主从配置的288个LED应用电路。
8 Channel LED Backlight Driver with Integrated Boost and High Frequency Direct PWM Dimming
The AAT1409 is a highly integrated, high efficiency LED backlight solution for notebook computers, monitors and portable TVs. The device operates from DC inputs, cigarette lighter adapters, or multi-cell Li-ion batteries over the 4.5V to 26V voltage range.
An integrated boost (step-up) converter provides up to 45V output for driving series LEDs. Eight precision current sinks are programmed up to 45mA per string through one external RSET resistor, supporting up to 881 white LEDs at 360mA total output current.
LED strings may be disabled or operated in parallel for increased drive capability. The boost output voltage is set by the LED string with the highest voltage requirement, allowing a wide range of LED characteristics.
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