升压型白光LED驱动控制器的设计*

作者：杨永良，吴晓波* 日期：2010-11-16/span> 浏览：3701 查看PDF文档

升压型白光LED驱动控制器的设计*
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杨永良，吴晓波*
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（浙江大学 超大规模集成电路设计研究所，浙江 杭州 310027）
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摘要：为使白光LED能适应宽电源电压范围的工作,并具有高调光比和良好的调光特性，提出了一种白光LED驱动电路控制器。设计了一个具有高线性调整率的带隙电压基准为内部模块提供稳定的参考电压，保证了系统在宽工作电压范围内的稳定工作；为避免模拟调光造成的色偏，采用了数字PWM调光模式，实现了无色偏调光功能；此外，为减少LED在系统启动时承受的瞬时电流，引入了软启动电路，延长了器件的寿命。控制芯片在1.5 μm BCD工艺下设计与完成。利用该器件构成应用电路的实测结果表明，所提出的LED控制器能够在6 V~15 V输入电压范围内稳定驱动一个总负载电流为150 mA的3×7白光LED阵列，并能实现很高的PWM数字调光比，达到了预期的设计要求。
关键词：白光LED驱动；PWM调光；峰值电流模式
中图分类号：TN433
文献标识码：A文章编号：1001-4551(2010)09-0083-05

Design of boost WLED driver controller
YANG Yongliang, WU Xiaobo
(Institute of VLSI Design, Zhejiang University, Hangzhou 310027, China)
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Abstract: To ensure the wide supply voltage adaptability of white lighting LED as well as the high dimming ratio and performance, a white LED driver controller was proposed. A bandgap voltage reference with high linear regulation was introduced into the chip to offer a stable reference voltage to inner modules of the system, which guaranteeed its stable work over wide voltage range. To avoid the color drifting originated from analog dimming, a digital PWM dimming was proposed and realized. In addition, a soft start circuit was designed to inhibit the transient current during the starting periods of system, which prolong the lifetime of the devices. The chip was designed and fabricated in 1.5 μm BCD technology. An actual driver circuit was constituted by the chip to drive a 3×7 white LED array with a total load current of 150 mA. The test results show that it drives the array steadily over the supply voltage range from 6 V to 15 V. And a high PWM dimming ratio is achieved. All the test results meet the design specifications well.
Key words: white LED driver; pulse width modulation(PWM) dimming; peak current mode control