升压型白光LED驱动控制器的设计  

Design of boost WLED driver controller

作　　者：杨永良[1] 吴晓波[1] 

机构地区：[1]浙江大学超大规模集成电路设计研究所,浙江杭州310027

出　　处：《机电工程》2010年第9期83-87,共5页Journal of Mechanical & Electrical Engineering

基　　金：国家自然科学基金资助项目(60906012)

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1.5μm 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。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.

关 键 词：白光LED驱动 PWM调光 峰值电流模式 

分 类 号：TN433[电子电信—微电子学与固体电子学]