全集成的可调光白光LED驱动芯片的设计  

The Design of Fully Integrated Dimmable White LED Drive Chip

作　　者：杨媛[1] 宋征华[1] 高勇[1] 

机构地区：[1]西安理工大学自动化与信息工程学院,陕西西安710048

出　　处：《西安理工大学学报》2010年第1期43-47,共5页Journal of Xi'an University of Technology

基　　金：陕西省自然科学基金资助项目(2009JQ8014)

摘　　要：为了实现LED驱动电路的无色偏高集成度要求,提出一种新型全集成的可调光白光LED驱动芯片。该芯片在无需外部电感、电容的同时完成了白光LED的驱动,并实现了片内集成的调光功能,可用于需要高集成度或避免电磁干扰的场合;芯片采用脉冲宽度调制(PWM)的方式来实现调光功能,在获得大范围亮度调节的同时可以避免色彩偏移现象的发生;芯片内部采用一种无外置电容的低压差线性稳压器(LDO)作为功率变换单元,具有较高的稳定性和转换速度。采用CSMC0.5μm混合信号模型进行了仿真,结果表明,该芯片可以提供占空比在0到100%之间固定变换的峰值为350 mA的输出电流,实现了大范围的亮度调节功能。In order to satisfy the requirement of high integration and avoid the color shift of LED driver,a novel type of fully integrated white Light Emitting Diodes（LED） drive chip is proposed.The chip can accomplish LED driving and on-chip dimming without external capacitor or inductor,so that it can be easily used in any application environment where a high integration or resistance to electromagnetic interference（EMI） is required.Pulse Width Modulation（PWM） has been used in the dimming module,and a wide dimming range without color shift can be obtained.In the chip a capacitor-less Low Dropout Linear Voltage（LDO） Regulator is used as the power conversion circuit which can possess high stability and conversion speed.The chip is simulated with CSMC 0.5 μm mixed signal models,and the results show that a 350 mA peak output current with the duty ratio changing from 0 to 100% can be achieved to realize luminance control of wide range.

关 键 词：发光二极管 驱动芯片 脉冲宽度调制 占空比 

分 类 号：TN432[电子电信—微电子学与固体电子学]