一种高效率白光LED驱动器的设计  

Design of High-Efficiency White-LED Driver

作　　者：张赛[1] 李冬梅[1] 

机构地区：[1]清华大学微电子学研究所,北京100084

出　　处：《微电子学》2007年第3期428-431,共4页Microelectronics

摘　　要：小功率白色LED是便携式电子产品中LCD背光照明的最佳选择,其驱动器可以看作是向LED供电的特殊电源。介绍了一种高效率PFM升压型DC/DC转换器的设计。该转换器可带30 mA负载,输入电平0.8-3 V,输出1.9-3.9 V,无需外接用于启动的肖特基二极管,可在1.2V电压启动;重点对基准电压和振荡器的设计进行分析,采用0.6μm CMOS工艺完成芯片的设计。负载为20 mA时,芯片的工作效率大于80%,电压精度≤±2%,有较大的实用价值。Low power white LED is the best choice for LCD＇ s backlight in portable electronic products. Its driver can be regarded as a special power supply. Design of a high-efficiency PFM boost DC/DC converter is presented, which is capable of sourcing an output current up to 30 mA, with an input range from 0. 8 V to 3 V and an output range from 1.9 V to 3. 9 V. With external inductor and capacitor, it can start-up at 1.2 V without an external Schottky diode. Circuits of voltage reference and oscillator are analyzed in particular. Designed and simulated using 0. 6 μm CMOS process, the device has achieved an efficiency greater than 80% when loading 20 mA and voltage precision better than ±2%, and the time to stabilize output voltage is 1. 813 ms.

关 键 词：白光LED LED驱动器 升压型DC/DC转换器 脉冲频率调制 

分 类 号：TN431.1[电子电信—微电子学与固体电子学]