快速启动双反馈环路LED恒流输出通道设计  

Design of Fast Startup LED Constant-Current Output Channel with Dual Feedback Loop

作　　者：董铸祥[1] 宁宁[1] 于奇[1] 杨晓春[1] 郑志威[1] 曹英帅[1] 

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,成都610054

出　　处：《微电子学》2013年第2期179-182,共4页Microelectronics

基　　金：中央高校基本科研业务费专项资金资助项目(ZYGX2010J040)

摘　　要：为了解决LED恒流驱动输出电流不稳的问题,提出采用双反馈环路的通道结构。在此基础上,设计了采用分段模式的快速启动电路,可极大地提升通道的开启速度。基于0.25μmBCD工艺,完成HSPICE仿真。结果显示,该系统的外环路增益为83dB,相位裕度为80o,通道间电流互不影响。当电流在5～45mA范围内变化时,快速启动电路正常工作,通道的开启时间仅为4ns,开启速度较传统结构有显著提升。该输出通道已成功应用于LED恒流驱动中。To solve the problem of output current instability in LED constant-current driver, a channel structure with dual feedback loop was proposed. Based on the structure, a fast startup circuit using segmentation mode was designed to enhance turn-on speed of the channel. The circuit was simulated with HSPICE based on 0. 25/,m BCD process. Results showed that the system had an outer loop gain of 83 dB, and a phase margin of 80~ with no interaction of currents between channels. The fast startup circuit operated properly when channel current varied from 5 mA to 45 mA. The turn-on time of the channel was only 4 ns, which was a significant improvement, compared to the traditional structure. The proposed output channel has been applied to LED constant-current driver successfully.

关 键 词：LED驱动 恒流输出通道 双反馈环路 快速启动电路 

分 类 号：TN433[电子电信—微电子学与固体电子学]