›› 2012, Vol. 25 ›› Issue (1): 1-.

• 论文 •    下一篇

一种滞环恒流LED驱动电路的电流采样电路

孙正旻,陈后鹏,王倩,罗胜钦,宋志棠   

  1. (1.同济大学 电子与信息工程学院,上海 201804;2.中国科学院上海微系统与信息技术研究所 信息功能材料国家重点实验室,上海 200050)
  • 出版日期:2012-01-15 发布日期:2012-01-10
  • 作者简介:孙正旻(1987—),男,硕士研究生。研究方向:集成电路工程。
  • 基金资助:

    国家集成电路重大专项基金资助项目(2009ZX02023-003);国家重点基础研究发展计划基金资助项目(2007CB935400,2010CB934300,2011CB309602,2011CB932800);国家自然科学基金资助项目(60906004,60906003,61006087,61076121);上海市科委基金资助项目(09QH1402600,1052nm07000)。

A Current Sensing Circuit for High-power LED Driver Using Hysteresis Current Control

 SUN Zheng-Min, CHEN Hou-Peng, WANG Qian, LUO Sheng-Qin, SONG Zhi-Tang   

  1. (1.School of Electronics and Information Engineering,Tongji University,Shanghai 201804,China;
    2.State Key Lab of Information Function Material,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China)
  • Online:2012-01-15 Published:2012-01-10

摘要:

针对滞环恒流大功率LED驱动芯片,提出一款高性能电流采样电路。该电路采用高压工艺,可承受最高达40 V的输入电压。通过分析滞环控制的特点,采用串联电阻采样技术,结合匹配电流源结构,在保证响应速度和采样精度的同时,降低了电路的复杂度。电路中加入输入电压补偿电路,进一步提高了恒流控制的精度。在Cadence下的仿真结果表明,电路可在800 kHz的频率下正常工作,采样精度达99.78%;当电压从15 V变化至35 V时平均负载电流误差为0.81%;输出电压范围为0~5 V。

关键词: 恒流控制;高压工艺;匹配电流源;电压补偿

Abstract:

A high-performance current sensing circuit for the high-power LED driver using current control is proposed.It is a high-side current sensing circuit using high voltage process and can withstand up to a 40 V input voltage.By analyzing the characteristics of hysteresis control and using the series-sense resistor sampling technology and matched current source structure,the circuit reduces the complexity while ensuring the response speed and sampling precision.An input voltage compensation circuit is also added to improve the precision of current control.The simulation results in Cadence show that the circuit can work correctly when the operating frequency is 800 kHz.The current sensing accuracy can be up to 99.78%.When the input voltage changes from 15 V to 35 V,the average load current error is as small as 0.81%.The output voltage ranges from 0 V to 5 V.

Key words: current control;high voltage process;matched current source;voltage compensation

中图分类号: 

  • TN432