摘要
LED结温是表征其性能的关键参数之一,基于正向电压-结温关系进行结温检测被认为是目前最准确的方法。在研究了LED正向电压随结温变化关系的基础上,通过小电流驱动LED监测正向电压法检测结温平衡以获取结温的准确值,采用大电流触发连续采样获取结温变化前的大电流下正向电压值,并对其线性拟合,从而获得大电流下的LED正向电压-结温关系式。应用该方法对同一LED不同电流和不同LED同一电流的正向电压-结温关系进行多次检测,实验结果表明:拟合得到的正向电压-结温关系式准确、可重复性高,K值的相对标准偏差小于0.7%,结温计算的不确定度估计值小于0.5℃。该方法为基于正向电压法的结温精确检测提供了一种新的参考。
LED junction temperature is one of the key parameters to represent its performance. The method of de- tecting junction temperature based on the relation between forward voltage and junction temperature is considered to be the most accurate one. After studying the changing relation between forward voltage and junction tempera- ture, a method for testing the balance of junction temperature by monitoring LED forward voltage under small driving current was used to get accurate junction temperature, a method of high current triggering continuous sampling was adopted to acquire the forward voltage under high driving current without junction temperature changing. Then the equation representing the relation between LED forward voltage and junction temperature can be achieved by linear fitting the different forward voltage at different junction temperature. By using the method, relations between forward voltage and junction temperature of same LED different current and different LED same current were detected for several times. The experiment result shows that the linear fitting equation has high accuracy and repeatability. The relative standard deviation of factor K is less than 0.7% and the uncertainty of calcu- lated junction temperature is less than 0.5℃ .The method provides a new reference for precision measurement of junction temperature based on forward voltage method.
出处
《贵州大学学报（自然科学版）》
2016年第2期79-83,共5页
Journal of Guizhou University:Natural Sciences
基金
福建省科技重点项目(2013H0039)
福建省教育厅科技项目(JA15457
JA15439
JA13277)
关键词
正向电压-结温关系
大电流
高速采样
线性拟合
forward voltage-junction temperature relation
high current
high-speed sampling
linear fitting
