带有过温保护和自适应调节的LED驱动电路  

LED drive circuit with over-temperature protection and adaptive adjustment

作　　者：夏俊雅[1] 曾以成[1] 崔晶晶[1] XIA Junya;ZENG Yicheng;CUI Jingjing(Department of Microelectronics Science and Engineering,Xiangtan University,Xiangtan Hunan 411105,China)

机构地区：[1]湘潭大学微电子科学与工程系,湖南湘潭411105

出　　处：《太赫兹科学与电子信息学报》2018年第4期729-734,共6页Journal of Terahertz Science and Electronic Information Technology

基　　金：国家自然科学基金资助项目(61471310)

摘　　要：设计了一种带有过温保护和自适应调节功能的发光二极管(LED)恒流驱动电路。该驱动电路主要由过温保护电路和自适应电路组成,过温保护电路用于检测系统的工作温度情况,当系统处于高温时会输出关断信号使电路停止工作;自适应电路在自适应温度范围内通过向恒流模块输入与绝对温度成正比(PTAT)电流来调控LED驱动电流的大小,达到自适应目的。该LED驱动电路将温度自适应与带有滞回功能的过温关断电路巧妙地结合在一起,使得电路简单,性能良好。基于0.5μm CMOS工艺,Spectre仿真结果表明:当系统在0℃~89.6℃变化时,恒流输出波动小于0.57%;在89.6℃~111℃变化时,调控输出电流可调幅度为80 mA;在114℃时,过温保护电路开启,电路停止工作,直到温度降回73.3℃后,LED驱动电路重新开始工作。An Light Emitting Diode（LED） constant current drive circuit with the over-temperature protection and the adaptive temperature regulation is designed. The drive circuit is mainly composed of an over-temperature protection circuit and an adaptive circuit. The over-temperature protection circuit is utilized to detect the operating temperature of the system. When the system is under high temperature, the shutdown signal is output to stop the circuit. The adaptive temperature adjust circuit would input Proportional To Absolute Temperature（PTAT） current to the constant current module to adjust the LED drive current, then the adaptive regulation is achieved. The circuit, combining the temperature adaptive regulation with the hysteresis function of the over-temperature shutdown circuit, is simple, but with high performance. Based on the 0.5 μm CMOS process, Specter simulation results show that when the system temperature changes from 0 ℃ to 89.6 ℃, the constant current output fluctuation is less than 0.57%. When the change is from 89.6 ℃ to 111 ℃, the adjustable output current is 80 mA. When the temperature rises up to 114 ℃, the over-temperature protection circuit is switched on, and the circuit stops working. When the temperature drops back to 73.3 ℃, the LED drives circuit to start work again.

关 键 词：自适应 过温保护 滞回关断 LED驱动 

分 类 号：TN43[电子电信—微电子学与固体电子学]