基于高边电流检测驱动LED  

The constant current driving for LED with high side current sense topology

作　　者：陈英[1] 杨瑜[1] 

机构地区：[1]四川大学锦江学院,四川彭山620860

出　　处：《自动化与仪器仪表》2011年第5期124-125,128,共3页Automation & Instrumentation

摘　　要：研究了一种采用高边电流检测的滞环控制LED恒流驱动芯片。基于0.5um5V/18V/40VCDMOS工艺,运用Hspice工具对电路进行仿真,仿真结果显示:在4.5V～28V电源电压范围内,-40℃～+125℃工作温度范围内,电路可为LED提供恒定的350mA驱动电流,LED驱动电流为滞环变化的三角波,最大误差为6.2%。通过调节外部信号DIM的占空比可以调节LED的亮度。A chip which is used in the high-side current sensing topology to drive white LED with a constant current is studied. Based on the 0.5urn 5V/18V/40V CDMOS process, the simulation by using Hspice shows that the chip can provide a driving current of 350mA for LED when the power supply changes from 4.5V-28V, with working temperature ranged from -40^oC to ＋125 ^oC. The LED driving current is hysteresis, and the precision of constant current can be controlled within the range of 6.2 %. The duty cycle of the signal DIM can be adjusted to realize lightness regulation of LED.

关 键 词：高边电流检测 滞环控制 PWM调光 

分 类 号：TN364.2[电子电信—物理电子学]