1、 I 摘摘 要要 随着能源危机的加剧,绿色高效的照明系统得到了人们的广泛重视。我国在 1996 年也推出了“中国绿色照明工程“,旨在我国发展和推广高效照明器具,逐步 替代传统的低效照明电光源,节约照明用电。冷光源 LED 以其高效率、低功耗、低 电压驱动、使用寿命长以及节能环保等优点,引起了全世界的广泛关注,被越来越 多的应用于各种照明场合, 在可预见的将来将有可能进入一般照明市场以替代传统 的热照明方案成为新一代照明光源。因此,研究针对冷光源 LED 驱动电路的研究设 计有很重要的意义。 本文基于高性能、低功耗的 8 位 AVR 微处理器研究冷光源照明技术。 采 用单通道输出的 LED 恒流
2、驱动器驱动高达 1 安培的沈入电流(sink current) ,并 可透过调整参考输入电流( REF I)来任意设定输出电流的大小。 微调或使能偏压电压 可校正 LED 间的亮度不一或实现多颗 LED 间整体亮度同时调整。采用 LNK306 来替 代输出电流小于 360mA 的所有线性及电容降压式非隔离电源。 其系统成本与所替代 的电源相等,但性能更好、效率更高。采用 AD590 温度检测,适用于 150以下、 目前采用传统电气温度传感器的任何温度检测应用。 低成本的单芯片集成电路及无 需支持电路的特点,使它成为许多温度测量应用的一种很有吸引力的备选方案。应 用 AD590 时,无需线性化电
3、路、精密电压放大器、电阻测量电路和冷结补偿。 关键词:关键词:LED 恒流驱动 II AbstractAbstract As the aggravation of energy crisis,green and efficient light system gets more and more attentionIn 1 996,China launched“China Green Lighting Project ,which was in order to develop and promote high-efficient lighting apparatuses,gradually s
4、ubstitute the traditional low-efficient lighting apparatuses, and save lighting electricity Power white LED has aroused world wide interest because of its high efficiency,low power loss,low drive voltage,long service life,energy-conversation and other advantages,to be applied in many kinds of illumi
5、nance situationIn the foreseeable future,power white LED may enter the common lighting market to displace the traditional illuminance methods and become the new generation lighting source So, it has the very vital significance to research the driving circuit of power white LED Based on high-performa
6、nce, low-power 8-bit AVR microcontrollers study cold-light illumination technology. Single-output LED Driver drive up to 1 Amp sink current (sink current), and can be arbitrarily set the size of the output current by adjusting the reference input current (IREF). Fine-tuning, or to enable the bias voltage can be corrected brightness varies between the LED or the overall brightness of the LED at the same time to adjust. The adopted LNK306 to replace