一种高精度恒流LED驱动芯片的研究与设计
发布时间：2019-06-14 05:55
【摘要】：在全球变暖、资源愈加匮乏的环境大背景下,绿色环保成为了备受瞩目的热点话题。在照明应用的领域中,LED以其高效率、节能的特点掀开了人类照明历史上的崭新篇章。为了获得更稳定的LED照明,人们对LED驱动以及应用的研究从来没有停止过。本文设计了一款高精度恒流LED驱动芯片,主要应用于日常的小功率照明中。区别于传统的开环恒流固定关断时间的模式,该芯片采用闭环反馈回路恒流,能够动态调节关断时间,具有更高的恒流精度。为了满足低功耗的要求,芯片采用了源极驱动的方式,减小了静态电流,不仅降低了功耗更提高了芯片的效率。对于芯片内部的模块设计,在完成功能的同时尽量减少器件的使用,使芯片具有小体积、低成本的特点。该芯片采用BUCK结构,输入电压范围为167VAC~265VAC,满足日常照明市电输入的要求;芯片的输出为10~98V;根据设计,输出电流的峰值为90mA,平均电流为60mA,可以满足日常照明LED的驱动要求。通过闭环恒流控制的实现,芯片的恒流精度可以达到±3%。本论文首先简单介绍了LED的一些特性,如发光原理和发光效率等,接着从LED驱动芯片设计的基础知识着手,介绍了开关电源的常用拓扑及调制模式等内容,然后对芯片的整体功能及闭环恒流的实现原理进行了描述,通过对子模块电路的设计和仿真介绍了该芯片的内部结构。最后,对芯片的外围参数进行了设计,在此基础上对电路进行了相关仿真并做出了结论描述,仿真结果满足设计要求。
[Abstract]:Under the background of global warming and increasingly scarce resources, green environmental protection has become a hot topic. In the field of lighting application, LED has opened a new chapter in the history of human lighting because of its high efficiency and energy saving. In order to obtain more stable LED lighting, the research on LED driver and application has never stopped. In this paper, a high precision constant current LED driver chip is designed, which is mainly used in daily low power lighting. Different from the traditional open-loop constant current fixed turn-off time mode, the chip adopts closed-loop feedback loop constant current, which can dynamically adjust the turn-off time and has higher constant current accuracy. In order to meet the requirements of low power consumption, the chip adopts the way of source drive, which reduces the static current, not only reduces the power consumption, but also improves the efficiency of the chip. For the internal module design of the chip, the use of the device is reduced as much as possible while the function is completed, so that the chip has the characteristics of small volume and low cost. The chip adopts BUCK structure, the input voltage range is 167 VAC 鈮，
本文编号：2499164
[Abstract]:Under the background of global warming and increasingly scarce resources, green environmental protection has become a hot topic. In the field of lighting application, LED has opened a new chapter in the history of human lighting because of its high efficiency and energy saving. In order to obtain more stable LED lighting, the research on LED driver and application has never stopped. In this paper, a high precision constant current LED driver chip is designed, which is mainly used in daily low power lighting. Different from the traditional open-loop constant current fixed turn-off time mode, the chip adopts closed-loop feedback loop constant current, which can dynamically adjust the turn-off time and has higher constant current accuracy. In order to meet the requirements of low power consumption, the chip adopts the way of source drive, which reduces the static current, not only reduces the power consumption, but also improves the efficiency of the chip. For the internal module design of the chip, the use of the device is reduced as much as possible while the function is completed, so that the chip has the characteristics of small volume and low cost. The chip adopts BUCK structure, the input voltage range is 167 VAC 鈮，
本文编号：2499164
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