一款高恒流精度Buck型LED驱动芯片的设计

发布时间：2018-06-07 21:00

本文选题：LED驱动 + Buck　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：随着节能减排、绿色经济和循环经济的发展深入,我国将逐步禁止白炽灯的使用。LED能耗非常低节能效果明显,其能耗只是传统白炽灯光照源的10%左右,是节能灯的25%左右。LED不仅节能效果明显,而且具有更宽的光机色域、更高色彩饱和度,应用范围更广。LED的平均使用寿命长达60000小时以上,其寿命远远长于传统的照明源。LED具有节能效果好、应用范围广和使用寿命长等优点成为下一代照明主要照明源是大势所趋。为了使LED在工作过程中能稳定和照明亮度保持不变,因此需专门的驱动芯片来控制保证流过LED的电流恒定。本论文主要是针对小功率LED灯设计一款低成本高恒流精度的驱动芯片。本产品是应用于Buck型LED驱动系统,支持全电压输入(交流85V-265V),可大大降低系统成本。芯片采用PSM控制并且可以根据负载的轻载重载情况调整输出占空比,在保证高的输出效率的同时又降低了输出纹波。系统在满载情况下输出效率可以达到90%以上,且输出的恒流精度在±1%的误差范围内。本论文首先对的LED的现状、基本特性和应用做了简单介绍。然后介绍了LED的主要的驱动方式、驱动框架、拓扑结构和主要的控制方式,并针对本系统的应用详细的分析了在不同工作模式下的工作情况。其次对于本系统的工作原理和系统的结构功能做了详细的分析。此外介绍了芯片内部各个主要模块的基本功能,并根据模块功能设计了电路,并在CSMC的0.8um 40V BCD工艺设计下对于电路进行了仿真和对于仿真结果做了分析。最后针对系统进行了系统级的仿真,并结合仿真结果来评估了芯片和系统的性能,芯片的各项指标均符合设计要求。
[Abstract]:With the development of energy saving and emission reduction, green economy and circular economy, our country will gradually ban the use of incandescent lamps. The energy consumption of LED is very low, and the energy consumption is only about 10% of the traditional incandescent light source. About 25% of the energy-saving lamps. Led not only energy saving effect, but also with a wider light machine color gamut, higher color saturation, a wider range of applications. Led average service life of more than 60000 hours, Its life is far longer than the traditional lighting source. Led has good energy saving effect, wide application range and long service life to become the main lighting source for the next generation of lighting is the general trend. In order to keep the LED stable and illumination brightness constant during the working process, a special drive chip is needed to control the current that flows through the LED. In this paper, a low cost and high constant-current drive chip is designed for low power LED lamp. This product is used in Buck LED drive system, supporting full voltage input (AC 85V-265 V), can greatly reduce the cost of the system. The chip adopts PSM control and can adjust the output duty cycle according to the light load and heavy load, which can ensure high output efficiency and reduce the output ripple at the same time. The output efficiency of the system can reach more than 90% under the condition of full load, and the output accuracy of constant current is within 卤1% error range. This paper first introduces the current situation, basic characteristics and application of LED. Then the main driving mode, driving frame, topology structure and main control mode of LED are introduced, and the working conditions under different working modes are analyzed in detail for the application of this system. Secondly, the working principle of the system and the structure and function of the system are analyzed in detail. In addition, the basic functions of each main module in the chip are introduced, and the circuit is designed according to the module function. The circuit is simulated under the 0.8um 40V BCD process design and the simulation results are analyzed. Finally, the system-level simulation is carried out for the system, and the performance of the chip and the system is evaluated based on the simulation results. All the specifications of the chip are in line with the design requirements.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM923.34

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