廣輸入範圍控制非隔離式之 降壓型功率因素校正發光二極體驅動晶片設計

Abstract

LED(Light Emitting Diodes)是最佳節省發光功率的解決方案之一。未來世界各國會慢慢淘汰白熾燈而轉而使用LED。所以LED驅動IC的研發就變得格外的重要。本文提出了一種非隔離式功率因數校正功能之降壓型LED驅動IC，可以應用於通用輸入電壓從90Vac到264Vac，亦可兼具功率因數校正(PFC)功能，其功率因數(Power Factor, PF)可達到大於0.9以上，符合美國能源之星相關規範。本論文模擬結果，在全範圍市電輸入從90Vac到264Vac，電流都能控制在定電流，總諧波失真(Total Harmonic Distortion, THD)可控制在12.5%以內，最小可達11.18%，功率因數最高可達0.99，最高效率可達94.71%。

LED (Light Emitting Diodes) is one of the best solution of power saving in light. In the future, the world market will gradually phase out the use of incandescent lamps and use LEDs to replace those. Therefore, the research and development related to LED driver IC become particularly important. Recently, non-isolated buck PFC LED driver IC is proposed so that it can be applied to universal input voltage from 90Vac to 264V. Moreover, the power factor (PF) can be higher than 0.9 to meet the requirement of US energy Star specifications. The proposed technique in this thesis can achieve high efficiency and high accuracy at the same time. Besides, THD is controlled within 12.5% and its minimum value is 11.18% in the entire universal input voltage range. Maximum PF and efficiency are 0.99 and 94.71%, respectively.