使用反降壓型架構的切換式LED驅動器研製

Design and Implementation of an LED Switching Driver Using Inverse Buck Topology

張宏祥(Hong-Hsiang Chang)

指導教授 ： 歐勝源

國立臺北科技大學/電資學院/電機工程系研究所/碩士(2014年)

https://doi.org/10.6841/NTUT.2014.00665

摘要

本篇論文使用反降壓型切換式LED驅動器完成調光特性與LED短路保護。所研製的切換式LED驅動器主要是利用固定截止時間來調節脈波寬度，將所研製的驅動器以變頻調變控制在連續電流模式或邊界電流模式，且只是利用電阻器與電容器來做設定即可完成所需功能。
近年來為了解決能源消耗與生活空間的問題，一般家庭目前所使用的液晶電視已經由LED取代CCFL。液晶電視所使用的面板中，均為多串LED燈，為了解決各LED燈串上電壓差的問題，本篇文章提出一種反降壓型LED驅動器架構，藉以完成可接受的電流平衡特性，並且解決面板上LED燈串所造成電壓差的問題。在本篇文章中，此反降壓架構是使用固定截止時間的PWM控制IC來實現LED燈串面板的控制。
最後，實驗結果確認可以滿足規格的需求。

關鍵字

脈波寬度調變 ； 調光 ； 電流均衡

並列摘要

This thesis proposes an LED switching regulator using inverse buck topology to achieve dimming improvement and LED string short and dimming short operation and protection. The used pulse width modulation technique is fixed off time adjustment by easily setting the additional elements comprised of a resistor and a capacitor to achieve variable-frequency control under continuous current mode (CCM) or boundary current mode (BCM).
Recently, LED is largely used in LCD TV system to save energy and space in human life instead of cold-cathode fluorescent lamps.In order to solve the problem of voltage deviation in each LED string, this paper provides an LED switch ing regulator to achieve the acceptable current-equalization function, and also solve the problem of voltage deviation in the LCD TV that using multi-string panel construction. In this thesis, the inverse buck topology is used with constant off time control IC to implement a LED string panel control to verify the proposed analysis.
Finally, the experimental results show good confirm and meet the required specification.

並列關鍵字

pulse width modulation ； dimming ； current-equalization

參考文獻

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