本文提出一種LED驅動電路，用於新興的照明系統或背光模組。驅動電路採用推挽式（push-pull）升壓電路，以驅動多組串並聯LED，在電流控制方面，利用回授電壓控制電流源，以達成LED定電流驅動之目的，並利用脈波寬度調變（PWM）技術進行LED亮度調節。其調光範圍可從0（全暗）至100%（全亮），其好處在於調光時不改變流經LED的電流大小，僅改變其開關導通週期，使LED在每個脈波寬期間保持相同的電流大小，因此在調節亮度時期光譜保持不變，不會有色彩偏移的現象產生。本文實際製作一13.3吋LED背光面板，並實際量測LED電流的精確度與匹配度，以驗證驅動電路的可靠性，實驗結果與理論預測相當接近。

A LED driving circuit used in new lighting systems and backlighting modules is proposed. This LED driving circuit uses Push-Pull boost converter to drive a combination of parallel and series LEDs. As for current control, LED driving circuit is employed as a constant current by a feedback voltage control current source. PWM dimming control is used to adjust LED brightness from 0(dark) to 100% (full brightness). Remaining same brightness LED through dimming makes no color shift and without affecting the current through LED. To prove the utilization of the driving circuit, a 13.3 inch LED backlighting panel is examined has been made. The performance including current control and sharing accuracy of LED have been measured in this experiment. The experimental result is very close to the theoretical predictions.

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