本論文之研究範疇為液晶顯示器背光電源之分析與設計，首先提出一種結合壓電變壓器驅動冷陰極管之半橋諧振換流器，並利用轉導控制策略完成穩定冷陰極管驅動電流與燈管之功率及亮度。其次，壓電變壓器之溫昇將會造成諧振換流器輸出電壓與電流極大之變化，因此，本文利用轉導控制策略，藉由擷取壓電變壓器初級側與次級側信號，輸入除法器計算壓電元件因溫度所造成諧振頻率與之偏移量與轉導之變化量，進而藉由類比除法器輸出一電壓準位，調變電壓控制振盪器之輸出頻率，追蹤壓電諧振換流器合適之操作頻率，進而穩定冷陰極管驅動電流與亮度。本文中將說明主電路架構與控制電路之分析，同時提供一設計實例並藉由實驗結果驗證所提之壓電諧振換流器轉導控制策略的正確性。
其次，本文利用諧波近似與諧波平衡程序建立壓電諧振換流器之小信號動態方程式，並根據此動態方程式設計回授補償器。本文中將說明主電路架構與回授補償器之小信號動態分析，同時提出系統補償設計實例並加以分析，最後藉由實測結果驗證所提之壓電諧振換流器補償策略的正確性。
再者，本文提出一種結合串聯諧振直流-直流轉換器與脈衝寬度調光相移技術，完成19吋紅綠藍發光二極體背光模組之驅動。首先，串聯諧振直流-直流轉換器作為高功率發光二極體陣列之驅動電源，因此，串聯諧振轉換器之零電壓切換功效，可有效降低電源轉換器之電磁干擾雜訊。其次，由於串聯諧振直流-直流轉換器在空載操作時穩壓效果不佳，因此，本文利用相移式脈衝寬度調光技術改善上述之缺陷。再者，為了完成背光模組白平衡與亮度穩定之目的，本文利用磁滯控制方式作為數位訊號處理器之調光演算法，藉此改善一般調光演算法，採用數位比例-積分補償器其軟體流程過於複雜之缺陷。本文中將說明串聯諧振直流-直流轉換器與相移式脈衝寬度調光技術之設計，同時並提出一設計實例加以分析，最後藉由實測結果驗證所提光學回授補償之可行性。

The object of this dissertation is the analysis and design of backlight power supplies for liquid crystal displays (LCDs). A half-bridge (HB) resonant inverter with a piezoelectric transformer (PT) for driving a cold cathode fluorescent lamp (CCFL) backlight module is proposed and analyzed. The trans-admittance of the PT-CCFL combination network is measured to track the operating frequency for the HB resonant inverter, which may be varied due to the temperature rise of PT. The lamp driving current and power can thus be remained almost constant in a wide temperature range. Experiments show that the observed result matches the theoretical analyses.
The feedback loop design of the discussed PT-based HB resonant inverter is presented to stabilize the CCFL driving current and luminance by tracking the operating frequency. The dynamic equations and the small-signal model of the presented inverter system are established by using the harmonic approximation and harmonic balance procedures. The complete mathematical analysis and design considerations are derived. The experimental results agree with the theoretical predictions and confirm the validity of the proposed design approach.
A backlight module driver driving high-power red, green, and blue light emitting diodes (RGB LEDs) for a 19-inch LCD is proposed. DC-to-DC series resonant converters (SRCs) with zero-voltage switching (ZVS) and constant-output-current control are implemented to drive the RGB LED arrays. Phase-shifted pulse width modulation (PSPWM) dimming signals are adopted to improve the output voltage regulations of the SRCs at light loads. In order to track the brightness and color temperature, the hysteresis control algorithm is performed by a digital signal processor (DSP). Analysis and design considerations of the proposed drivers are presented. Experimental results agree well with the theoretical predictions and confirm the validity of the proposed approach.

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