高效率、高功率密度和體積小是現今電源轉換器發展的趨勢。本論文利用GaN E- HEMT研製具有寬輸入電壓範圍之錯相式返馳式DC-DC轉換器，使轉換器工作於1 MHz以提高轉換器的功率密度，此錯相式返馳式轉換器具漏感能量回收功能，且降低輸出電流漣波，提升轉換器的效率。本論文首先介紹錯相式返馳式轉換器之動作原理，分析穩態的重要特性，並探討GaN的特性及驅動電路設計。最後，實作一系統規格為輸入電壓範圍72~240 V、輸出電壓為24 V、額定功率為144 W，切換頻率操作於1 MHz之錯相式返馳式轉換器，再使用同步整流以降低導通損失提高效率，以驗證理論分析之可行性。實驗結果顯示此轉換器在輸入電壓72 V的最高效率在50％負載時為84.1％。

High efficiency, high power density, and small size has become the development trend of power converters. In this thesis, an interleaved flyback DC-DC converter with wide input voltage range with the GaN high electron mobility transistor (HEMT) is implemented for achieving high power density. The interleaved flyback converter inherent with leakage energy recycle function can reduce the output current ripple to improve efficiency which is suitable for 1 MHz operation. In this thesis, the operating principle and the steady-state characteristics of the interleaved flyback converter are analyzed. Also, the gate driver circuits design of GaN are discussed. Finally, an interleaved flyback converter with 1 MHz switching frequency laboratory prototype is implemented with input voltage range 72 V to 240 V, output voltage of 24 V, rated power of 144 W. In addition, the synchronous rectifiers are used at secondary side to reduce conduction loss for achieving higher efficiency to verify the theoretical analysis. The experimental results show that the highest efficiency is 84.1% at 50%load with the input voltage of 72 V.

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