本論文主要研製一台數位控制之LLC諧振轉換器，在DC/DC的電源轉換器上，LLC諧振轉換器是透過開關的寄生電容與諧振槽達零電壓切換的優勢，降低開關的切換損失同時減少寄生元件所引起的不良效應，當輸入電壓下降時亦可透過變頻的方式提高電壓增益，維持輸出端的穩定。電路分析使用一階諧波近似方法，搭配MATLAB模擬出電壓增益對頻率響應圖，從中了解品質因數Q_e與電感比值K對電路的影響。透過數位回授控制系統取代傳統類比IC，可以節省許多的類比的輔助電路，因為在傳統回授設計上傳統類比IC設計較為困難且複雜，尤其在頻率、控制方法都會受到參數設計上的限制，而數位控制具有響應快、靈活性強、環境敏感度低、受溫度、零件老化影響較小等優勢，本論文最後實作出一台144W之DC/DC電源供應器，其輸入電壓為380 ~ 400V，輸出直流電壓24V，滿載輸出電流6A，其軟硬整合以實驗結果驗證理論分析，並研擬未來研究方向。;This paper mainly develops a digitally controlled LLC resonant converter. On the DC/DC power converter, with parasitic capacitance and resonant tank, the LLC resonant converter has the advantage of zero voltage switching, reducing the switching loss of the switch and adverse effects caused by parasitic components. When the input voltage drops, the voltage gain can also be increased by means of frequency conversion to maintain the stability of the output. The circuit analysis uses the first-order harmonic approximation method. With MATLAB, the voltage gain vs. frequency response graph is simulated, and the influences of the quality factor Q_e and inductance ratio K to the circuit are known. Replacing traditional analog ICs with digital feedback control systems can save many auxiliary circuits, because traditional analog IC design is difficult and complicated in traditional feedback design, especially in frequency and control methods. Digital control has the advantages of fast response, high flexibility, low environmental sensitivity, and low temperature and component aging. At the end, this paper design a 144W DC/DC power supply with an input voltage of 380 ~ 400V and output DC voltage of 24V with the full-load output current 6A. The soft and hard integration is verified by experimental results. Finally the future possible research is mentioned.