本文旨在研究多相式降壓轉換器(Multi-phase Buck Converter)。多相式降壓轉換器具有高功率密度、高輸出電流、高精準度輸出電壓及快速系統暫態響應之特性，以因應新一代處理器。
本研究實際製作一部具12V輸入電壓、1V輸出電壓及最高輸出電流120A之八相式降壓轉換器，並利用IsSpice軟體模擬八相式降壓轉換器電路，以驗證其可行性。實作電路分為控制功率開關訊號電路與功率級兩部份，控制PWM訊號電路採用立錡科技公司所生產的四相式控制IC RT9245A與相移電路，相移電路由CD4011 Buffer IC串聯組成，功率級則利用八組降壓轉換器電路架構並聯。

The thesis presents a multiphase buck converter design. Multi-phase buck converters have the characteristics of high power density, high currents, accurate voltage output, and fast transient-response. Therefore, it is suitable to supply power to a new generation of central processing units.
A 1V eight-phase buck converter is implemented with a 12V input and a 120A load. It was simulated utilizing IsSpice to check its feasibility.
The eight-phase buck converter consists of a circuit of PWM signal control power switch and a power stage. Circuit of PWM signal control switch combines the Richtek- RT9245A as a four-phase control IC and a phase shift circuit with CD4011 in series. The power stage consists of eight buck converters.

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