本論文實現一具有交替式相位遮蔽之多相降壓直流轉直流電源轉換器控制器，本控制器採用電流模式控制使各相轉換器達到均流、適應性輸出電壓準位與相位遮蔽。當輕載時，藉由相位遮蔽控制來啟用部分相轉換器而提升轉換器效率，但相位遮蔽控制使啟用之相轉換器的溫度高於其他相轉換器而造成溫度分布不平均。為了解決這個問題，本文實現了交替式相位遮蔽控制，在輕載時，各相轉換器輪流供給輸出電流使各相轉換器均流，讓功率分散在各相轉換器而提升可靠度，且無論啟用相轉換器數多寡，本控制器皆採用交錯式控制。此外，藉由高降壓比之應用，本文提出一控制架構，利用輸入電流來控制各相轉換器，減少了元件數量與控制器腳位。最後，本控制器採用TSMC 0.25um CMOS高壓製程實現此控制晶片，並以輸入電壓12 V，輸出電壓1.2 V，輸出功率72 W之三相降壓轉換器來驗證此控制晶片之可行性。

In this thesis, a controller for a multiphase DC-DC buck converter with alternate phase-shedding is realized. The current mode control is adopted in this controller for achieving current sharing, adaptive voltage position, and phase-shedding function. With phase-shedding control, the efficiency at low load condition is improved by turning-on appropriate number of phase(s), but the temperature on the active phase(s) is higher than the off phase(s) that cause the temperature unevenly distribution. To solve this problem, the alternate phase-shedding is implemented in the proposed controller. The phases take turns to provide the load current at low load condition to distribute power to each phase and share the same load as well as improve reliability. The proposed controller would implement interleaved control regardless the number of active phases. In addition, taking advantage of the application of high step-down ratio, the proposed control structure that input current is sensed to control each phase is adopted. The number of components and pins of controller can be reduced. This chip is fabricated with TSMC 0.25um CMOS high voltage mixed signal general purpose process and is tested with an input voltage of 12 V, output voltage of 1.2 V, and output power of 72 W three-phase buck converter to verify the feasibility.

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