本論文主要為探討同步整流式LLC 半橋串聯諧振轉換器的設計。一
般而言，LLC 可分為兩種操作模式，最低切換頻率介於兩諧振頻率之間
（wr2<ws,min< r1），以及最低切換頻率大於第一諧振頻率（wr1< ws,min）。
對於同步整流來說，LLC 轉換器必須操作在切換頻率大於諧振頻率的地
方。本論文中也提出了一個電壓箝位驅動電路，用來同時驅動一次側的
功率開關以及二次側的整流開關。如此一來此轉換器就不需要上/下臂驅
動電路。轉換器的動態分析是以IsSpice 來模擬。本論文設計、模擬並實
際做出一台250W 之同步整流式LLC 半橋串聯諧振轉換器，其滿載下效
率在94%，來驗證實際之電路特性，其特性符合我們所設計。

This thesis focuses on the design of a half-bridge LLC series resonant
converter (SRC) with synchronous rectification (SR). Generally, the operation
of SR-LLC-SRC can be in the ranges of wr2< ws,min< wr1 and wr1< ws,min. For
SR-LLC-SRC, only the operation of ws,min> wr1 is valid. In this thesis, a
synchronous rectification strategy for LLC-SRC is proposed with a
voltage-clamped drive circuit, which is designed to simultaneously drive
primary-side switches and secondary-side rectifiers. In this thesis, no
high/low-side driver circuit is required for the driver of pair power switches.
The dynamic performance of the proposed SR-LLC-SRC is simulated by
IsSpice and the design considerations are examined thoroughly. A design of
250W SR-LLC-SRC is examined and compared with the conventional
LLC-SRC, and a high efficiency up to 94% at full load is achieved. All
performances verified by simulation and experiment are quite well close the
theoretical predictions.

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