具有可適性模式轉換機制之高效率電流式直流對直流轉換器

A New Current-mode DC-DC Converter with Adaptive Mode-hopping Mechanisms

張嘉顯(Chia-Hsien Chang)

指導教授 ： 吳紹懋

元智大學/電機通訊學院/電機工程學系/碩士(2007年)

摘要

本篇論文提出一個具有可適性模式轉換機制之高效率電流式直流對直流轉換器。利用電流感測器的技術，依據負載電流大小而操作在連續導通模式與不連續導通模式間切換之可適性模式轉換機制，使其在不同應用之下皆可達到很高的轉換效率。而為了增加彈性，此模式轉換的基準電流可依據不同的應用以數位方式調整。本篇論文亦提出功率消耗及轉換效率之分析與討論。根據模擬的結果，此直流對直流轉換器的效率高達94%，且最大輸出漣波電壓在20毫伏以下，而輸出電流範圍在50mA到350mA之間。在輸入電壓範圍在2.4V到4.2V之間，直流對直流轉換器之操作頻率為0.3到1.7百萬兆赫。此直流對直流轉換器以TSMC 0.35-um 2P4M CMOS製程實現，晶片大小為2.07mm2。除了外接之電感、電容及回授之電阻，包含功率電晶體及所有的元件都在晶片之中。

關鍵字

直流對直流 ； 轉換器 ； 可適性

並列摘要

In this thesis, presented is a high-efficient current-mode DC-DC converter with adaptive mode-hopping mechanism. By employing a current sensing technique, the mode-hopping mechanism enables the mode switching between CCM and DCM according to the load current so as to maintain a high conversion efficiency regardless of the operational status of the applications. Moreover, the level of the load current for mode switching is programmable depending on the applications. Power loss and conversion efficiency analyses are also studied and presented. According to the simulation results, the efficiency of the DC-DC converter can be up to 94% while the maximum peak-to peak output voltage ripple is less than 20mV and the output current ranges between 50mA and 350mA. The DC-DC converter operates at a switching frequency from 0.3 to 1.7MHz from a supply voltage ranging from 2.4 to 4.2V. The DC-DC converter was implemented in TSMC 0.35-μm 2P4M CMOS process with die size of 2.07 mm2. Except the external inductor, capacitor and feedback resistors, all the devices including the power switches are on chip.

並列關鍵字

DC-DC convertr ； adaptive mode-hopping ； current mode

參考文獻

[3] AN1845: Choosing the right DC-DC converter for automotive applications, Maxim Integrated Products, Dec 2002.

[6] J. Stratakos, High-Efficiency Low-Voltage DC-DC Conversion for Portable Applications, Ph.D. Dissertation, University of California, Berkeley, 1998.

[7] Forghani-zadeh, H.P.; Rincon-Mora, G.A., "Current-sensing techniques for DC-DC converters," Circuits and Systems, 2002. MWSCAS-2002. The 2002 45th Midwest Symposium, pp. 4-7 Aug. 2002.

[9] P. E. Allen and D. R. Holberg, CMOS analog circuit design, Second Edition, OXFORD, 2002.

[10] B. Razavi, Design of Analog CMOS Integrated Circuits, McGRAW-HILL.