可攜式電子產品短小輕薄功能完整是產品趨勢也是主要的需求，因此低功率高效率成為可攜式電子產品的首要考量，這些利用電池為電力來源的電子電路需要一個能夠提供穩定電壓的電源轉換電路，此電源轉換電路必須要是低功率消耗與高轉換效能，以延長電池工作時間，為提升轉換效能本論文題出一個電流模式控制之降壓式電源轉換器。
本論文所提出的電流模式控制降壓式電源轉換器，其原理主要是利用偵測電感上電流變化以加速因負載改變時之暫態反應時間，再將一般電流模式控制中所需要用到的電壓轉電流電路去除並且利用電路設計技巧降低內部各個子電路的操作電流消耗，進而提升整體的轉換效能。相較於一般電流模式控制穩壓，此穩壓器會有較高的轉換效能， 此電流模式控制降壓切換式穩壓器的電路設計是以台灣積體電路製造股份有限公司0.35 um 3.3 V 互補式金氧半製程來實現， 而工作電壓的範圍為3.8 V~5.5 V ， 操作頻率為1.5 MHz，負載電流範圍為0.05 A~1 A，及轉換效能為97.4 %。此降壓式電源轉換器之線性調節度與負載調節度分別為17.5 mV/V 與1.15 mV/A，晶片面積為2.46 mm2。

In this changing rapidly era of electronic technology, the major demands of portable electronics are short, thin, and full functionalities. These sub-circuits of the portable electronics, which use batteries for power sources, need a stable supply voltage generating by power converters. These power converters must have low power consumption and high efficiency to extend the service time of portable electronics. Thus, a high efficiency current mode buck converter is presented in this thesis.
The proposed buck converter uses current-mode controlling mechanism to accelerate the transient response during the transient period. It senses the current variation of the output inductor. Therefore, it achieves low operating current and high efficiency by removing the V-to-I converting circuit. This buck converter has better performance in the specification of efficiency comparing with traditional buck converter with current-mode controlling. This current-mode buck converter is fabricated with TSMC 0.35um 3.3 V CMOS process. In the proposed buck converter, the operation voltage is form 3.8 V to 5.5 V, the output voltage is 3.3 V, the output current is from 0.05 A to 1 A, and the highest efficiency is 97.4 %. The line regulation and load regulation are 17.5 mV/V and 1.15 mV/A, respectively. The chip area is 2.46 mm2.

[1] W. L. Hsieh, “High switching dc-dc buck converters in current domain control,” NCTU MS. Thesis, 2008.
[2] D. Maksimovic, “Power management model and implementation of power management ICs for next generation wireless applications,” Tutorial presented at the International Symposium on Circuits and Systems, 2002.
[3] G. A. Rincon-Mora and P. E. Allen, “A low-voltage, low quiescent current, Low drop-out regulator,” IEEE J. Solid-State Circuits, vol. 33, no. 1, pp. 36–44, Jan. 1998.
[4] P. Favrat, P. Deval and M. J. Declercq, “A high-efficiency CMOS voltage doubler,” IEEE J. Solid-State Circuits, vol. 33, pp. 410-416, Mar. 1998.
[5] R. W. Erickson and D. Maksimovic, “Fundamentals of Power Electronics,” Norwell, MA: Kluwer, 2001.
[6] H. H. Ko, “A high efficiency synchronous CMOS switching buck regulator with accurate current sensing technique,” NCU MS. Thesis, 2007.
[7] P. K. T. Mok, “Converter design for integrated power management system,” Tutorial presented at the International Symposium on VLSI Design, Automation and Test, Apr. 2010.
[8] W. R. Liou, T. H. Chen, Y. L. Kuo, T. Y. Huang and M. L. Yen, “A high efficiency dual-mode buck converter IC for portable applications,” IEEE Trans. Power Electron., vol. 23, no. 2, pp. 667–677, Mar. 2008.
[9] H.-H. Huang, C. L. Chen and K. H. Chen, “Adaptive window control (AWC) technique for hysteresis dc–dc buck converters with improved light and heavy load performance,” IEEE Trans. Power Electron., vol. 24, no. 6, pp. 1607-1617, Jun. 2009.
[10] C. F. Lee and P. K. T. Mok, “A monolithic current-mode CMOS DC-DC converter with on-chip current-sensing technique,” IEEE J. Solid-State Circuits, vol. 39, no. 1, pp. 3-14, Jan. 2004.
[11] K. H. Cheng, C. W. Su and H. H. Ko, “A high-accuracy and high-efficiency on-chip current sensing for current-mode control CMOS dc-dc buck converter,” IEEE Conference on Electronics, Circuits and Systems, Aug. 2008, pp. 458-461.
[12] H. P. Forghani-zadeh and G. A. Rincon-Mora, “Current-sensing techniques for dc–dc converters,” in Proc. Midwest Symposium on Circuits and Systems, Aug. 2002, vol. 2, pp. 4–7.
[13] C. Y. Leung, P. K. T. Mok, K. N. Leung and M. Chan, “An integrated CMOS current-sensing circuit for low-voltage current-mode buck regulator,” IEEE Trans. Circuits Syst. II, vol. 52, no. 7, pp. 394–397, Jul. 2005.
[14] Z. Zhang, “Buck converter control cookbook,” Alpha & Omega Semiconductor Inc., Application notes, Aug. 2008.
[15] R. B. Ridley, “A new small-signal model for current-mode control,” Ph.D. dissertation, Virginia Polytechnic Institute and State University, Blacksburg, Nov. 1990.
[16] B. Razavi, “Design of analog CMOS integrated circuits,” New York: McGraw-Hill, 2001.
[17] W. M. C. Sansen, “Analog design essentials,” Springer, 2006.
[18] Y. H. Lee, S. J. Wang and K. H. Chen, “Quadratic differential and integration technique in V2 control buck converter with small ESR capacitor,” IEEE Trans. Power Electron., vol. 25, no. 4, pp. 829-838, Apr. 2010.
[19] C. Shi, B. C. Walker, E. Zeisel, B. Hu and G. H. McAllister, “A Highly Integrated Power Management IC for Advanced Mobile Applications,” IEEE J. Solid-State Circuits, vol. 42, no. 8, pp. 1723-1731, Aug. 2007.
[20] M. K. Kazimierczuk, “Pulse-width modulated DC–DC power converters,” John Wiley & Sons Ltd, 2008.
[21] C. L. Chen, W. J. Lai, T. H. Liu and K. H. Chen, “Zero current detection technique for fast transient response in buck dc-dc converters,” IEEE Symposium on Circuits and Systems, May 2008, pp. 2214-2217.
[22] H. P. Forghani-zadeh and G. A. Rincón-Mora, “An accurate, continuous, and lossless self-learning CMOS current-sensing scheme for inductor-based dc-dc converters,” IEEE J. Solid-State Circuits, vol. 42, no. 3, pp. 665-679, Mar. 2007.
[23] N. Mohan, T. M. Undeland and W. P. Robbins, “Power Electronics: Converter, Applications, and Design,” Second Ed., New York: Wiley & Sons, 1995.
[24] R. B. Ridley, “A new, continuous-time model for current-mode control,” IEEE Trans. on Power Electron., vol. 6, no. 2, pp. 271–280, Apr. 1991.
[25] Y. H. Lee, S. J. Wang, C. Y. Hsieh and K. H. Chen, “Current mode dc-dc buck converters with optimal fast-transient control,” IEEE Symposium on Circuits and Systems, May 2008, pp. 3045-3048.
[26] C. H. Lin, H. W. Huang and K. H. Chen, “Fast transient technique (FTT) in buck current-mode dc-dc converters for low-voltage SoC systems,” IEEE Custom Integrated Circuits Conference, Sept. 2008, pp.25-28.
[27] W. J. Lai, “High efficiency slope compensator with input independent load current identification in current mode dc-dc buck converters,” NCTU MS. Thesis, 2008.