本論文採用脈波省略控制技術，實現一緩啟動電路，此電路用來防止直流-直流轉換器在啟動過程中的浪湧電流和輸出過充電壓。在啟動過程時，誤差放大器的參考電壓將呈現階梯式的遞增。此緩啟動電路可整合於晶片之中，所以無須外接元件，以減少PCB面積與成本，
本篇論文以台積電0.35-μm 2P4M 3.3/5 V CMOS製程實現。規格如下：輸入電壓為5 V，輸出電壓為3.3 V，工作頻率為1 MHz且輸出最大負載電流為500 mA。根據模擬結果，使用本論文所提出的緩啟動電路，直流-直流轉換器的最大輸出電壓過充值為70 mV。

This thesis presents a novel soft-start circuit that adopts a pulse skipping control to prevent inrush current and output voltage overshoot during the start-up period of the dc-dc converters. The voltage reference of the error amplifier is increased as a stair-case signal during the start-up period. The proposed soft-start circuit is fully integrated into a chip without external components, so it leads to a reduction in PCB area and cost.
The chip is implemented with TSMC 0.35-μm 2P4M CMOS process. The specifications of the dc-dc converter are: the input voltage is 5 V, output voltage is 3.3 V, the operating frequency is 1 MHz, and the maximum output current is 500 mA. According to the simulation results, the maximum output voltage overshoot of the dc-dc converter with the proposed soft-start circuit is 70 mV.

[1] M. AI-Shyoukh and H. Lee, “A Compact Ramp-Based Soft-Start Circuit for Voltage Regulators,” IEEE Trans. Circuit and Systems, vol. 56, no. 7, pp. 535–539, July 2009.
[2] W. AI-Shyoukh, H. Lee, and R. Liu, “A Compact Fully-Integrated Extremum-Selector-Based Soft-Start Circuit for Voltage Regulators in Bulk CMOS Technologies,” IEEE Trans. Circuit and Systems, vol. 57, no. 10, pp. 818–822, Oct. 2010.
[3] 梁適安，交換式電源供應器之理論與實務設計，二版，全華科技圖書，第1-104頁，2008。
[4] D. S. Kim, J. Kim, J. Kim, and C. Kim “An On-chip Soft-Start Technique of Current-mode DC-DC Converter for Biomedical Applications,” IEEE Asia Pacific Conf. Circuit and Systems, pp. 500–503, Dec 2010.
[5] K. H. Chen, C. J. Chang, and T. H. Liu, “Bidirectional Current-Mode Capacitor Multipliers for On-Chip Compensation,” IEEE Trans. Power Electronic, vol. 23, no. 1, pp. 180–188, Jan 2008
[6] Y. Bing, L. Xinquan, Y. Qiang, and J. Xinzang, “A Novel compact Soft-Start circuit with internal circuitry for DC-DC converters,” IEEE Int. Conf. ASIC. pp. 450–453, Oct. 2007.
[7] W. R. Liou, P. H. Chen, M. L. Yeh, and C. T. Kuo, “A Dual-Mode Step-Up DC/DC Converter IC with Current-Limiting and EMI Reduction techniques,” ICCCAS. Communication, Circuits and Systems, pp. 1332–1336, May. 2008.
[8] F. F. Ma, W. Z. Chen, and J. C. Wu, “A Monolithic Current-Mode Buck Converter with Advanced Control and Protection Circuits,” IEEE Trans. Power Electronic, vol. 22, no. 5, pp. 1836–1846, Sept 2007.
[9] L. Huang, J. Wang, X. Fu, and F. Run “A Soft-Start circuit for automobile voltage regulator,” ICECC Trans. Electronics, Communications and Control, pp. 673–676, Sept 2011.
[10] W. Yan, W. Li, and R. Liu, “A Noise-Shaped Buck DC-DC Converter With Improved Light-Load Efficiency and Fast Transient Response,” IEEE Trans. Power Electronic, vol. 26, no. 12, pp. 3908–3924, Dec. 2011.
[11] Y. Wu, Y. S. Tsui, and K. T. Mok, “Area-and Power-Efficient Monolithic Buck Converters with Pseudo-Type III Compensation,” IEEE J. Solid-State Circuits, vol. 45, no. 8, pp. 1446–1455, Aug. 2010.
[12] P. E. Allen and D. R. Hoolberg, “CMOS Analog Circuit Design,”, New York: Oxford. 2002.
[13] C. F. Lee, and 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
[14] Behzad Razavi, “Design of Analog CMOS Integrated Circuit,” Boston, MA:McGraw-Hill, 2001.
[15] C. Y. Leung and P. K. T. Mok, “An Integrated CMOS Current-Sensing Circuit for Low-Voltage Current-Mode Buck Regulator,” IEEE Trans. Circuits and Systems. vol. 52, no. 7, July 2005.
[16] A. I. Pressman, “Switching Power supply design,” Second Edition, McGraw-Hill, 1998.
[17] R. W. Erickson and D. Maksimovic, “Fundamentals of Power Electronics,” Norwell, MA: Kluwer Academic, 2001.
[18] Poki Chen, “Analog IC Layout,” Electronic Department, National Taiwan University of Science and Technology, Summer 2007.