在現今的消費性電子市場，可攜式電子產品的蓬勃發展，使得直流—直流轉換器逐漸成為電源供應不可或缺的一環。然而切換式轉換器的高輸出雜訊限制了其應用範圍，跳頻展頻方式為改善輸出雜訊方法之一。但跳頻時產生的輸出電壓擾動，使得轉換器的效能表現下降。
本論文提出具三角波切換之電流模式降壓轉換器。此轉換器除了可以改善輸出雜訊，也減少跳頻時所產生的輸出電壓擾動。此轉換器使用TSMC 0.35µm 2P4M CMOS製程來設計，晶片面積為1.45×1.53mm2。操作頻率為1.5 MHz到5.5 MHz，與未變頻相比，最大輸出雜訊改善可達30 dB，而輸出電壓漣波為12 mV。與其他相關文獻的比較，輸出電壓漣波值有極大的改善值，也加大了轉換器的應用範圍。

In today’s consumer market, portable electronic devices are a great demand to make dc-dc converters becoming indispensable for power supply. However, the high output voltage noise of dc-dc converters restricts the applications. One methodology to reduce the output voltage noise is achieved with FHSS (Frequency Hopping Spread Spectrum) technique. The technique causes output voltage variation when the switching frequency varies, so the performance of the dc-dc converters will be degraded.
This thesis presents a current-mode buck converter with triangular-wave switching. The converter not only improves the output voltage noise, but also reduces the output voltage variation when the switching frequency hops. This converter was designed with TSMC 0.35μm 2P4M CMOS process, and the chip size is 1.45×1.53mm2. The operating frequency is from 1.5 MHz to 5.5 MHz and the interval between those frequencies is 0.5MHz.The maximum output noise reduction is about 30dB and the output voltage ripple is only 12 mV. Compared with previous works, the value of the output voltage ripple is significantly reduced to broaden the application range of the dc-dc converters.

參考文獻
[1] J.W. Xiao, A. Peterchev, and J. S. Sanders, “An Ultra-Low-Power Digitally-Controlled Buck Converter IC for Cellular Phone Applications,” in Proc. IEEE Applied Power Electronics Conference and Exposition, vol.1,pp. 383-391, 2004.

[2] 陳秋麟 “電源管理積體電路設計” National Taiwan University Course,2011.

[3] C.Y. Wang “A Current-Mode Buck Regulator with an Adjusted-Slope Compensation Ramp,” National Cheng Kung University MS. Thesis, 2005.

[4] R.W. Erickson, D. Maksimovic, Fundamentals of Power Electronics. Norwell, MA:Kluwer, 2001.

[5] J. Y. Guo, “Investigating Feedforward Mechanism in Current Mode Control,”in Proc. IEEE Applied Power Electronics Conference and Exposition , pp. 1008-1013,2006.

[6] 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 Circuit, Vol. 39, Issue 1, pp.3-14,Jan. 2004.

[7] Dr. Ray Ridly “Current Mode or Voltage Mode?, ”Switching Power Magazine, Oct.2000.

[8] N. Mohan, Tore M. Undeland, and William P. Robbins, “Power Electronics: Converters, Applications, and Design”, 3rd Edition, Wiley.

[9] C. Chang, “Robust Control of DC-DC Converters: The Buck Converter”, in Proc. IEEE Power Electronics Specialists Conference, Volume 2, pp.1094 – 1097, Jun 1995.

[10] P. Y. Kuo, D. Zhou, and Z. M. Lin “A Low-Dropout Regulator with Low ESR, Low Line Regulation and High Currency Efficiency Using Low Output-Resistance Voltage Buffer,” in Proc. Electron Devices and Solid-State Circuits, IEEE Conference, pp.473- 476,2007.

[11] T.Y. Yu “A High-Efficiency Synchronous CMOS Switching Regulator with PWM/PFM-Mode Operation, ” National Chiao Tung University MS. Thesis, 2003.

[12] J.N. Kitchen, C. Chu, S. Kiaei, and B. Bakkaloglu, “Combined Linear and Modulated Switch-Mode PA Supply Modulator for Polar Transmitters,” IEEE J. Solid-State Circuits, vol. 44, no. 2, pp. 404-413, Feb. 2009.

[13] C. Tao and A. A. Fayed, “Spurious-noise-free buck regulator for direct powering of analog/RF loads using PWM control with random frequency hopping and random phase chopping,” in Proc. IEEE ISSCC, pp. 396–397, Feb. 2011.

[14] N.Y HO, and P.K.T. Mok, “Ramp Signal Generation in Voltage Mode CCM Random Switching Frequency Buck Converter for Conductive EMI Reduction,” IEEE Custom Integrated Circuits Conference, pp.1-4, sept.2010.

[15] P.J Liu, J.N Tai, H.S Chen, J.H Chen, and Y.J. Chen, “Spur-Reduction Design of Frequency-Hopping DC–DC Converters,” IEEE Transactions on Power Electronics, Vol.27, No.11, pp. 4763-4771, Nov. 2012.

[16] S. K. Dunlap, and T. S. Fiez, “A noise-shaped switching power supply using a delta–sigma modulator,” IEEE TCAS-I, vol.51, no.6, pp. 1051–1061, Jun. 2004.

[17] J. N. Kitchen, I. Deligoz, S. Kiaei, and B. Bakkaloglu, “Polar SiGe class E and F amplifiers using switch-mode supply modulation,” IEEE Transactions on Microwave Theory and Techniques, vol. 55, no. 5, pp. 845–856, May 2007.

[18] C. Tao and A. A. Fayed, “A Buck Converter With Reduced Output Spurs Using Asynchronous Frequency Hopping” IEEE Transactions on Circuits and Systems II: Express Briefs, Vol.58 ,No.11,pp 709-713,2011.

[19] E.J. Kim, C.H. Cho, and W. Kim, “Spurious Noise Reduction by Modulating Switching Frequency in DC-to-DC Converter for RF Power Amplifier” IEEE RFIC Symposium, pp. 43-46, May, 2010.

[20] R. Jacob Baker, “CMOS Circuit Design, Layout, and simulation” Wiley, 2011.

[21] D. M. Monticelli, “A quad CMOS single-supply op amp with rail-to-Rail output swing,” IEEE J. Solid-State Circuits, vol. 21, pp. 1026–1034,Dec. 1986.

[22] A. J. Stratakos, S. R. Sanders, and R. W. Brodersen, “A low-voltage CMOS DC–DC converter for a portable battery-operated system,” in Proc. IEEE Power Electronics Specialists Conf., pp. 619–626,1994.

[23] P.T. Krein, Elements of Power Electronics. New York, NY: Oxford Univ. Press, 1998.

[24] C. Yoo, “A CMOS buffer without short-circuit power consumption,”
IEEE Trans. Circuits Syst. II, vol. 47, pp. 935–937, Sept. 2000.

[25] B. Razavi, Design of Analog CMOS Integrated Circuits. Boston, MA

[26] L. Christen , O. Yilmaz , S. Nuccio , X. Wu , and A. E. Willner,“Optical Pseudo-Random Bit Sequence Generator using a Dual-Drive Mach-Zehnder Modulator as a Linear Feedback Shift Register" In Proc. IEEE Lasers and Electro-Optics Society, pp.274-275,2008.

[27] M. Perlman, “The Decomposition of the States of a Linear Feedback Shift Register Into Cycles of Equal Length” IEEE Transactions on Circuits and system, vol.19, no.11,pp.1029-1035,1970.