展頻時脈產生器之設計與實作

Design and implementation of spread spectrum clock generator

楊子震(Tzu-Chen Yang)

指導教授 ： 陳少傑

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.10117

摘要

在現今的積體電路設計中，系統單晶片(SoC)是一個主流方向。鎖相迴路及相關的電路更是必須朝向SoC方面發展。隨著製程進步，電晶體的尺寸越來越小但對於被動元件的尺寸來說沒有變小。低通濾波器是鎖相迴路其中的一個區塊，是由電容以及電阻所組成。在過去的幾年中，為了降低晶片面積跟成本通常將低通濾波器設計在晶片外部。為了達到SoC的目的，希望將迴路濾波器整合進入晶片當中。然而，這些迴路濾波器在晶片當中佔了相當大的面積。由於在展頻時脈產生器中，通常會有一個較小的頻寬。所以在較小的頻寬下會造成較大的低通濾波器。如果我們欲降低此迴路濾波器的面積，可以利用一個除二電路來達到此目的。

關鍵字

展頻時脈 ； 鎖相迴路

並列摘要

Today System-on-Chip (SoC) is a mainstream for integrated-circuit design. PLLs are essential for SoC. The transistor size becomes much smaller when the CMOS process is improved, but not for on-chip passive components. A low-pass filter which is composed of capacitors and resistors is one of the building blocks in PLL. In the past years, a low-pass filter is always designed off-chip to reduce the chip size and production cost. Nowadays, a low-pass filter integrated into a chip is preferred for SoC. However, these passive components will occupy large area in a chip. We usually use a smaller bandwidth in a spread spectrum clock generator (SSCG), thus it will lead to a larger low-pass filter in the SSCG system. Since we want to reduce these passive components, a novel divided-by-two circuit is proposed and used in the PLL.

並列關鍵字

spread spectrum clock ； phase lock loop

參考文獻

[1] “Spread Spectrum Timing for Hard Disk Drive Applications,” http://www.cypress.com, Nov. 2000.

[5] H. H. Chang, I. H. Hua and S. I. Liu, "A spread spectrum clock generator with triangular modulation," IEEE J. Solid-State Circuits, vol. 38, pp. 673-676, Apr. 2003.

[6] F.M. Gardner, “Charge-Pump Phase-Lock Loops,” IEEE Trans. Communications, vol.28, no.11, pp.1849-1858, Nov. 1980.

[8] K. Hardin et al. “Spread Spectrum Clock Generation for the Reduction of Radiated Emissions,” Proceedings of the 1994 IEEE International Symposium on Electromagnetic Compatibility, pp. 227-231, Aug. 1994.

[9] F. Lin and D.Y. Chen, “Reduction of Power Supply EMI Emission by Switching Frequency Modulation,” The VPEC Tenth Annual Power Electronics Seminar, Virginia Power Electronics Center, Blacksburg, Virginia, pp. 20-22, Sept. 1992.