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《计算机技术与发展》[ISSN:1006-6977/CN:61-1281/TN]

卷:

26

期数:

2016年04期

页码:

144-147

栏目:

应用开发研究

出版日期:

2016-04-10

文章信息/Info

Title:

 A Spread Spectrum Clock Generator for SATA3 Based on Sigma Delta

文章编号:

1673-629X（2016)04-0144-04

作者:

 王希; 邵刚; 吕俊盛; 田泽

 西安航空计算技术研究所 集成电路与微系统设计航空科技重点实验室

Author(s):

 WANG Xi；SHAO Gang；Lü Jun-sheng；TIAN Ze

关键词:

 ; SATA3; 锁相环; 扩频时钟;  三角波调制

Keywords:

 ; SATA3; PLL; spread spectrum clock; triangular waveform modulation

分类号:

TP39

文献标志码:

A

摘要:

 文中设计了一款符合SATA3协议、具有Sigma Delta调制特性的扩频时钟发生器。该电路基于小数分频锁相环,由相位比较器、电荷泵、环路滤波器、压控振荡器、分频器、三角波发生器和扩频调制器组成。通过三角波发生器产生固定频率的三角波,经过Sigma Delta调制器对三角波进行处理,实现对锁相环环路分频比的调制,进而使电路的环路特性满足SATA3协议的要求。该扩频时钟发生器的输入时钟为100 MHz,时钟输出以31.25 kHz的调制频率由6 GHz向下扩频5000 ppm,得到的功率相比于未使用向下扩频时减小了21.58 dB。文中所设计的电路采用65 nm CMOS工艺,所用的电源电压为1.2 V,功耗大小约为43 mW。该结构受到工艺参数变化的影响较小,电路结构相对简单,性能稳定,便于集成。

Abstract:

 A spread spectrum clock generator for SATA3 with Sigma Delta modulation is proposed. The design is based on a fractional-N PLL,including phase detector,charge pump,loop filter,voltage-controlled oscillator,divider and triangular waveform modulator. The output waveform with constant frequency produced by the triangular waveform generator is transformed by a sigma delta modulator and controls the loop frequency divider to get compliance to SATA3. The circuit generates a 6 GHz clock with a 5000 ppm down spread spec-trum modulated by a triangular waveform at 31. 25 kHz with a 100 MHz reference clock. The power obtained is reduced 21. 58 dB com-pared with not using spread spectrum. The circuit adopts 65 nm CMOS with a supply of 1. 2 V,consuming 43 mW. The structure affected by process parameters change is small,and the circuit structure is relatively simple,with stable performance,easy to integration.

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更新日期/Last Update: 2016-06-17