高速数字电路设计中电源噪声抑制的研究

发布时间：2018-02-07 16:38

本文关键词： 信号完整性电磁带隙结构电源分配网络同时开关噪声　出处：《西安电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着大数据时代的来临和云计算的兴起,“处理速度要求快,时效性要求高”是大数据区分于传统数据最显著的特征。高速的传输和大量数据的处理要求,给电路板(PCB)的设计带来了很多问题。首先由于时钟边沿速率变快,信号的高频分量频率越来越高,除了会影响信号的传输质量,产生反射、串扰噪声,还会对电源分配网络的稳定供电造成很大影响。在高速电路和混合信号电路的设计中,减小电源分配网络噪声是电源完整性设计的一个主要研究方向。为了减小封装或印刷电路板(PCB)上的电源噪声,常用的解决方法主要基于去耦或隔离的思想。本文介绍了电源分配网络(PDN)的组成结构,并通过分析一些常见电源噪声产生的原理,使用去耦和隔离的思想介绍了一些减小电源噪声的方法。去耦的主要目的是使电源分配网络(PDN)在宽的频率范围内保持较小的阻抗值。而隔离设计则是通过使部分PDN为高阻抗,从而减少电源噪声的传播。本文研究的主要是电源分配网络中电源噪声的抑制问题,重点介绍了同时开关噪声(SSN)的产生原理和抑制方法。首先,介绍了高速电路发展历程以及现在面临的主要问题;接着,介绍PDN各组成部分及高频电路设计中各种噪声的影响,讨论去除电源噪声的方法及对应的原理,分析这些方法的优缺点。然后分析了同时开关噪声(SSN)的产生原理,为了降低SSN噪声对电源分配网络(PDN)的影响,提出了一些抑制同时开关噪声(SSN)的方法。比较传统的方法有加入去耦电容,分割电源平面等。然而这些传统的方法抑制带宽太窄、成本太高而不能被广泛采用。针对现有方法的缺点和不足,本文介绍了电磁带隙结构(EBG)抑制SSN噪声的方法,使用电磁带隙结构(EBG)可以很好的解决以上问题。此外还提出新型的内嵌式电磁带隙结构,该结构在电源层采用传统L-Bridge电磁带隙结构,在L-Bridge的结构中又内嵌了一个反向的L-Bridge结构,地平面保持完整。加入反向的L-Bridge结构后,相较于传统EBG结构,在内嵌式L-Bridge内部在-30dB的抑制深度下,抑制带宽有很大程度提升,抑制带宽为0.38-10 GHz。根据该结构的结构特征,给出低频工作时的集总等效电路模型,得到了谐振点的计算公式,使用谐振腔模型估算新结构的上截止频率。最后,分析该新型结构在内嵌式结构内部和外部走线的信号传输特性,通过仿真验证该EBG结构对信号完整性的影响。得出结论,相较于传统L-Bridge结构,嵌入反向ML-Bridge后显著提高了内部结构的阻带宽度和抑制深度,同时保证了内嵌结构外部区域布线的信号完整性。根据理论估算公式,通过调节内嵌结构的大小及各结构参数可以优化阻带特性。
[Abstract]:With the advent of big data era and the rise of cloud computing, "fast processing speed, high timeliness requirements" is the most significant feature that big data distinguishes from traditional data. It brings many problems to the design of PCB. Firstly, because the rate of clock edge becomes faster and faster, the frequency of high frequency component of the signal becomes higher and higher. Besides, it will affect the transmission quality of the signal, produce reflection and crosstalk noise. In the design of high speed circuit and mixed signal circuit, Reducing power distribution network noise is one of the main research directions in power integrity design. The common solutions are mainly based on decoupling or isolation. This paper introduces the structure of PDN, and analyzes the principle of noise generation. This paper introduces some methods to reduce power noise by decoupling and isolating. The main purpose of decoupling is to keep the impedance of power distribution network in a wide frequency range. In order to reduce the propagation of power noise, this paper mainly studies the suppression of power noise in power distribution network, especially introduces the generation principle and suppression method of simultaneous switching noise (SSN). This paper introduces the development of high speed circuit and the main problems it faces now, then introduces the influence of various noises in the design of PDN components and high frequency circuits, and discusses the methods of removing the noise from power supply and the corresponding principle. The advantages and disadvantages of these methods are analyzed. Then, the principle of simultaneous switching noise (SSN) generation is analyzed. In order to reduce the influence of SSN noise on power distribution network (PDN), Some methods of suppressing simultaneous switching noise (SSN) are proposed. The traditional methods include adding decoupling capacitance, dividing the power plane, etc. However, these traditional methods are too narrow in bandwidth. The cost is too high to be widely used. In view of the shortcomings and shortcomings of the existing methods, this paper introduces the method of SSN noise suppression by electromagnetic bandgap structure. In addition, a new embedded electromagnetic band gap structure is proposed, which adopts the traditional L-Bridge electromagnetic band gap structure in the power supply layer, and embedded a reverse L-Bridge structure in the L-Bridge structure. The ground plane remains intact. Compared with the traditional EBG structure, the embedded L-Bridge has a significant increase in the suppression bandwidth of 0.38-10 GHz compared with the traditional L-Bridge structure at a depth of -30 dB. The lumped equivalent circuit model for low frequency operation is given, and the formula for calculating the resonance point is obtained. The upper cutoff frequency of the new structure is estimated by using the resonant cavity model. The signal transmission characteristics of the inner and outer lines of the new structure are analyzed. The influence of the EBG structure on the signal integrity is verified by simulation. The conclusion is drawn that compared with the traditional L-Bridge structure, After embedding the reverse ML-Bridge, the stopband width and suppression depth of the inner structure are improved significantly, and the signal integrity of the external region of the embedded structure is ensured. The stopband characteristics can be optimized by adjusting the size of the embedded structure and the structural parameters.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN41

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