有限地平面上差分对共模噪声的分析  

Analysis of Differential Pair CM Noise on Finite Ground Planes

作　　者：唐世悦[1] 高新成[2] 

机构地区：[1]安徽大学物理与材料科学学院,合肥230039 [2]中国电子科技集团公司第三十八研究所,合肥230031

出　　处：《电讯技术》2008年第9期33-37,共5页Telecommunication Engineering

基　　金：国家自然科学基金资助项目(10505020)

摘　　要：共模噪声是高速数字电路产生电磁干扰的主要原因,而共模电感又是共模噪声大小的决定因素。以多层板的微带线为模型,推导出在偏离地平面中心以及跨越不连续地平面的情况下,PCB上差分对共模电感的定量表达式,并对其共模噪声的特性进行了详细讨论。其结论可以帮助设计人员理解共模噪声产生机制,并针对具体电路走线定量分析,提前准确发现设计中潜在的问题。Electromagnetic interference （EMI） in high- speed digital circuit is mainly generated by Common -mode（CM） noise, and the CM inductance is responsible for CM noise magnitude. The expression of differential pair CM inductance on PCB is deduced under the condition of departuring ground plane center and spanning discontinuously ground plane based on the model of microstrip. Then the characteristics of CM noise of differential pair are discussed in detail. The conclusion can help designers to understand the generation mechanism of the CM noise, and to quantificationally analyze the detailed circuit distribution to find the potential problems previously in design scheme.

关 键 词：PCB设计 电磁干扰 差分对 共模噪声 共模电感 

分 类 号：TN911.4[电子电信—通信与信息系统] TP274[电子电信—信息与通信工程]