Analysis And Research For The SSN Of PCB Level In The High Speed Circuits

The degradation of the signal integrity (SI) due to the simultaneous switching noise(SSN) has become a choke point to the design and manufacture of the high-speed digitalcircuit with the increasing requirements of high clock frequency. Therefore this paperfocuses on the elimination and suppression of the interference to the power distributionnetwork due to the SSN in the high speed circuits. Based on the study of the basictheory of the signal integrity, the generation mechanism of the SSN is analyzed bytheoretical analysis and simulation in this paper. Aiming at the shortcomings of the mainsuppression methods, the Electromagnetic Bandgap (EBG) structure that is introducedfor the suppression of the SSN in recent years is analyzed. In this article, an novelstructure of U-bridged Electromagnetic Bandgap structure power plane is proposedthrough the research on the method of lower the center frequency and broaden thebandwidth. The simulation results show that the bandwidth of this new structure is4.32GHz and the lower side cutoff frequency is380MHz. The elimination ofsimultaneous switching noise for this kind of U-bridged coplanar EBG structure is moreeffective below600MHz. Moreover, the eye diagram of the structure is analyzed. Thedegradation of the maximum eye open and the maximum eye width on the structure isabout1.2%and5.7%respectively, so that the SI of this new structure is acceptable.