JAJSBK7H January 2012 – February 2018 DS125DF410
To minimize the effects of crosstalk, a 5:1 ratio or greater should be maintained between inter-pair spacing.
Figure 12 depicts different transmission line topologies which can be used in various combinations to achieve the optimal system performance. Impedance discontinuities at the differential via can be minimized or eliminated by increasing the swell around each hole and providing for a low inductance return current path. When the via structure is associated with thick backplane PCB, further optimization such as back drilling is often used to reduce the detrimental high frequency effects of stubs on the signal path.