User manual

Advantech SOM-Express Design Guide
68 Chapter 5 Carrier Board Design Guidelines
Figure 5-32 10/100M Ethernet Interconnection
Figure 5-33 Gigabit Ethernet Interconnection
5.7.3.3 Critical Dimensions
There are two critical dimensions that must be considered during the layout phase of
an Ethernet controller. These dimensions are identified in Figure 5-34 as A and B.
Distance A: Transformer to RJ-45 (Priority 1). The distance labeled A should be
given the highest priority in the backplane layout. The distance between the
transformer module and the RJ-45 connector should be kept to less than 1 inch of
separation. The following trace characteristics are important and should be observed: