82598EB Datasheet, PDF (563/596 Pages) Intel Corporation – Intel® 82598EB 10 Gigabit Ethernet Controller Datasheet

Intel^® 82598EB 10 GbE Controller - XAUI, KX/KX4, CX4 and BX Layout Recommendations
Microstrip Example:
• Layer 1 is a signal layer.
• Layer 2 is a ground layer.
• Layer 3 is used for power planes.
• Layer 4 is a signal layer. (Careful routing is necessary to prevent cross talk with layer 5.)
• Layer 5 is a signal layer. (Careful routing is necessary to prevent cross talk with layer 4.)
• Layer 6 is used for power planes.
• Layer 7 is a signal ground layer.
• Layer 8 is a signal layer.
Note: Layer 4 and 5 should be used mostly for low-speed signals because they are referenced to
potentially noisy power planes which might also be slotted.
Stripline Example:
• Layer 1 is a signal layer.
• Layer 2 is a ground layer.
• Layer 3 is a signal layer.
• Layer 4 is used for power planes
• Layer 5 is used for power planes
• Layer 6 is a signal layer.
• Layer 7 is a signal ground layer.
• Layer 8 is a signal layer.
Note:
To avoid the effect of the potentially noisy power planes on the high-speed signals, use offset
stripline topology. The dielectric distance between the power plane and signal layer should be
three times the distance between ground and signal layer.
This board stack up configuration can be adjusted to conform to your company's design rules.
8.3.2.2 Trace Geometries
Two types of traces are included: Microstrip or Stripline. Stripline is the preferred solution. Stripline
transmission line environments offer advantages that improve performance. Microstrip trace
geometries can be used successfully, but it is our recommendation that Stripline geometries be
followed.
The following table highlights the height pair-to-pair spacing differences that are recommended
between Stripline and Microstrip geometries.
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