Critical Dimensions For An Integrated Magnetics Module; Distance A: The Overall Length Of Differential Traces; Distance B: Ethernet Controller To Chipset; Distance C: Lan Controller To Pcb Edge - Intel 82541PI Design Manual

4.3

Critical Dimensions for an Integrated Magnetics Module

Figure 6 shows the critical dimensions for component placement with an integrated magnetics
module.
C h ip se t
Figure 6. Critical Dimensions for 82562GZ(GX) and 82541PI(ER) Component Placement with
Integrated Magnetics Module
4.3.1

Distance A: The Overall Length of Differential Traces

The overall length of differential pairs should be between one and four inches measured from the
Ethernet controller to the RJ-45 connector having integrated magnetics (shortest lengths give the
best performance.).
4.3.2

Distance B: Ethernet Controller to Chipset

For LCI on 82562GZ(GX) devices, the maximum length should be less than 10 inches on an ICH5,
ICH6, or ICH7 platform. For the PCI bus on 82541PI(ER) controllers, the bus routing should meet
PCI specifications.
4.3.3

Distance C: LAN Controller to PCB Edge

The Ethernet controller should be placed at least one inch from the PCB edge (two inches is
preferred.).
4.4

Differential Pair Trace Routing

Trace routing considerations are important to minimize the effects of crosstalk and propagation
delays on sections of the PCB where high-speed signals exist. Signal traces should be kept as short
as possible to decrease interference from other signals, including those propagated through power
and ground planes.
Application Note (AP-468)
82541PI(ER) and 82562GZ(GX) Dual Footprint LOM Design Guide
B
8 25 6 2 G Z (G X )/
8 2 5 4 1P I(E R )
1 9 6 p in s B G A
C
A
M a g n e tics
M o d u le
P C B E dg e
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