Intel ® 82562Et/Em Termination Resistors; Critical Dimensions; Intel ® 82562Et/Em Termination; Critical Dimensions For Component Placement - Intel Xeon Design Manual

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9.7.3.3 Intel 82562ET/EM Termination Resistors
The 100 Ω ± 1% resistor used to terminate the differential transmit pairs (TDP/TDN), and the
121 Ω ± 1% resistor used to terminate the differential receive pairs (RDP/RDN) should be placed
as close to the Platform LAN connect component (82562ET or 82562EM) as possible. This is due
to the fact that these resistors are terminating the entire impedance that is seen at the termination
source (i.e., 82562ET), including the wire impedance reflected through the transformer.
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Figure 9-19. Intel
9.7.4

Critical Dimensions

There are two dimensions to consider during layout. Distance 'A' from the line RJ45 connector to
the magnetics module, and distance 'B' from the 82562ET or 82562EM to the magnetics module.
The combined total distances A and B must not exceed 2 inches. (See
Figure 9-20. Critical Dimensions for Component Placement
Intel
ICH3-S
EEPROM
Design Guide
82562ET/EM Termination
LAN Connect
Interface
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Intel
82562ET
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Intel
82562ET
M agnetics
m odule
Place term ination resistors as
close as possible to 82562ET.
B < 1"
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Magnetics
Module
I/O Controller Hub
RJ45
Figure 9-20.)
A < 1"
Line
RJ45
143