Termination Plane Capacitance; Figure 127. Termination Plane - Intel Pentium 4 Design Manual

R
9.9.4.6.1

Termination Plane Capacitance

It is recommended that the termination plane capacitance equal a minimum value of 1500 pF. This
helps reduce the amount of crosstalk on the differential pairs (TDP/TDN and RDP/RDN) from the
unused pairs of the RJ45. Pads may be placed for an additional capacitance to chassis ground,
which may be required if the termplane capacitance is not large enough to pass EFT (Electrical
Fast Transient) testing. If a discrete capacitor is used, to meet the EFT requirements it should be
rated for at least 1000 Vac.

Figure 127. Termination Plane

TDP
TDN
RDP
RDN
® ®
Intel Pentium 4 Processor / Intel
N/C
Magnetics m odule
Term ination plane
®
850 Chipset Family Platform Design Guide
I/O Controller Hub 2
Additional capacitance that m ay be
required for EFT testing
RJ-45
LAN_term_plane
179