Power And Ground Connections; General Power And Ground Plane Consideration; Ground Plane Separation - Intel Pentium M Processor Design Manual

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Intel Pentium M Processor and Intel
I/O Controller Hub 3 (Intel
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Physically group together all components associated with one clock trace to reduce trace
length and radiation.
•
Isolate I/O signals from high speed signals to minimize crosstalk, which may increase EMI
emission and susceptibility to EMI from other signals.
•
Avoid routing high-speed LAN or Phoneline traces near other high-frequency signals
associated with a video controller, cache controller, processor, or other similar devices.
9.7.2.4

Power and Ground Connections

Follow these rules for power and ground connections:
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All VCC balls should be connected to the same power supply.
•
All VSS balls should be connected to the same ground plane.
•
Four to six decoupling capacitors, including two 4.7 µF capacitors, are recommended.
•
Place decoupling as close as possible to power balls.
9.7.2.5

General Power and Ground Plane Consideration

To properly implement the common mode choke functionality of the magnetics module, the chassis
or output ground (secondary side of transformer) should be separated from the digital or input
ground (primary side) by a physical separation of 100 mils minimum.
plane separation.
Figure 121.

Ground Plane Separation

Good grounding requires minimizing inductance levels in the interconnections and keeping ground
returns short, signal loop areas small, and power inputs bypassed to signal return. These may
significantly reduce EMI radiation.
172
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E7501 Chipset Platform
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ICH3-S)
Separate C hassis
Ground Plane
Figure 121
0.10" m inim um Separation
M agnetics M odule
Ground Plane
shows the ground
Design Guide