Mobile Intel Pentium 4 Processor - M and Intel 845MP/MZ Chipset Platform Design Guide

Mobile Intel

Pentium

4 Processor-M and Intel

845MP/845MZ Chipset Platform

Design Guide 135

Figure 69. Critical Dimensions for Component Placement

Gilad

ICH3-M

EEPROM

Phone

RJ11

Magnetics

Module

LPF

Line

RJ11

Table 45. 82562EH Home/PNA* Critical Dimensions for Component Placement

Distance Priority Guideline

B 1 < 1 inch

A 2 < 1 inch

C 3 < 1 inch

9.10.3.6.1. Distance from Magnetic Module to Line RJ11

This distance ‘B’ should be given highest priority and should be less then 1 inch. In regards to trace

symmetry, route differential pairs with consistent separation and with exactly the same lengths and

physical dimensions.

Asymmetrical and unequal length in the differential pairs contribute to common mode noise and this can

degrade the receive circuit performance and contribute to radiated emissions from the transmit side.

9.10.3.6.2. Distance from 82562EH to Magnetic Module

Due to the high-speed of signals present, distance ‘A’ between the 82562EH and the magnetic should

also be less than 1 inch, but should be second priority relative to distance form connects to the magnetic

module.

And in general, any section of trace that is intended for use with high-speed signals should observe

proper termination practices. Proper signal termination can reduce reflections caused by impedance

mismatches between device and traces route. The reflections of a signal may have a high-frequency

component that may contribute more EMI than the original signal itself.