Usb 2.0 Termination; Usb 2.0 Trace Length Pair Matching; Usb 2.0 Trace Length Guidelines; Usb Bias Connections - Intel 855GME Design Manual

®
Intel 855GME Chipset and Intel
®
Intel 6300ESB Design Guidelines
Figure 109.

USB BIAS Connections

Table 82.

USB BIAS Routing Summary

Trace
Impedance
55 Ω ± 10%
9.6.1.4

USB 2.0 Termination

A common-mode choke should be used to terminate the USB 2.0 bus. Place the common-mode
choke as close as possible to the connector pins. See
page 214
9.6.1.5

USB 2.0 Trace Length Pair Matching

USB 2.0 signal pair traces should be trace length matched. Max trace length mismatch between
USB 2.0 signal pair should not be greater that 60 mils.
9.6.1.6

USB 2.0 Trace Length Guidelines

Table 83
Platforms With A Nominal Impedance Of 55 Ω ± 10% (Microstrip)
9.6.1.6.1
USB 2.0 Back Panel Trace Length Guidelines (Common-mode Choke, 55 Ω ± 10%)
Table 83.
Differential
Impedance
100 ± 10%
NOTE: Two options are given for motherboard trace length, choose the parameters that best suit your system.
212
®
6300ESB ICH Embedded Platform Design Guide
USBRBIAS/USBRBIAS#
Routing Requirements
5 mils width, 5 mils spacing
for details.
and Table 84 provide trace length guidelines.
Pair Spacing
45 mils
80 mils
Maximum Trace
Length
500 mils
Section 9.6.4, "EMI Considerations" on
Signal
Signal Matching
Referencing
The max mismatch
between data pairs
Ground
should not be greater
than 60 mils
Signal Length Signal
Matching Referencing
N.A. N.A.
Maximum
Motherboard Trace
Length
7.4 inches
10.1 inches