Intel 6300ESB ICH, Design Manual

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Intel
®
855GME Chipset and Intel
®
6300ESB ICH Embedded Platform Design Guide
Intel
®
6300ESB Design Guidelines
Note: It is highly recommended that the fuse element (thermistor) for the front panel header be included
on the motherboard to protect the motherboard from damage in the following instances:
1. If an un-fused front panel cable solution is used.
2. If an un-keyed cable is inadvertently plugged onto the front panel USB connector.
3. If the front panel cable is cut or damaged during assembly or manufacturing resulting in a
short between V
BUS
and ground.
9.6.6.2.2 Routing Considerations
Traces or surface shapes from V
CC
to the thermistor, to C
BYPASS
and to the connector power and
ground pins should be at least 50 mils wide to ensure adequate current carrying capability. There
should be double vias on power and ground nets, and the trace lengths should be kept as short as
possible.
9.6.6.3 Front Panel Connector Card
The best way to provide front or side panel support for USB is to use a daughter card and cable
assembly. This allows the placement of the EMI/ESD suppression components right at the USB
connector where they will be the most effective.
Figure 113 shows the major components
associated with a typical front/side panel USB solution that uses a front panel connector card. For
more information refer to the Intel FPIO design guideline available at:
http://www.formfactors.org/developer/specs/fpio_design_guideline.pdf .
Figure 112. Front Panel Header Schematic
B1164-01
KEY
DM1
DP1
THRMSTR 1.54 for two ports
120 µF per hub
GND
DM2
DP2
GND
NC or Overcurrent
C
bypass
Vbus
V
CC
3 4
1 2
5 6
7 8
9 10