Specifications

WA_DEV_FEX20_PTS_004 Rev 001 June 30, 2010 45
8. Design Guidelines
8.1. EMC Recommendations
EMC tests must be performed on the application as soon as possible to detect any potential
problems.
When designing, special attention should be paid to:
 Possible spurious emission radiated by the application to the RF receiver in the receiver band
 ESD protection is mandatory on all signals which are externally accessible. Typically, ESD
protection is mandatory for an IO Expander Connector.
 Ground plane: Sierra Wireless recommends a common ground plane for analog/digital/RF
grounds and the IESM board must be properly grounded with Fastrack Xtend metallic
housing.
Tip: In order for the Expansion Card to have the best grounding, Sierra Wireless recommends attaching
the ground plane of the PCB to the back plate instead of on the Fastrack Xtend’s main housing.
Expansion Cards designed by Sierra Wireless achieves this by using a metallic spring that attaches to
the middle screw of the back plate.