User Manual

Iridium Communications, Inc. Information Contained in this Guide
Iridium 9523 Product Developers’ Guide is Subject to Change Without Notice
Revision 2.6
Iridium Communications, Inc. Distribution of Guide Restricted
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Only
Figure 3: Illustration of mounting module to application board
The FA board must have a socket mating to the Molex 40-pin multi-way user interface connector on the
bottom of the 9523. See section 3.1.1 for the connector part number. The Molex connectors and
aluminum frame set the separation between the Iridium 9523 and FA boards at 2.5 mm.
In order to meet type approval standards for EMC, the FA board should include a ground ring and a good
ground layer on its top surface to act as the fifth side of the screening can.
The layout of the mounting location for the 9523 on the FA board – including the locations and diameters
of all nine holes, layout of the grounding ring, and identification of areas with different grounding
requirements – is shown in Figure 4. A CAD file showing this information in DXF format can be obtained
from Iridium in order to assist layout of FA boards.
The FA board must have screw holes lining up with the 9523’s four 1.8mm corner mounting screw holes.
The 9523 must be secured to the FA board with four M1.6x0.35 screws through these holes. The FA
board must also have four corner alignment holes and one center alignment hole lining up, respectively,
with the 9523’s four 1.6mm corner protruding screws and one 1mm center alignment pin. The screw
holes should be at least 1.8mm and the alignment hole at least 1.2mm, but they may be made slightly
larger for greater tolerance. In Figure 4 below, one of the screw holes is 2.08mm, providing the primary
alignment, while the other three screw holes are 2.1mm. In the same figure, the center alignment hole is
1.3mm. These dimensions are recommendations; other dimensions may be used so long as the 9523 is
properly aligned with the user interface connector and ground trace.
In Figure 4, area ‘A’ of the FA board sits under sensitive analog circuitry on the 9523’s bottom side, and it
is essential that no components or tracks on the FA board appear in this area; it must be filled entirely
with a solid ground plane on the top layer of the FA board.
Area ‘D’ sits under digital and power circuits. Ideally, this will also be shielded with a solid ground plane.
However, it is acceptable to place tracks and low-profile components in area ‘D’, so long as care is taken
to avoid mechanical clashes and due consideration is taken of EMC issues.
Area ‘C’ contains the Molex user interface connector and should be free of surface copper.