Integration Manual

SARA-R4/N4 series - System Integration Manual
UBX-16029218 - R13 Design-in Page 83 of 119
2.9 Reserved pins (RSVD)
SARA-R4/N4 series modules have pins reserved for future use, marked as RSVD.
All the RSVD pins are to be left unconnected on the application board, except for the RSVD pin number 33 that can be
externally connected to ground.
2.10 Module placement
An optimized placement allows a minimum RF line’s length and closer path from DC source for VCC.
Make sure that the module, analog parts and RF circuits are clearly separated from any possible source of radiated energy.
In particular, digital circuits can radiate digital frequency harmonics, which can produce Electro-Magnetic Interference
that affects the module, analog parts and RF circuits’ performance. Implement suitable countermeasures to avoid any
possible Electro-Magnetic Compatibility issue.
Make sure that the module, RF and analog parts / circuits, and high speed digital circuits are clearly separated from any
sensitive part / circuit which may be affected by Electro-Magnetic Interference, or employ countermeasures to avoid any
possible Electro-Magnetic Compatibility issue.
Make sure that the module is placed in order to keep the antenna as far as possible from VCC supply line and related
parts (refer to Figure 28), from high speed digital lines (as USB) and from any possible noise source.
Provide enough clearance between the module and any external part: clearance of at least 0.4 mm per side is
recommended to let suitable mounting of the parts.
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☞ The heat dissipation during continuous transmission at maximum power can significantly raise the temperature of
the application base-board below the SARA-R4/N4 series modules: avoid placing temperature sensitive devices close
to the module.