NEO-M9N - Integration manual
current should be limited to below 150 mA at the module supply voltage under short-circuit
conditions. For example, a value of 19 Ω or more is required at a module supply of 3.3 V to
limit short-circuit current to 150 mA. The DC resistance of the bias-t inductor is assumed to
be 1-2 Ω and the module internal feed inductor is assumed to be 1.2 Ω.
The power dissipation in the resistor and inductor needs to be taken into account based on
the supply voltage and the short-circuit current.
4.5.3 Out-of-band blocking immunity
Out-of-band RF interference may degrade the quality and availability of the navigation solution.
Out-of-band immunity limit describes the maximum power allowed at the receiver RF input with no
degradation in performance. Minor violation of the immunity limit may reduce C/N0 of the received
signals but does not necessarily affect the overall receiver performance. However, a significant
violation may reduce receiver sensitivity or cause a complete loss of signal reception. The severity of
the interference depends on the repetition rate, frequency, signal level, modulation, and bandwidth
of the signal.
shows a typical out-of-band immunity level for the NEO-M9N RF input. The measurement
is done at room temperature using a continuous-wave (CW) test signal. The immunity limit is
at constant +13 dBm apart from immediate proximity of the GNSS in-band at 1440 MHz. The
integrated LTE band 13 notch and the SAW filters protect the RF input at 787 MHz region. For wide-
band signals such as an LTE signal, the immunity may be reduced.
It is recommended to verify that the receiver performance is not affected or is at an
acceptable level in the presence of interference.
Figure 34: NEO-M9N out-of-band immunity level at 400 - 1460 MHz and 1710 - 3300 MHz. CW test signal is used.
4.6 EOS/ESD precautions
To avoid overstress damage during production or in the field it is essential to observe strict
EOS/ESD/EMI handling and protection measures.
UBX-19014286 - R07
4 Design
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