MAX-7 / NEO-7 - Hardware Integration Manual
UBX-13003704
-
R09
Production Information
Product
handling
Page
43 of 52
To prevent electrostatic discharge through the RF input, do not
touch any exposed antenna area. If there is any risk that such
exposed antenna area is touched in non ESD protected work area,
implement proper ESD protection measures in the design.
When soldering RF connectors and patch antennas to the receiver’s
RF pin, make sure to use an ESD safe soldering iron (tip).
Failure to observe these precautions can result in severe damage to the GNSS module!
7.3.3
ESD protection measures
GNSS positioning modules are sensitive to Electrostatic Discharge (ESD). Special precautions are
required when handling.
For more robust designs, employ additional ESD protection measures. Using an LNA with appropriate ESD
rating can provide enhanced GNSS performance with passive antennas and increases ESD protection.
Most defects caused by ESD can be prevented by following strict ESD protection rules for production and
handling. When implementing passive antenna patches or external antenna connection points, then additional
ESD measures as shown in Figure 32 can also avoid failures in the field.
Small passive antennas
(<2 dBic
and performance critical)
Passive antennas
(>2 dBic or
performance sufficient)
Active antennas
A
RF
_
IN
G
P
S
R
e
c
e
iv
e
r
LNA
B
L
RF
_
IN
G
P
S
R
e
c
e
iv
e
r
C
D
RF
_
IN
G
P
S
R
e
c
e
iv
e
r
LNA with appropriate ESD rating
Figure 32: ESD Precautions
Protection measure A is preferred because it offers the best GNSS performance and best level of ESD
protection.
7.3.4
Electrical Overstress (EOS)
Electrical Overstress (EOS) usually describes situations when the maximum input power exceeds the maximum
specified ratings. EOS failure can happen if RF emitters are close to a GNSS receiver or its antenna. EOS causes
damage to the chip structures. If the RF_IN is damaged by EOS, it is hard to determine whether the chip
structures have been damaged by ESD or EOS.
7.3.5
EOS protection measures
For designs with GNSS positioning modules and cellular (e.g. GSM/GPRS) transceivers in close proximity,
ensure sufficient isolation between the cellular and GNSS antennas. If cellular power output causes the
specified maximum power input at the GNSS RF_IN to be exceeded, employ EOS protection measures to
prevent overstress damage.
