PAM-7Q - Hardware Integration Manual
UBX-13003143 - R06
Early Production Information
Product handling
Page 18 of 26
Unless there is a galvanic coupling between the local GND (i.e. the
work table) and the PCB GND, then the first point of contact when
handling the PCB must always be between the local GND and PCB
GND.
Before mounting an antenna patch, connect ground of the device
When handling the RF pin, do not come into contact with any
charged capacitors and be careful when contacting materials that
can develop charges (e.g. patch antenna ~10 pF, coax cable ~50 -
80 pF/m, soldering iron, …)
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!
5.3.3
ESD protection measures
GNSS positioning modules are sensitive to Electrostatic Discharge (ESD). Special precautions
are required when handling.
5.3.4
Electromagnetic interference (EMI)
Electromagnetic interference (EMI) is the addition or coupling of energy originating from any RF emitting device.
This can cause a spontaneous reset of the GNSS receiver or result in unstable performance. Any unshielded line
or segment (>3mm) connected to the GNSS receiver can effectively act as antenna and lead to EMI disturbances
or damage.
The following elements are critical regarding EMI:
Unshielded connectors (e.g. pin rows etc.)
Weakly shielded lines on PCB (e.g. on top or bottom layer and especially at the border of a PCB)
Weak GND concept (e.g. small and/or long ground line connections)
EMI protection measures are recommended when RF emitting devices are near the GNSS receiver. To minimize
the effect of EMI a robust grounding concept is essential. To achieve electromagnetic robustness follow the
standard EMI suppression techniques.
http://www.murata.com/products/emc/knowhow/index.html
http://www.murata.com/products/emc/knowhow/pdf/4to5e.pdf
Improved EMI protection can be achieved by inserting a resistor (e.g. R>20
) or better yet a ferrite bead
(BLM15HD102SN1) or an inductor (LQG15HS47NJ02) into any unshielded PCB lines connected to the GNSS
receiver. Place the resistor as close as possible to the GNSS receiver pin.
