MAX-7 / NEO-7 / LEA-7 - Hardware Integration Manual
GPS.G7-HW-11006-1
Product handling
Page 46 of 55
5.2.12
Use of ultrasonic processes
Some components on the u-blox 7 module are sensitive to Ultrasonic Waves. Use of any Ultrasonic Processes
(cleaning, welding etc.) may cause damage to the GPS/GNSS Receiver.
u-blox offers no warranty against damages to the u-blox 7 module caused by any Ultrasonic Processes.
5.3
EOS/ESD/EMI precautions
When integrating GPS/GNSS positioning modules into wireless systems, careful consideration must be given to
electromagnetic and voltage susceptibility issues. Wireless systems include components, which can produce
Electrical Overstress (EOS) and Electro-Magnetic Interference (EMI). CMOS devices are more sensitive to such
influences because their failure mechanism is defined by the applied voltage, whereas bipolar semiconductors
are more susceptible to thermal overstress. The following design guidelines are provided to help in designing
robust yet cost effective solutions.
To avoid overstress damage during production or in the field it is essential to observe strict
EOS/ESD/EMI handling and protection measures.
To prevent overstress damage at the RF_IN of your receiver, never exceed the maximum input
power (see Data Sheet).
5.3.1
Electrostatic discharge (ESD)
Electrostatic discharge (ESD) is the sudden and momentary electric current that flows between
two objects at different electrical potentials caused by direct contact or induced by an
electrostatic field. The term is usually used in the electronics and other industries to describe
momentary unwanted currents that may cause damage to electronic equipment.
5.3.2
ESD handling precautions
ESD prevention is based on establishing an Electrostatic Protective Area (EPA). The EPA can be a small working
station or a large manufacturing area. The main principle of an EPA is that there are no highly charging materials
near ESD sensitive electronics, all conductive materials are grounded, workers are grounded, and charge build-up
on ESD sensitive electronics is prevented. International standards are used to define typical EPA and can be
obtained for example from International Electrotechnical Commission (IEC) or American National Standards
Institute (ANSI).
GPS/GNSS positioning modules are sensitive to ESD and require special precautions when handling. Particular
care must be exercised when handling patch antennas, due to the risk of electrostatic charges. In addition to
standard ESD safety practices, the following measures should be taken into account whenever handling the
receiver.
•
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.
