EVA-M8M - Hardware Integration Manual
UBX-14006179 - R02
Early Production Information
Design-in
Page 24 of 45
2.13
EOS/ESD/EMI precautions
When integrating GNSS receivers into wireless systems, careful consideration must be given to electromagnetic
and voltage susceptibility issues. Wireless systems include components which can produce Electrostatic Discharge
(ESD), 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 as
specified in the
EVA-M8M Data Sheet
2.13.1
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.
2.13.2
ESD protection measures
GNSS receivers are sensitive to Electrostatic Discharge (ESD). Special precautions are required when
handling.
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 6 can also avoid failures in the field.
Passive antennas
Active Antennas
A
B
LNA with appropriate ESD rating
RF ESD protection diode
Figure 6: ESD Precautions
2.13.3
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’s hard to determine whether the chip structures have been damaged by ESD
or EOS.
