Antenna Interface Precautions - u-blox LISA-C2 Series System Integration Manual

Reference Description
ESD Varistor for ESD protection.
C1, C2 47 pF Capacitor Ceramic C0G 0402 5% 50 V
FB1, FB2 Chip Ferrite Bead for Noise/EMI Suppression
Rint 10 kΩ Resistor 0402 5% 0.1 W
Table 34: Example of components as ESD immunity test precautions for the HW_SHUTDOWN line
SIM interface
Sensitive interface is the SIM interface (VSIM pin, SIM_RST pin, SIM_IO pin, SIM_CLK pin):
•
A 47 pF bypass capacitor (e.g. Murata GRM1555C1H470J) have to be mounted on the lines connected to
VSIM, SIM_RST, SIM_IO and SIM_CLK to assure SIM interface functionality when an electrostatic discharge
is applied to the application board enclosure.
•
It is suggested to use as short as possible connection lines at SIM pins.
SIM card interface is supported in software only by LISA-C200 versions 03S/23S onwards

2.5.2 Antenna interface precautions

The antenna interface ANT can have a critical influence on the ESD immunity test depending on the application
board handling. Antenna precaution suggestions are provided:
•
If the device implements an embedded antenna and the device insulating enclosure avoids air discharge up
to +8 kV / -8 kV to the antenna interface, no further precautions to ESD immunity test should be needed.
•
If the device implements an external antenna and the antenna and its connecting cable are provided with a
completely insulating enclosure to avoid air discharge up to +8 kV / -8 kV to the whole antenna and cable
surfaces, no further precautions to ESD immunity test should be needed.
•
If the device implements an external antenna and the antenna or its connecting cable are not provided with
completely insulating enclosure to avoid air discharge up to +8 kV / -8 kV to the whole antenna and cable
surfaces, the following precautions to ESD immunity test should be implemented on the application board.
A higher protection level is required at the ANT port if the line is externally accessible on the application board.
ESD immunity test requires protection up to +4 kV / -4 kV for direct Contact Discharge and up to +8 kV / -8 kV
for Air Discharge applied to the antenna port. One possible suggested solution for higher protection is to
implement an external high pass filter, consisting of a series 15 pF capacitor (Murata GRM1555C1H150JA01)
and a shunt 39 nH coil (Murata LQG15HN39NJ02) at the antenna port as described in Figure 38 and Table 35.
Antenna detection functionality is not provided when implementing the high pass filter described in Figure
38 and Table 35., as ESD protection for the antenna port LISA-C200 / FW75-C200.
UBX-13000620 - R21
LISA-C2 series and FW75-C200 - System Integration Manual
Remarks
CT0402S14AHSG - EPCOS
GRM1555C1H470JA01 - Murata
BLM15HD182SN1 - Murata
Internal pull-up resistor
Early Production Information Design-In
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