Specifications

PLS63-W Hardware Interface Overview
2.3 GNSS Antenna Interface
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Figure 20 shows a sample circuit realizing ESD protection for a passive GNSS antenna. Con-
necting the input ANT_GNSS_DC to GND prevents ESD from coupling into the module.
Figure 20: ESD protection for passive GNSS antenna
2.3.1 GNSS Antenna Diagnostic
GNSS antenna diagnosis does require an external detection circuit. The antenna DC supply
current can be measured via ADCx_IN. The ADCx_IN input voltage (Ug) may be generated by
a sample circuit shown in Figure 19. The circuit allows to check the presence and the connec-
tion status of an active GNSS antenna. Passive GNSS antennas cannot be detected. There-
fore, GNSS antenna detection is only available in active GNSS antenna mode. This mode is
configured by the AT command: AT^SGPSC (for details see [1])
Having enabled the active GNSS antenna mode the presence and connection status of an ac-
tive GNSS antenna can be checked using the AT command AT^SRADC to monitor ADCx_IN.
The following table lists sample current ranges for possible antenna states as well as sample
voltage ranges as possible decision thresholds to distinguish between the antenna connection
states. Please refer to [1] for more information on the command AT^SRADC.
Table 6: Sample ranges of the GNSS antenna diagnostic measurements and their possible meaning
Antenna connection status Current ranges (I
S
)
1
1. Please note that the mA ranges 1.4mA...2.2mA and 20mA...30mAare tolerance ranges. The decision
threshold should be defined within these ranges.
Voltage ranges (U
G
)
Antenna not connected <1.4mA
Decision threshold 59mV ±20%
Antenna connected 2.2mA...20mA
Decision threshold 825mV ±20%
Antenna short circuited to ground >30mA
GNSS antenna detection is not possible because
GNSS antenna power supply is switched off.
--
VGNSS
ANT_GNSS
Passive
GNSS
antenna
10nH
100nF
To GNSS
receiver
Module
SMT interface
ANT_GNSS_DC
(Optional)
ESD
protection
0R
Not used
22p+
100n