u-blox ANTARIS 4, System Integration Manual

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References Value Tolerance Description Remarks
C 2.2 µF
±
1
Capacitor, X7R, min 10 V 1
0%
C2 100 nF
±
1
Capacitor, X7R, min 10 V
0%
FB1
600
Ω
Ferrite Bead e.g. Murata BLM18HD601SN1
R1
56
Ω ±
10%
Resistor, min 0.063 W
R2
10
Ω ±
10%
Resistor, min 0.250 W
R3, R4
5.6 k
Ω ±
1
Resistor, min 0.063 W
0%
R5
O
Ω
or
47 k
Ω
±
1
Resistor, min 0.063 W
Use 0
Ω
if antenna voltage supply is <4.5V.
Otherwise, use a 47k resistor.
0%
T1, T2 PNP Transistor BC856B e.g. Philips Semiconductors
8
Table 19: Active Antenna Supervisor, bill of material
Short Circuit Detection (SCD)
A short circuit in the active antenna pulls V_ANT to ground. This is detected inside the ANTARIS
®
4 GPS module
and the antenna supply voltage will be immediately shut down.
Note Antenna short detection (SCD) and control is enabled by default.
Open Circuit Detection (OCD)
The open circuit detection circuit uses the current flow to detect an open circuit in the antenna. The threshold
current is at 3-5mA. A current below 3mA will definitely indicate an open circuit. A current above 5mA will
definitely indicate no open circuit (values apply for R2=10
Ω
voltage drop through R4 and therefore ADDET_N will be high, indicating
an open connection. On the other hand, if the current is small, ADDET_N will be low.
e antenna open circuit detection (OCD) is disabled by default, on
Rep
At startup a le will output
a NMEA ($GPTXT) or UBX (INF-NOTICE) message with the internal status of the antenna supervisor (disabled,
short detection only, enabled).
strings below are part of this message to inform about the status of the active
).
If the current through T2 is large, the
Note On Programmable GPS Modules th
Low Cost modules it’s enabled.
Status orting
nd on every change of the antenna supervisor configuration the ANTARIS
®
4 GPS modu
None, one or several of the
antenna supervisor circuitry (e.g. “ANTSUPERV= AC SD OD PdoS”).
Abbreviation Description
AC Antenna Control (e.g. the antenna will be switched on/ off controlled by the GPS
receiver)
SD Short Circuit Detection Enabled
OD Open Circuit Detection Enabled
PdoS Power Down on short
Table 20: Active Antenna Supervisor Message on startup (UBX binary protocol)
8
Transistors from other suppliers with comparable electrical characteristics may be used.
GPS Modules - System Integration Manual (SIM) (incl. Reference Design) Receiver Description
GPS.G4-MS4-05007-A1 Page 78