u-blox ANTARIS 4 - Page 78

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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BL M18HD601SN1
R1
56Ω ±10%
Resistor,min0.063W

R2
10Ω ±10%
Resistor,min0.250W

R3,R4
5.6kΩ ±1
Resistor,min0.063W
0%
R5
OΩor
47kΩ
±1
Resistor,min0.063W
Use0Ωifantennavoltagesupplyis<4.5V.
Otherwise,usea47kresistor.
0%
T1,T2  PNPTransistorBC856B e.g.PhilipsSemiconductors
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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)

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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