u-blox ANTARIS 4 - Active Antenna Supervisor


your position is our focus
4.3.3.2 Short Circuit Protection
This section only applies to TIM-4x and LEA-4x receivers with the exception of LEA-4M.
Ifareasonably dimensionedseries resistorR_BIASisplacedinfrontofpinV_ANT,ashortcircuitsituationcan
bedetected bythebaseband processor.Ifsuch asituationis detected,thebaseband processorwill shutdown
supplytotheantenna.Forfirmwareversionearlierthan5.00,thevoltage
supplytotheantennawill onlybere-
establishedafterahardwareresetofthereceiver,e.g.afterpowercycling.Forfirmwareversion5.00orlaterthe
receivercanbeconfiguredtoattempttoreestablishantennapowersupplyperiodically.
 Note ToconfiguretheantennasupervisorusetheUBX-CFG-ANTmessage.Forfurtherinformationreferto
the ANTARIS
®
4 Protocol Specification.
References Value Tolerance Description Manufacturer
R_BIAS
10Ω ±10%
Resistor,min0.250W
Table 18: Short circuit protection, bill of material
! Warning Shortcircuitsontheantennainputwithoutlimitationofthecurrentcanresultinpermanentdamage
tothereceiver!Therefore,it’srecommendedtoimplementanR_BIASinallriskapplications,suchas
situationswheretheantennacanbedisconnectedbytheend-userorthathavelongantennacables.
 Note An
additionalR_BIASisnotrequiredwhenusingashortandopenactiveantennasupervisorcircuitry
asdefinedinSection 4.3.4.1,astheR_BIASisequaltoR2.
 for LEA-4M and NEO-4S. However, both modules still output antenna
ys STA
4.3.4 Active Antenna Supervisor
TheANTARIS
®
4GPSTechnologyprovidesthemeanstoimplementanactiveantennasupervisorwithaminimal
numberofparts.Theantennasupervisorishighlyconfigurabletosuitvariousdifferentapplications.
Note This feature is not available
status messages. NEO-4S alwa  reports “ANT TUS=OK” whereas
LEA-4S will always report
“ANTSTATUS=SHORT”.Bothmessagesshallbeignored.
ANTARIS GPS Module
GND
RF_IN
GND
Active Antenna
V_ANT
VCC_RF
LNA
AADET_N
Antenna
Supervisor
Circuitry
external
antenna
voltage
supply

Figure 63: External antenna power supply with full antenna supervisor
GPSModules-SystemIntegrationManual(SIM)(incl.ReferenceDesign) ReceiverDescription
GPS.G4-MS4-05007-A1
  Page 75