u-blox ANTARIS 4 - Page 50

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Standard Function Remarks
No Name I/O Description 
1
BOOT_INT I Bootmode Leaveopen
2
SELECTModeSelectorPin
EEPROMisused.Neverleavethispinopen.
TheSELECTpinallowsselectionbetweenusingthedefaultconfiguration(Battery
BackupRAM)orconfigurationstorageinanexternalEEPROM(seealsosection
4.8).ConnecttoVCCifdefaultconfigurationisdesired.ConnectGNDifexternal
gofpin16(SCK / CFG_USB)dependsonthestatusofthe

Note:
Themeanin
SELECTpin.
3
TIMEPULSE O Timepulse(1PPS)
notused.SeealsoSection 4.7.1.
ConfigurableTimepulsesignal(onepulsepersecondbydefault).Leaveopenif
4
EXTINT0 I ExternalInterruptPin
ExternalInterruptPintowakeupreceiverinFixNOW™sleepmode.Seealso
Section 4.2.7.1and4.9.4forfurtherinformation.
Internalpull-upresistorto V_BAT
7
.Leaveopenifnotused.
5
USB_DM I/O USBData
6
aticrecommendationinSection 4.4.2.
USB_DP I/O USBData
USB1.1bidirectionalcommunicationpin.TobefullycompliantwithUSBstandard
followtheschem
7
VDDUSB I USBSupply
If
TousetheUSBinterfaceconnectthispinto3.0–3.6V.SeealsoSection 4.4.2.
noUSBserialportusedconnecttoGND.
8
(Reserved) I Reserved
9
externalactiveantenna.
VCC_RF O
OutputVoltageRF
section
Pins8and9havetobeconnec ted.VCC_RFcanalsobeusedtopoweran
10
GND I Ground
AssureagoodGNDconnectiontoallGNDpinsofthemodule,preferablywitha
largegroundplane(fordetailsrefertoSection 0)
11
RF_IN I GPSsignalinput
TheconnectiontotheantennahastoberoutedonthePCB.Use acontrolled
impedanceof50OhmtoconnectRF_INtotheantennaortheantennaconnector
(fordetailsrefertoSection 3.6.5)
12
fertopin10.GND I Ground Re
13
GND I Ground Refertopin10.
14
MOSI O SPIMOSI
15
MISO I SPIMISO
LeaveopenifSPIinterfaceisnotused.Contactu-bloxformo reinformation
abouttheSPIinterface.
16
SCK/CFG_USB O/I
SPIClock/
USBPowerMode

Thefunctionofpin16dependsonthestatusoftheSELECTpin:
• If SELECT pin is connected to VCC:
Pin16isaconfigurationinput,whichdefinestheUSBPowerMode.Connect
toGNDforBus-P oweredUSBinterface.LeaveopenifUSBinterfaceSelf-
Powered
• If SELECT pin is connected to GND:
Pin16isinternallyconnectedtotheSCK(SPIclocksignal).Contactu-bloxfor
moreinformationabouttheSPIinterface.
17
NCS O SPIchipselect
LeaveopenifSPIinterfaceisnotused.Contactu-bloxformo reinformation
abouttheSPIinterface.
18
(Reserved) I Leaveopen
19
(Reserved) I NC Leaveopen
20
TxD1 O SerialPort1 3VLevel
21
RxD1 I SerialPort1
5Vtolerantserialinput.Internalpull-upresistorto V_BAT.Leaveopenifnot
used.
Note Don’tuseanexternalpullupresistor.
22
V_BAT I
Backupvoltage
supply
It’srecommendedtoconnectabackupbatterytoV_BATinordertoenable
WarmandHotStartfeaturesonthereceivers.SeealsoSection 4.2.2.Otherwise
connecttoGND.
23
VCC I Supplyvoltage
MaxallowedrippleonVCC=50mVpp
24
GND I Ground Refertopin10.
Table 7: Pin-out NEO-4S

7
DonotpullupasitmayincreaseyourBatteryBackupCurrent.
GPSModules-SystemIntegrationManual(SIM)(incl.ReferenceDesign) Design-In
GPS.G4-MS4-05007-A1
  Page 50