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EVA-7M - Hardware Integration Manual 

UBX-12003235 - R05 

Production Information 

Appendix 

 

 

Page 32 of 42

 

A.5

 

USB self-powered circuit with passive antenna 

 

External LNA 

 

RTC crystal 

 

Backup battery 

 

UART and DDC for communication to host 

 

USB interface 

 

 

Figure 18: USB self-powered circuit 

 

 

Summary of Contents for EVA-7M

Page 1: ...ve EVA 7M GNSS module featuring the u blox 7 positioning engine The EVA 7M module boasts the industry s smallest form factor and is a fully tested standalone solution that requires no host integration...

Page 2: ...er ROM FLASH version PCN reference EVA 7M EVA 7M 0 000 ROM1 00 n a u blox reserves all rights to this document and the information contained herein Products names logos and designs described herein ma...

Page 3: ...3 4 Electromagnetic interference on I O lines 12 2 4 Real Time Clock RTC 12 2 4 1 RTC using a crystal 12 2 4 2 RTC derived from the system clock 13 2 4 3 RTC using an external clock 13 2 4 4 Time aidi...

Page 4: ...uct testing 27 4 1 Test parameters for OEM manufacturer 27 4 2 System sensitivity test 27 4 2 1 Guidelines for sensitivity tests 27 4 2 2 Go No go tests for integrated devices 27 Appendix 28 A Referen...

Page 5: ...ion diode D2 39 B 8 Operational amplifier U6 39 B 9 Open drain buffer U4 U7 and U8 39 B 10 Antenna supervisor switch transistor T1 39 B 11 Ferrite beads FB1 39 B 12 Feed thru capacitors 39 B 13 Induct...

Page 6: ...Like other u blox GNSS modules the EVA 7M uses components selected for functioning reliably in the field over the full operating temperature range The EVA 7M is easily integrated in manufacturing than...

Page 7: ...ek short routing matched impedance and no stubs External LNA With EVA 7M an additional external LNA is mandatory if a passive antenna is used to achieve the performance values as written in the EVA 7M...

Page 8: ...If no backup supply is available connect V_BCKP to VCC_IO Avoid high resistance on the V_BCKP line During the switch from main supply to backup supply a short current adjustment peak can cause high v...

Page 9: ...re For more information see GPS Implementation and Aiding Features in u blox wireless modules 5 The TX Ready feature is supported on version LEON FW 7 xx and LISA U2 01S and above 2 2 1 UART interface...

Page 10: ...interface can be used either in self powered or bus powered mode The required mode can be configured using the UBX CFG USB message Also the vendor ID vendor string product ID and product string can be...

Page 11: ...There is either a 2 pin or a 3 pin antenna supervisor By default the 2 pin antenna supervisor is enabled 2 3 3 1 2 pin antenna supervisor The 2 pin antenna supervisor function which is enabled by defa...

Page 12: ...sing entirely and lines close to the edges of the printed circuit board If a GSM signal radiates into an unshielded high impedance line noise in the order of volts can be generated and possibly not on...

Page 13: ...cation shown in section B 1 2 4 4 Time aiding Time can also be sent by UBX message at every startup of the EVA 7M This can be done to enable warm starts AssistNow Autonomous and AssistNow Offline This...

Page 14: ...To provide additional robustness an ESD protection diode as listed in Appendix B 7 can be placed in front of the LNA to GND 2 5 3 Improved Jamming Immunity If strong out band jammers are close to the...

Page 15: ...ncluding external LNA or the LNA in the active antenna should be around 1 dB With EVA 7M an external LNA is mandatory if no active antenna is used to achieve the performance values as written in the E...

Page 16: ...O Reserved Do not connect Must be left open Reserved I O Reserved Do not connect Must be left open Reserved I O Reserved Do not connect Must be left open Reserved I O Reserved Do not connect Must be...

Page 17: ...ro strip for RF input The micro strip coplanar waveguide must be 50 Ohms and be routed in a section of the PCB where minimal interference from noise sources can be expected Make sure around the RF lin...

Page 18: ...EVA 7M Hardware Integration Manual UBX 12003235 R05 Production Information Design in Page 18 of 42 2 10 1 Footprint Figure 6 Recommended footprint bottom view Units are in mm Pin1 Pin36...

Page 19: ...circuitry that can emit heat The RF part of the receiver is very sensitive to temperature and sudden changes can have an adverse impact on performance High temperature drift and air vents can affect...

Page 20: ...irectly connected to the RF_IN pin an additional LNA in front of C88 7M is recommended in order to achieve the performance values shown in the EVA 7M Data Sheet 1 The Noise Figure of the C88 7M is abo...

Page 21: ...verstress damage during production or in the field it is essential to observe strict EOS ESD EMI handling and protection measures To prevent overstress damage at the RF_IN of your receiver never excee...

Page 22: ...Precautions 2 12 4 Electrical Overstress EOS Electrical Overstress EOS usually describes situations when the maximum input power exceeds the maximum specified ratings EOS failure can happen if RF emi...

Page 23: ...be the SAW Filters from Epcos B9444 or B7839 or Murata 2 12 6 2 Increasing interference immunity Interference signals come from in band and out band frequency sources 2 12 6 3 In band interference Wit...

Page 24: ...c 0 500 1000 1500 2000 GPS input filter characteristics 0 110 0 500 1500 2000 Frequency M Hz GSM 900 GSM 1800 GSM 1900 Pow er dBm GPS input filter characteristics GPS 1575 0 110 GPS signals GSM 950 Fi...

Page 25: ...hen handling patch antennas due to the risk of electrostatic charges In addition to standard ESD safety practices the following measures should be taken into account whenever handling the receiver Unl...

Page 26: ...heat process 3 3 3 Optical inspection After soldering the EVA 7M module consider an optical inspection step to check whether The module is properly aligned and centered over the pads 3 3 4 Repeated re...

Page 27: ...nt Communications Positioning Technology www positioningtechnology co uk Figure 13 Multi GNSS generator 4 2 1 Guidelines for sensitivity tests 1 Connect a Multi GNSS generator to the OEM product 2 Cho...

Page 28: ...hematics A 1 Cost optimized circuit Passive Antenna 1 No RTC crystal No backup battery UART and DDC for communication to host Figure 14 Cost optimized circuit 1 To achieve the performance values as wr...

Page 29: ...ual UBX 12003235 R05 Production Information Appendix Page 29 of 42 A 2 Best performance circuit with passive antenna External LNA RTC crystal Backup battery UART and DDC for communication to host Figu...

Page 30: ...duction Information Appendix Page 30 of 42 A 3 Improved jamming immunity with passive antenna External SAW filter LNA SAW filter RTC crystal Backup battery UART and DDC for communication to host Figur...

Page 31: ...nual UBX 12003235 R05 Production Information Appendix Page 31 of 42 A 4 Circuit using active antenna Active antenna RTC crystal Backup battery UART and DDC for communication to host Figure 17 Standard...

Page 32: ...12003235 R05 Production Information Appendix Page 32 of 42 A 5 USB self powered circuit with passive antenna External LNA RTC crystal Backup battery UART and DDC for communication to host USB interfa...

Page 33: ...al UBX 12003235 R05 Production Information Appendix Page 33 of 42 A 6 USB bus powered circuit with passive antenna External LNA RTC crystal Backup battery SPI for communication to host USB interface F...

Page 34: ...2003235 R05 Production Information Appendix Page 34 of 42 A 7 Circuit using 2 pin antenna supervisor 2 pin antenna supervisor RTC crystal Backup battery UART and DDC for communication to host Figure 2...

Page 35: ...2003235 R05 Production Information Appendix Page 35 of 42 A 8 Circuit using 3 pin antenna supervisor 3 pin antenna supervisor RTC crystal Backup battery UART and DDC for communication to host Figure 2...

Page 36: ...ous operation Family Variant Antenna SAW LNA On chip LNA SAW Passive GNSS Antenna Active GNSS Antenna SAW 2G cellular 3G 4G cellular 2G 3G 4G cellular MAX 6 Any NEO 6 Any LEA 6 Any EVA 7 M MAX 7 C W Q...

Page 37: ...e CL 7 pF 2 2 Equivalent series resistance RS 100 k Table 10 RTC crystal specifications Manufacturer Order No Micro Crystal CC7V T1A 32 768 kHz 7 0 pF 100 ppm Table 11 Recommend parts list for RTC cry...

Page 38: ...gh attenuation only for mobile application muRata SAFFB1G58KB0F0A GPS GLONASS Low insertion loss Only for mobile application Triquint B9850 GPS Compliant to the AEC Q200 standard CTS CER0032A GPS Cera...

Page 39: ...arts list for antenna supervisor switch transistor p channel MOSFET B 11Ferrite beads FB1 Manufacturer Order No Comments MuRata BLM15HD102SN1 High impedance 1 575 GHz MuRata BLM15HD182SN1 High impedan...

Page 40: ...r at VBUS Depends on USB LDO U2 specification Table 25 Standard capacitors B 15Standard resistors Name Use Type Value R1 USB data serial termination 27R 5 0 1W R2 USB data serial termination 27R 5 0 1...

Page 41: ...0 Release Note Docu No GPS G7 SW 12003 For regular updates to u blox documentation and to receive product change notifications please register on our homepage Revision history Revision Date Name Stat...

Page 42: ...ne 65 6734 3811 E mail info_ap u blox com Support support_ap u blox com Regional Office Australia Phone 61 2 8448 2016 E mail info_anz u blox com Support support_ap u blox com Regional Office China Be...

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