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EVA-M8M - Hardware Integration Manual 

UBX-14006179 - R02 

Early Production Information 

Design-in 

 

 

Page 26 of 45

 

 

Figure 9: In-band interference sources 

Measures against in-band interference include: 

•

 

Maintaining a good grounding concept in the design 

•

 

Shielding 

•

 

Layout optimization 

•

 

Filtering  

•

 

Placement of the GNSS antenna 

•

 

Adding a CDMA, GSM, WCDMA bandbass filter before handset antenna 

2.13.5.4

 

Out-band interference 

Out-band interference is caused by signal frequencies that are different from the GNSS carrier (see Figure 10). 
The main sources are wireless communication systems such as GSM, CDMA, WCDMA, WiFi, BT, etc. 

0

500

1000

1500

2000

GPS input filter
characteristics

0

-110

0

500

1500

2000

Frequency [MHz]

GSM

900

GSM

1800

GSM

1900

Power [dBm]

GPS input filter
characteristics

GPS

1575

0

-110

GPS

signals

GSM

950

 

Figure 10: Out-band interference signals 

Measures against out-band interference include maintaining a good grounding concept in the design and 
adding a SAW or bandpass ceramic filter (as recommend in section 2.14.5) into the antenna input line to the 
GNSS receiver (see Figure 11). 

 

Figure 11: Measures against out-band interference 

 

Summary of Contents for EVA-M8M

Page 1: ...EVA M8M concurrent GNSS modules featuring the u blox M8 positioning engine The EVA M8M series boasts the industry s smallest form factor and is a fully tested standalone solution that requires no host integration The EVA M8M modules combine exceptional GNSS performance with highly flexible power design and serial communication options www u blox com UBX 14006179 R02 ...

Page 2: ...ASH version PCN reference EVA M8M EVA M8M 0 00 ROM 2 01 Flash FW 2 01 N A EVA M8M EVA M8M 1 00 ROM 2 01 Flash FW 2 01 N A u blox reserves all rights to this document and the information contained herein Products names logos and designs described herein may in whole or in part be subject to intellectual property rights Reproduction use modification or disclosure to third parties of this document or...

Page 3: ...highlight important information within the manual An index finger points out key information pertaining to module integration and performance A warning symbol indicates actions that could negatively influence or damage the module Questions If you have any questions about EVA M8M integration please Read this manual carefully Contact our information service on the homepage http www u blox com Read t...

Page 4: ...ime pulse 13 2 3 2 External interrupt 13 2 3 3 Active antenna supervisor 13 2 3 4 Electromagnetic interference on I O lines 14 2 4 Real Time Clock RTC 14 2 4 1 RTC using a crystal 15 2 4 2 RTC derived from the system clock 15 2 4 3 RTC using an external clock 15 2 4 4 Time aiding 15 2 5 RF input 16 2 5 1 Active Antenna 16 2 5 2 Passive Antenna 16 2 5 3 Improved Jamming Immunity 16 2 6 Safe Boot Mo...

Page 5: ...3 4 Repeated reflow soldering 28 3 3 5 Wave soldering 28 3 3 6 Rework 28 3 3 7 Conformal coating 28 3 3 8 Casting 28 3 3 9 Use of ultrasonic processes 28 4 Product testing 29 4 1 Test parameters for OEM manufacturer 29 4 2 System sensitivity test 29 4 2 1 Guidelines for sensitivity tests 29 4 2 2 Go No go tests for integrated devices 29 Appendix 30 A Reference schematics 30 A 1 Cost optimized circ...

Page 6: ... U2 40 B 6 External LNA U1 40 B 7 Optional SQI Flash U3 41 B 8 RF ESD protection diode D2 41 B 9 Operational amplifier U6 41 B 10 Open drain buffer U4 U7 and U8 41 B 11 Antenna supervisor switch transistor T1 41 B 12 Ferrite beads FB1 41 B 13 Feed thru capacitors 42 B 14 Inductor L 42 B 15 Standard capacitors 42 B 16 Standard resistors 42 Appendix 43 C Glossary 43 Related documents 44 Revision his...

Page 7: ... for reliable positioning The EVA M8M series comes in two variants The EVA M8M 0 defaults to GPS QZSS GLONASS and fits global applications whereas EVA M8M 1 defaults to GPS QZSS BeiDou making it the ideal module for China The right satellite constellations can be selected without touching software and therefore reducing the design and testing effort The EVA M8M modules can be easily integrated in ...

Page 8: ... short routing matched impedance and no stubs External LNA With EVA M8M an additional external LNA is mandatory if a passive antenna is used to achieve the performance values as written in the EVA M8M Data Sheet 1 2 1 Power management 2 1 1 Overview The EVA M8M modules provide 4 supply pins VCC VCC_IO V_BCKP and V_USB They can be supplied independently or tied together to adapt various concepts de...

Page 9: ...a power failure at VCC_IO the backup domain is supplied by V_BCKP 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 voltage drop on the pin with possible malfunctions If the RTC frequency is derived from the main clock the V_BCKP pin also supplies the ...

Page 10: ...bled by default The TX Ready functionality can be enabled and configured by proper AT commands sent to the involved u blox cellular module supporting the feature For more information see the 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 A UART interface is available for se...

Page 11: ... not present The 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 changed In order to get the 90Ω differential impedance in between the USB_DM and USB_DP data line a 27Ω series resistor R1 R2 must be placed into each data line USB_DM and USB_DP Fig...

Page 12: ...um SQI Flash size of 8 Mbit An 8 Mbit device is also sufficient to save AssistNow Offline and AssistNow Autonomous information as well as Current configuration data However to run Firmware from the SQI Flash and provide space for logging results a minimum size of 8 Mbit might not be sufficient depending on the amount of data to be logged For more information about supported SQI Flash devices see T...

Page 13: ...all u blox M8 modules and for aiding Leave open if unused its function is disabled by default By default the external interrupt is disabled For further information see the u blox M8 Receiver Description Including Protocol Specification 2 If the EXTINT is configured for on off switching of the EVA M8M series the internal pull up becomes disabled Thus make sure the EXTINT input is always driven with...

Page 14: ...r if it s not required e g in Power Save Mode The status of the active antenna can be checked by the UBX MON HW message More information see the u blox M8 Receiver Description Including Protocol Specification 2 The open drain buffers U4 U7 and U8 e g Fairchild NC7WZ07 are needed to shift the voltage levels R3 is required as a passive pull up to control T1 because U4 has an open drain output R4 ser...

Page 15: ...ding the following sequence to the receiver B5 62 06 41 0C 00 00 00 03 1F 47 F2 D7 AD FF FF FC FF 2B 3D Applying this sequence results in a permanent change and cannot be reversed 2 4 3 RTC using an external clock Some applications can provide a suitable 32 768 kHz external reference to drive the EVA M8M RTC The external reference can simply be connected to the RTC_I pin Make sure that the 32 768 ...

Page 16: ...performance needed by the application in terms of Noise figure sensitivity Selectivity and linearity Robustness against jamming Robustness against RF power and ESD The external LNA U1 must be placed close to the passive antenna to get best performance The ANT_OFF pin can be used to turn off an external LNA The ANT_OFF signal must be inverted for common LNAs which come with an enable pin which has ...

Page 17: ... by the host to the EVA M8M in order to enable communication After sending the training sequence the host has to wait for at least 2 ms before sending messages to the EVA M8M receivers For further information see the u blox M8 Receiver Description Including Protocol Specification 2 Safe Boot Mode is used in production to program the SQI Flash It is recommended to have the possibility to pull the S...

Page 18: ...he EVA M8M series an external LNA is mandatory if no active antenna is used to achieve the performance values as written in the EVA M8M Data Sheet 1 Make sure the antenna is not placed close to noisy parts of the circuitry and not facing noisy parts e g micro controller display etc To optimize performance in environments with out band jamming interference sources use an additional SAW filter For m...

Page 19: ...2 I O Data line 2 to external SQI flash memory or reserved configuration pin Leave open if not used SQI_D1 I O Data line 1 to external SQI flash memory or reserved configuration pin Leave open if not used SQI_CS I O Chip select for external SQI flash memory or configuration enable pin Leave open if not used SQI_D3 I O Data line 3 to external SQI flash memory or reserved configuration pin Leave ope...

Page 20: ...ule etc Calculation of the micro 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 line is only GND as well as under the RF line In case of a multi layer PCB use the thickness of the dielectric between the signal and the 1st GND layer typically the 2nd lay...

Page 21: ... mask shall be 50 µm smaller than the copper pads with a paste thickness of 100 µm The paste mask outline needs to be considered when defining the minimal distance to the next component These are recommendations only and not specifications The exact geometry distances stencil thicknesses and solder paste volumes must be adapted to the specific production processes e g soldering etc of the customer...

Page 22: ...ash memory allows for the usage of data logging and increases AssistNow Offline and Autonomous performances More information and recommendations for using an external SQI flash see section 2 2 5 It is highly advisable that customers consider a design review with the u blox support team to ensure the compatibility of key functionalities For an overall description of the module software operation se...

Page 23: ...MOSI Configuration pin Leave open if not used RESERVED Leave open Different functions Only compatible if this pin is left open 15 MISO CFG_COM1 SPI MISO Configuration pin Leave open if not used RESERVED Leave open Different functions Only compatible if this pin is left open 16 CFG_GPS0 SCK Power Mode Configuration pin SPI Clock Leave open if not used RESERVED Leave open Different functions Only co...

Page 24: ...ESD is the sudden and momentary electric current that flows between two objects at different electrical potentials caused by direct contact or induced by an electrostatic field The term is usually used in the electronics and other industries to describe momentary unwanted currents that may cause damage to electronic equipment 2 13 2 ESD protection measures GNSS receivers are sensitive to Electrost...

Page 25: ... handheld type design an isolation of approximately 20 dB can be reached with careful placement of the antennas If such isolation can t be achieved e g in the case of an integrated GSM GNSS antenna an additional input filter is needed on the GNSS side to block the high energy emitted by the GSM transmitter Examples of these kinds of filters would be the SAW Filters from Epcos B9444 or B7839 or Mur...

Page 26: ...hat are different from the GNSS carrier see Figure 10 The main sources are wireless communication systems such as GSM CDMA WCDMA WiFi BT etc 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 Figure 10 Out band interference signals Measures against out ba...

Page 27: ...ed when 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 Unless there is a galvanic coupling between the local GND i e the work table and the PCB GND then the first point of contact when handling the PCB shall always be between the local GND and PCB GND Be...

Page 28: ...ly single reflow soldering processes are recommended for boards populated with EVA M8M modules 3 3 5 Wave soldering Base boards with combined through hole technology THT components and surface mount technology SMT devices require wave soldering to solder the THT components Only a single wave soldering process is encouraged for boards populated with EVA M8M 3 3 6 Rework Not recommended 3 3 7 Confor...

Page 29: ...nt Communications Positioning Technology www positioningtechnology co uk Figure 12 Multi GNSS generator 4 2 1 Guidelines for sensitivity tests 1 Connect a Multi GNSS generator to the OEM product 2 Choose the power level in a way that the Golden Device would report a C No ratio of 38 40 dBHz 3 Power up the DUT Device Under Test and allow enough time for the acquisition 4 Read the C N0 value from th...

Page 30: ...4006179 R02 Early Production Information Appendix Page 30 of 45 Appendix A Reference schematics A 1 Cost optimized circuit Passive Antenna No RTC crystal No backup battery UART and DDC for communication to host Figure 13 Cost optimized circuit ...

Page 31: ...al UBX 14006179 R02 Early Production Information Appendix Page 31 of 45 A 2 Best performance circuit with passive antenna External LNA RTC crystal Backup battery UART and DDC for communication to host Figure 14 Best performance circuit ...

Page 32: ...y Production Information Appendix Page 32 of 45 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 Figure 15 Standard circuit for an improved jamming immunity ...

Page 33: ...ual UBX 14006179 R02 Early Production Information Appendix Page 33 of 45 A 4 Circuit using active antenna Active antenna RTC crystal Backup battery UART and DDC for communication to host Figure 16 Standard circuit using active antenna ...

Page 34: ...14006179 R02 Early Production Information Appendix Page 34 of 45 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 17 USB self powered circuit ...

Page 35: ... UBX 14006179 R02 Early Production Information Appendix Page 35 of 45 A 6 USB bus powered circuit with passive antenna External LNA RTC crystal Backup battery SPI for communication to host USB interface Figure 18 USB bus powered circuit ...

Page 36: ...06179 R02 Early Production Information Appendix Page 36 of 45 A 7 Circuit using 2 pin antenna supervisor 2 pin antenna supervisor RTC crystal Backup battery UART and DDC for communication to host Figure 19 Circuit using 2 pin antenna supervisor ...

Page 37: ...06179 R02 Early Production Information Appendix Page 37 of 45 A 8 Circuit using 3 pin antenna supervisor 3 pin antenna supervisor RTC crystal Backup battery UART and DDC for communication to host Figure 20 Circuit using 3 pin antenna supervisor ...

Page 38: ...ariant 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 NEO 7 N M P EVA M8 M MAX M8 C W Q NEO M8 N M Q LEA M8 S PAM 7 Q CAM M8 Q integrated optimal performance Table 8 Combinations of u blox GNSS modules with different cellular technologies 2G 3G 4G See the GPS Implementation ...

Page 39: ...V T1A 32 768 kHz 7 0 pF 100 ppm Table 10 Recommend parts list for RTC crystal B 2 RF band pass filter F1 Depending on the application circuit consult manufacturer data sheet for DC ESD and RF power ratings Manufacturer Order No System supported Comments TDK EPCOS B8401 B39162B8401P810 GPS GLONASS High attenuation TDK EPCOS B3913 B39162B3913U410 GPS GLONASS BeiDou For automotive application TDK EPC...

Page 40: ...AFFB1G58KA0F0A GPS GLONASS High 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 Ceramic filter also offers robust ESD Protection TAI SAW TA1573A GPS GLONASS Low insertion loss TAI SAW TA1343A GPS GLONASS BeiDou Low insertion loss Table 12 Recommended part...

Page 41: ...2DW 1 8V 32Mbit several package temperature options Table 17 Recommend parts list for optional SQI Flash B 8 RF ESD protection diode D2 Manufacturer Order No ON Semiconductor ESD9R3 3ST5G Infineon ESD5V3U1U 02LS Table 18 Recommend parts list for RF ESD protection diode B 9 Operational amplifier U6 Manufacturer Order No Linear Technology LT6000 Linear Technology LT6003 Table 19 Recommend parts list...

Page 42: ...d parts list for inductor B 15Standard capacitors Name Use Type Value C0 RF input DC block COG 47P 5 25V C1 Decoupling Capacitor X7R 10N 10 16V C2 Decoupling capacitor at VBUS Depends on USB LDO U2 specification C3 Decoupling capacitor at VBUS Depends on USB LDO U2 specification C4 Decoupling VCC_IO at SQI Flash supply pin X5R 1U0 10 6 3V Table 25 Standard capacitors B 16Standard resistors Name Us...

Page 43: ...nterference EOS Electrical Overstress EPA Electrostatic Protective Area ESD Electrostatic discharge GLONASS Russian satellite system GND Ground GNSS Global Navigation Satellite System GPS Global Positioning System GSM Global System for Mobile Communications IEC International Electrotechnical Commission PCB Printed circuit board SBAS Satellite Based Augmentation System QZSS Quasi Zenith Satellite S...

Page 44: ... X 02007 5 GPS Implementation and Aiding Features in u blox wireless modules Docu No GSM G1 CS 09007 6 u blox 7 to u blox M8 Software Migration Guide Docu No UBX 13003254 For regular updates to u blox documentation and to receive product change notifications please register on our homepage Revision history Revision Date Name Status Comments R01 30 Sep 2014 julu ffel Advance Information R02 09 Dec ...

Page 45: ... Phone 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 Beijing Phone 86 10 68 133 545 E mail info_cn u blox com Support support_cn u blox com Regional Office China Shenzhen Phone 86 755 8627 1083 E mail info_cn u blox com Support support_cn u blox com R...

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