u-blox EVA-M8M Hardware Integration Manual

M8 concurrent gnss modules
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EVA-M8M
u-blox M8 concurrent GNSS modules
Hardware Integration Manual
Abstract
This document describes the hardware features and specifications of
the cost effective 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

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Summary of Contents for u-blox EVA-M8M

  • Page 1 This document describes the hardware features and specifications of the cost effective 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.
  • Page 2 The information contained herein is provided “as is” and u-blox assumes no liability for the use of the information. No warranty, either express or implied, is given, including but not limited, with respect to the accuracy, correctness, reliability and fitness for a particular purpose of the information.
  • Page 3: Preface

    Preface u-blox Technical Documentation As part of our commitment to customer support, u-blox maintains an extensive volume of technical documentation for our products. In addition to our product-specific technical data sheets, the following manuals are available to assist u-blox customers in product design and development.
  • Page 4: Table Of Contents

    Safe Boot Mode (SAFEBOOT_N pin) ....................17 RESET_N ............................. 17 Design-in checklist ..........................18 2.8.1 General considerations ........................ 18 2.8.2 Schematic design-in for EVA-M8M ....................18 Pin description ............................ 19 2.10 Layout design-in checklist ....................... 20 2.11 Layout ............................. 20 2.11.1...
  • Page 5 EVA-M8M - Hardware Integration Manual 2.11.3 Placement ........................... 22 2.12 Migration considerations ......................... 22 2.12.1 C88-M8M - Evaluating EVA-M8M on existing NEO-xM sockets ........... 22 2.13 EOS/ESD/EMI precautions ........................ 24 2.13.1 Electrostatic Discharge (ESD) ......................24 2.13.2 ESD protection measures ......................24 2.13.3...
  • Page 6 EVA-M8M - Hardware Integration Manual RF band-pass filter (F1) ........................39 External LNA protection filter (F2) ....................... 40 USB line protection (D1) ........................40 USB LDO (U2) ............................. 40 External LNA (U1) ..........................40 Optional SQI Flash (U3) ........................41 RF ESD protection diode (D2) ......................
  • Page 7: Hardware Description

    EVA form factor. The EVA-M8M series is an ideal solution for cost and space-sensitive applications. It is easy to design-in, only requiring an external GNSS antenna in most applications. The layout of the EVA-M8M modules is especially designed to ease the customer’s design and limit near field interferences since RF and digital domains are kept...
  • Page 8: Design-In

    The different supply voltages are explained in the following subsections. Figure 1 shows an example to supply the EVA-M8M modules when not using the USB interface. In this case, the V_USB pin is connected to ground.
  • Page 9: Power Management Configuration

    2.1.1.1 Main supply voltage (VCC) During operation, the EVA-M8M modules are supplied through the VCC pin. It makes use of an internal DC/DC converter for improved power efficiency. In a following step, built-in LDOs generate stabilized voltages for the Core and RF domains of the chip respectively. The current at VCC depends heavily on the current state of the system and is in general very dynamic.
  • Page 10: Interfaces

    The EVA-M8M DDC interface provides serial communication with u-blox cellular modules. See the specification of the applicable cellular module to confirm compatibility. For more information about DDC implementation refer to the u-blox M8 Receiver Description Including Protocol Specification [2]. UBX-14006179 - R02...
  • Page 11: Spi Interface

    To make use of the SPI interface, the D_SEL pin has to be connected to GND. 2.2.4 USB interface The USB interface of the EVA-M8M modules support the full-speed data rate of 12 Mbit/s. It is compatible to the USB 2.0 FS standard. The interface requires some external components in order to implement the physical characteristics required by the USB 2.0 specification.
  • Page 12: Sqi Flash Memory

    The VCC_IO monitor threshold (iomonCfg) must be set according to the SQI supply voltage level (VCC_IO). When using a 3.0 V or a 3.3 V flash memory device send one of the following sequences to the EVA-M8M receiver in production: B5 62 06 41 0C 00 00 00 03 1F 20 EC 68 C6 FE 7F FE FF 29 3E (for a 3.0 V Flash memory)
  • Page 13: I/O Pins

    EXTINT is an external interrupt pin with fixed input voltage thresholds with respect to VCC_IO (see the EVA-M8M Data Sheet [1] for more information). It can be used for wake-up functions in Power Save Mode on 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.
  • Page 14: Electromagnetic Interference On I/O Lines

    ANT_OFF (antenna on/off control) pins. This function must be activated by sending the following sequence to the EVA-M8M receivers in production: B5 62 06 41 0C 00 00 00 03 1F CD 1A 38 57 FF FF F6 FF DE 11 Applying this sequence results in a permanent change and cannot be reversed.
  • Page 15: Rtc Using A Crystal

    2.4.4 Time aiding Time can also be sent by UBX message at every startup of the EVA-M8M modules. This can be done to enable warm starts, AssistNow Autonomous and AssistNow Offline. This can be done when no RTC is maintained.
  • Page 16: Rf Input

    2.5.1 Active Antenna In case an active antenna is used, just the active antenna supply circuit has to be added in front of the EVA-M8M modules RF-input, see Figure 16. In case the active antenna has to be supervised, either the 2-pin active antenna supervisor circuit (see Figure 19) or the 3-pin active antenna supervisor circuit (see Figure 20), has to be added to the active antenna circuit.
  • Page 17: Safe Boot Mode (Safeboot_N Pin)

    Safe Boot Mode (SAFEBOOT_N pin) If the SAFEBOOT_N pin is “low” at start up, the EVA-M8M series starts in Safe Boot Mode and doesn’t begin GNSS operation. In Safe Boot Mode the EVA-M8M series runs from an internal LC oscillator and starts regardless of any configuration provided by the configuration pins.
  • Page 18: Design-In Checklist

    The total noise figure including external LNA (or the LNA in the active antenna) should be around 1 dB.  With the 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].
  • Page 19: Pin Description

    EVA-M8M - Hardware Integration Manual Pin description Name Description Remark ANT_OFF Antenna control Leave open if not used. ANT_OK Antenna status Leave open if not used. D_SEL Interface selector See section 2.2. Ground Outer ground pin Ground Outer ground pin...
  • Page 20: Layout Design-In Checklist

    Is the grounding concept optimal?  Has the 50 Ohm line from antenna to EVA-M8M (micro strip / coplanar waveguide) been kept as short as possible? Assure low serial resistance in VCC power supply line (choose a line width > 400 um).
  • Page 21: Footprint

    EVA-M8M - Hardware Integration Manual 2.11.1 Footprint Pin36 Pin1 Figure 5: Recommended footprint (bottom view) Units are in mm. 2.11.2 Paste mask The paste mask shall be 50 µm smaller than the copper pads with a paste thickness of 100 µm.
  • Page 22: Placement

    2.12 Migration considerations EVA-M8M series is the successor of the EVA-7M. u-blox is committed to ensuring that products in the same form factor are backwards compatible over several technology generations. Utmost care has been taken to ensure there is no negative impact on function or performance and to make u-blox M8 modules as fully compatible as possible with u-blox 7 versions.
  • Page 23 RF_IN GPS signal input RF_IN GPS signal input to achieve the performance values shown in the EVA-M8M Data Sheet [1]. The Noise Figure of the C88-M8M is about 2 dB higher than NEO- No difference No difference MOSI/ SPI MOSI / Configuration Different functions.
  • Page 24: Eos/Esd/Emi Precautions

    To prevent overstress damage at the RF_IN of your receiver, never exceed the maximum input power as specified in the EVA-M8M Data Sheet [1]. 2.13.1 Electrostatic Discharge (ESD) Electrostatic discharge (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.
  • Page 25: Eos Protection Measures

    GSM uses power levels up to 2W (+33dBm). Make sure that absolute maximum input power level of the GNSS receiver is not exceeded. See the GPS Implementation and Aiding Features in u-blox wireless modules [5]. 2.13.5.1 Isolation between GNSS and GSM antenna In a handheld type design, an isolation of approximately 20 dB can be reached with careful placement of the antennas.
  • Page 26 EVA-M8M - Hardware Integration Manual 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...
  • Page 27: Product Handling & Soldering

    Packaging, shipping, storage and moisture preconditioning For information pertaining to reels and tapes, Moisture Sensitivity levels (MSD), shipment and storage information, as well as drying for preconditioning see the EVA-M8M Data Sheet [1] . ESD handling precautions ESD prevention is based on establishing an Electrostatic Protective Area (EPA). The EPA can be a small working station or a large manufacturing area.
  • Page 28: Reflow Soldering

    Casting will void the warranty. 3.3.9 Use of ultrasonic processes Some components on the EVA-M8M modules are sensitive to Ultrasonic Waves. Use of any Ultrasonic Processes (cleaning, welding etc.) may cause damage to the GNSS Receiver. u-blox offers no warranty against damages to the EVA-M8M modules caused by any Ultrasonic Processes.
  • Page 29: Product Testing

    4 Product testing Test parameters for OEM manufacturer Because of the testing done by u-blox, it is obvious that an OEM manufacturer doesn’t need to repeat firmware tests or measurements of the GNSS parameters/characteristics (e.g. TTFF) in their production test.
  • Page 30: Appendix

    EVA-M8M - Hardware Integration Manual 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 UBX-14006179 - R02...
  • Page 31: Best Performance Circuit With Passive Antenna

    EVA-M8M - Hardware Integration Manual 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 UBX-14006179 - R02 Early Production Information...
  • Page 32: Improved Jamming Immunity With Passive Antenna

    EVA-M8M - Hardware Integration Manual 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: Circuit Using Active Antenna

    EVA-M8M - Hardware Integration Manual 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 UBX-14006179 - R02 Early Production Information...
  • Page 34: Usb Self-Powered Circuit With Passive Antenna

    EVA-M8M - Hardware Integration Manual 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 UBX-14006179 - R02...
  • Page 35: Usb Bus-Powered Circuit With Passive Antenna

    EVA-M8M - Hardware Integration Manual 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 UBX-14006179 - R02 Early Production Information...
  • Page 36: Circuit Using 2-Pin Antenna Supervisor

    EVA-M8M - Hardware Integration Manual 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 UBX-14006179 - R02 Early Production Information...
  • Page 37: Circuit Using 3-Pin Antenna Supervisor

    EVA-M8M - Hardware Integration Manual 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 UBX-14006179 - R02 Early Production Information...
  • Page 38: Design-In Recommendations In Combination With Cellular Operation

      = integrated  = optimal performance • Table 8: Combinations of u-blox GNSS modules with different cellular technologies (2G/3G/4G) See the GPS Implementation and Aiding Features in u-blox wireless modules [5]. UBX-14006179 - R02 Early Production Information Appendix...
  • Page 39: B Component Selection

    EVA-M8M - Hardware Integration Manual B Component selection This section provides information about components that are critical for the performance of the EVA-M8M GNSS receiver module. Recommended parts are selected on a data sheet basis only. Temperature range specifications need only be as wide as required by a particular application. For the purpose of this document, specifications for industrial temperature range (-40 C …...
  • Page 40: External Lna Protection Filter (F2)

    EVA-M8M - Hardware Integration Manual B.3 External LNA protection filter (F2) 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: B39162-B8401-P810 GPS+GLONASS High attenuation...
  • Page 41: Optional Sqi Flash (U3)

    EVA-M8M - Hardware Integration Manual B.7 Optional SQI Flash (U3) Manufacturer Order No. Comments Macronix MX25U8035E 1.8V, 8Mbit, several package/temperature options Macronix MX25U1635E 1.8V, 16Mbit, several package/temperature options Macronix MX25L3239E 3V, 32Mbit, several package/temperature options Spansion S25FL116K 3V, 16Mbit, several package/temperature options...
  • Page 42: Feed-Thru Capacitors

    EVA-M8M - Hardware Integration Manual B.13 Feed-thru capacitors Manufacturer Order No. Comments MuRata NFL18SP157X1A3 For data signals, 34 pF load capacitance MuRata NFA18SL307V1A45 For data signals, 4 circuits in 1 package MuRata NFM18PC474R0J3 For power supply < 2 A, size 0603...
  • Page 43: Appendix

    EVA-M8M - Hardware Integration Manual Appendix C Glossary Abbreviation Definition ANSI American National Standards Institute BeiDou Chinese satellite navigation system CDMA Code Division Multiple Access Electromagnetic interference Electrical Overstress Electrostatic Protective Area Electrostatic discharge GLONASS Russian satellite system Ground GNSS...
  • Page 44: Related Documents

    GPS Implementation and Aiding Features in u-blox wireless modules, Docu. No. GSM.G1-CS-09007 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.
  • Page 45: Contact

    EVA-M8M - Hardware Integration Manual Contact For complete contact information, visit us at www.u-blox.com u-blox Offices North, Central and South America Headquarters Asia, Australia, Pacific Europe, Middle East, Africa u-blox America, Inc. u-blox Singapore Pte. Ltd. u-blox AG Phone: +1 703 483 3180...

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