Ublox EVA-M8M Quick setup guide

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 standal
one 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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Document Information
Title EVA-M8M
Subtitle u-blox M8 concurrent GNSS modules
Document type Hardware Integration Manual
Document number UBX-14006179
Revision and date R02 09-Dec-2014
Document status Early Production Information
Document status explanation
Objective Specification Document contains target values. Revised and supplementary data will be published later.
Advance Information Document contains data based on early testing. Revised and supplementary data will be published later.
Early Production Information Document contains data from product verification. Revised and supplementary data may be published later.
Production Information Document contains the final product specification.
This document applies to the following products:
Product name Type number ROM/FLASH 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 any part thereof without the express permission of u-blox is strictly prohibited.
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. This document may be revised by u-blox at any time. For most recent documents, please visit
www.u-blox.com.
Copyright © 2014, u-blox AG
u-blox®is a registered trademark of u-blox Holding AG in the EU and other countries. ARM®is the registered trademark of ARM Limited in
the EU and other countries.

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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.
•GPS Compendium:This document, also known as the GPS book, provides a wealth of information
regarding generic questions about GPS system functionalities and technology.
•Receiver Description including Protocol Specification: This document describes messages, configuration
and functionalities of the EVA-M8M software releases and receivers.
•Hardware Integration Manuals: These manuals provide hardware design instructions and information on
how to set up production and final product tests.
•Application Notes: These documents provide general design instructions and information that applies to all
u-blox GNSS positioning modules.
How to use this Manual
This manual has a modular structure. It is not necessary to read it from beginning to end.
The following symbols 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 the questions and answers on our FAQ database on the homepage.
Technical Support
Worldwide Web
Our website (http://www.u-blox.com) is a rich pool of information. Product information, technical documents
and helpful FAQ can be accessed 24 h a day.
By E-mail
If you have technical problems or cannot find the required information in the provided documents, contact the
closest Technical Support office. To ensure that we process your request as soon as possible, use our service pool
email addresses rather than personal staff email addresses. Contact details are at the end of the document.
Helpful Information when Contacting Technical Support
When contacting Technical Support please have the following information ready:
•Receiver type (e.g. NEO-7N-0-000), Datacode (e.g. 172100.0100.000) and firmware version (e.g. ROM1.0)
•Receiver/module configuration
•Clear description of your question or the problem (may include a u-center logfile)
•A short description of the application
•Your complete contact details

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Contents
Preface ................................................................................................................................3
Contents..............................................................................................................................4
1Hardware description ..................................................................................................7
1.1 Overview .............................................................................................................................................. 7
2Design-in.......................................................................................................................8
2.1 Power management ............................................................................................................................. 8
2.1.1 Overview ....................................................................................................................................... 8
2.1.2 Power management configuration ................................................................................................ 9
2.2 Interfaces............................................................................................................................................ 10
2.2.1 UART interface ............................................................................................................................ 10
2.2.2 Display Data Channel (DDC) Interface ......................................................................................... 10
2.2.3 SPI Interface ................................................................................................................................ 11
2.2.4 USB interface............................................................................................................................... 11
2.2.5 SQI Flash memory........................................................................................................................ 12
2.3 I/O Pins ............................................................................................................................................... 13
2.3.1 Time 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 Mode (SAFEBOOT_N pin).................................................................................................... 17
2.7 RESET_N ............................................................................................................................................. 17
2.8 Design-in checklist.............................................................................................................................. 18
2.8.1 General considerations ................................................................................................................ 18
2.8.2 Schematic design-in for EVA-M8M.............................................................................................. 18
2.9 Pin description .................................................................................................................................... 19
2.10 Layout design-in checklist ............................................................................................................... 20
2.11 Layout............................................................................................................................................. 20
2.11.1 Footprint ..................................................................................................................................... 21
2.11.2 Paste mask .................................................................................................................................. 21

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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 Electrical Overstress (EOS)............................................................................................................ 24
2.13.4 EOS protection measures............................................................................................................. 25
2.13.5 Applications with cellular modules .............................................................................................. 25
3Product handling & soldering....................................................................................27
3.1 Packaging, shipping, storage and moisture preconditioning ............................................................... 27
3.2 ESD handling precautions ................................................................................................................... 27
3.3 Soldering ............................................................................................................................................ 27
3.3.1 Soldering paste............................................................................................................................ 27
3.3.2 Reflow soldering ......................................................................................................................... 28
3.3.3 Optical inspection........................................................................................................................ 28
3.3.4 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
4Product 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
AReference schematics.................................................................................................30
A.1 Cost optimized circuit ......................................................................................................................... 30
A.2 Best performance circuit with passive antenna.................................................................................... 31
A.3 Improved jamming immunity with passive antenna............................................................................. 32
A.4 Circuit using active antenna................................................................................................................ 33
A.5 USB self-powered circuit with passive antenna ................................................................................... 34
A.6 USB bus-powered circuit with passive antenna ................................................................................... 35
A.7 Circuit using 2-pin antenna supervisor ................................................................................................ 36
A.8 Circuit using 3-pin antenna supervisor ................................................................................................ 37
A.9 Design-in Recommendations in combination with cellular operation................................................... 38
BComponent selection .................................................................................................39
B.1 External RTC (Y1)................................................................................................................................ 39

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B.2 RF band-pass filter (F1) ....................................................................................................................... 39
B.3 External LNA protection filter (F2) ....................................................................................................... 40
B.4 USB line protection (D1) ..................................................................................................................... 40
B.5 USB LDO (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
CGlossary ......................................................................................................................43
Related documents...........................................................................................................44
Revision history................................................................................................................44
Contact..............................................................................................................................45

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1Hardware description
1.1 Overview
The EVA-M8M standalone concurrent GNSS modules feature the exceptional performance of the u-blox M8
positioning engine (GPS/QZSS, GLONASS, and BeiDou signals). The EVA-M8M series delivers high sensitivity and
minimal acquisition times in the ultra compact 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
separated.
The EVA-M8M series uses a crystal oscillator for lower system costs. Like other u-blox GNSS modules, the
EVA-M8M uses components selected for functioning reliably in the field over the full operating temperature
range.
With dual-frequency RF front-end, the u-blox M8 concurrent GNSS engine is able to intelligently use the highest
amount of visible satellites from two GNSS (GPS, GLONASS and BeiDou) systems 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 manufacturing, thanks to the QFN-like package and low
moisture sensitivity level. The modules are available in 500 pcs/reel, ideal for small production batches. The
EVA-M8M modules combine a high level of integration capability with flexible connectivity options in a miniature
package. This makes them perfectly suited for industrial and mass-market end products with strict size and cost
requirements. The DDC (I2C compliant) interface provides connectivity and enables synergies with u-blox cellular
modules.
The EVA-M8M modules are manufactured in ISO/TS 16949 certified sites and qualified as stipulated in the
JESD47 standard.
For applications needing firmware update capability or data logging, the EVA-M8M series must be
connected to an external SQI Flash memory. For more information about product features, see the
EVA-M8M Data Sheet [1].
To determine which u-blox product best meets your needs, see the product selector tables on the u-blox
website www.u-blox.com.

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2Design-in
In order to obtain good performance with a GNSS receiver module, there are a number of points that require
careful attention during the design-in. These include:
•Power Supply: Good performance requires a clean and stable power supply.
•Interfaces: Ensure correct wiring, rate and message setup on the module and your host system.
•Antenna interface: For optimal performance, seek 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, depending on the intended application. 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.
Figure 1: EVA-M8M power supply example

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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.
Do not add any series resistance (< 0.2 Ω) to the VCC supply, as it will generate input voltage noise due
to the dynamic current conditions.
2.1.1.2 I/O supply voltage (VCC_IO)
The digital I/Os of the EVA-M8M modules can be supplied with a separate voltage from the host system
connected to the VCC_IO pin of the module. The wide range of VCC_IO allows seamless interfacing to standard
logic voltage levels. However, in most applications VCC_IO and VCC share the same voltage level and are tied
together. VCC_IO supplies also the RTC and the backup RAM (BBR) during normal operation.
VCC_IO must be supplied in order for the system to boot.
When running the firmware from the external SQI Flash most of the VDD_IO current is consumed by the
SQI bus.
2.1.1.3 Backup power supply (V_BCKP)
In the event of 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 clock domain if
there is a power failure at VCC_IO, meaning that the V_BCKP current will also be higher. Ensure that
the capacity of the backup battery chosen meets your requirements.
2.1.1.4 USB interface power supply
V_USB supplies I/Os of the USB interface. If the USB interface is being used, the system can be either self-
powered, i.e. powered independently from the USB bus, or it can be bus-powered, i.e. powered through the
USB connection. In bus-powered mode, the system supply voltages need to be generated from the USB supply
voltage VBUS.
If the USB interface is not used, the V_USB pin must be connected to GND.
2.1.2 Power management configuration
Depending on the application, the power supply schematic will differ. Some examples are shown in the
following sections:
•Single supply voltage for VCC and VCC_IO, no backup supply see Appendix, Figure 13
•Separate supply voltages for VCC, VCC_IO and V_BCKP see Appendix, Figure 14
•Single supply voltage for VCC and VCC_IO, use of a backup supply see Appendix, Figure 16
For description of the different operating modes see the EVA-M8M Data Sheet [1].

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2.2 Interfaces
The EVA-M8M modules provide UART, SPI and DDC (I2C compatible) interfaces for communication with a host
CPU. A USB interface is also available on dedicated pins (see section 2.2.4). Additionally, an SQI interface is
available for connecting the EVA-M8M modules with an optional external flash memory.
The UART, SPI and DDC pins are supplied by VCC_IO and operate at this voltage level.
Four dedicated pins can be configured as either 1 x UART and 1 x DDC or a single SPI interface selectable by
D_SEL pin. Table 1 below provides the port mapping details.
Pin 32 (D_SEL) = “high” (left open) Pin 32 (D_SEL) = “Low” (connected to GND)
UART TX SPI MISO
UART RX SPI MOSI
DDC SCL SPI CLK
DDC SDA SPI CS
Table 1: Communication Interfaces overview
It is not possible to use the SPI interface simultaneously with the DDC or UART interface.
For debugging purposes, it is recommended to have a second interface e.g. USB available that is
independent from the application and accessible via test-points.
For each interface, a dedicated pin can be defined to indicate that data is ready to be transmitted. The TX Ready
signal indicates that the receiver has data to transmit. A listener can wait on the TX Ready signal instead of
polling the DDC or SPI interfaces. The UBX-CFG-PRT message lets you configure the polarity and the number of
bytes in the buffer before the TX Ready signal goes active. The TX Ready function is disabled 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 serial communication to a host CPU. The UART interface supports configurable
data rates with the default at 9600 baud. Signal levels are related to the VCC_IO supply voltage. An interface
based on RS232 standard levels (+/- 7 V) can be realized using level shifter ICs such as the Maxim MAX3232.
Hardware handshake signals and synchronous operation are not supported.
A signal change on the UART RX pin can also be used to wake up the receiver in Power Save Mode (see the
u-blox M8 Receiver Description Including Protocol Specification [2]).
2.2.2 Display Data Channel (DDC) Interface
An I2C compatible Display Data Channel (DDC) interface is available for serial communication with a host CPU.
The SCL and SDA pins have internal pull-up resistors sufficient for most applications. However, depending on the
speed of the host and the load on the DDC lines additional external pull-up resistors might be necessary. For
speed and clock frequency see the EVA-M8M Data Sheet [1].
To make use of DDC interface the D_SEL pin has to be left open.
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].