u-blox EVA-8M Series, EVA-M8Q, EVA-8M, EVA-M8 Series, EVA-M8M Hardware Integration Manual

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EVA-8M and EVA-M8 series

u-blox 8 / u-blox M8 GNSS SiP modules

Hardware Integration Manual

Abstract

This document describes the hardware features and specifications of u-blox EVA-8M and EVA-

fully tested standalone solution that requires no host integration. The EVA-8M and EVA-M8

communication options.

www.u-blox.com

UBX-16010593 - R06

EVA-8M and EVA-M8 series - Hardware Integration Manual

u-blox or third parties may hold intellectual property rights in the products, names, logos and designs included in this document. Copying, reproduction, modification or disclosure to third parties permitted with the express written permission of u The information contained herein is provided “as is” and u implied, is given, includ purpose of the information. This document may be revised by u documents, visit www.u Copyright © u

Document Information

Title EVA-8M and EVA-M8 series

Subtitle u-blox 8 / u-blox M8 GNSS SiP modules

Document type Hardware Integration Manual

Document number UBX-16010593

Revision and date R06 7-Feb-2019

Document status Early Production Information

Product status

In Development / Prototype

Engineering Sample Advance Information Data based on early testing. Revised and supplementary data will be published later.

Initial Production Early Production Information Data from product verification. Revised and supplementary data may be published later.

Mass Production / End of Life

Corresponding content status

Objective Specification Target values. Revised and supplementary data will be published later.

Production Information Document contains the final product specification.

European Union regulatory compliance

EVA-8M, EVA-M8M, and EVA-M8Q comply with all relevant requirements for RED 2014/53/EU. The EVA-8M and EVA-M8M/Q Declaration of Conformity (DoC) is available at www.u-blox.com within Support > Product resources > Conformity Declaration.

This document applies to the following products:

Product name Type number ROM/FLASH version PCN reference

EVA-M8M EVA-M8M-0-10 ROM SPG 3.01 / Flash FW SPG 3.01 UBX-16012546

EVA-M8M EVA-M8M-1-10 ROM SPG 3.01 / Flash FW SPG 3.01 UBX-16012546 EVA-M8Q EVA-M8Q-0-10 ROM SPG 3.01 / Flash FW SPG 3.01 N/A

EVA-8M EVA-8M-0-10 ROM SPG 3.01 N/A

UBX-16010593 - R06 Page 2 of 47 Early Production Information

-blox AG.

ing but not limited to, with respect to the accuracy, correctness, reliability and fitness for a particular

-blox.com.

-blox.

-blox assumes no liability for its use. No warranty, either express or

-blox at any time without notice. For the most recent

of this document or any part thereof is only

EVA-8M and EVA-M8 series - Hardware Integration Manual

Document Information ................................................................................................................................ 2

Contents .......................................................................................................................................................... 3

1 Hardware description ........................................................................................................................... 6

1.1 Overview ........................................................................................................................................................ 6

2 Design-in ................................................................................................................................................... 7

2.1 Power management ................................................................................................................................... 7

2.1.1 Overview ............................................................................................................................................... 7

2.1.2 Power management configuration ................................................................................................. 8

2.2 Interfaces ...................................................................................................................................................... 9

2.2.1 UART interface .................................................................................................................................... 9

2.2.2 Display Data Channel (DDC) Interface ......................................................................................... 10

2.2.3 SPI Interface ...................................................................................................................................... 10

2.2.4 USB interface ..................................................................................................................................... 10

2.2.5 SQI Flash memory ............................................................................................................................. 11

2.3 I/O Pins ........................................................................................................................................................ 12

2.3.1 Time pulse .......................................................................................................................................... 12

2.3.2 External interrupt ............................................................................................................................. 13

2.3.3 Active antenna supervisor .............................................................................................................. 13

2.3.4 Electromagnetic interference and I/O lines ................................................................................. 14

2.4 Real-Time Clock (RTC) ............................................................................................................................. 15

2.4.1 RTC using a crystal ........................................................................................................................... 15

2.4.2 RTC derived from the system clock: “single crystal” feature .................................................. 15

2.4.3 RTC using an external clock ........................................................................................................... 15

2.4.4 Time aiding ......................................................................................................................................... 16

2.5 RF input ....................................................................................................................................................... 16

2.5.1 Active Antenna .................................................................................................................................. 16

2.5.2 Passive Antenna ............................................................................................................................... 16

2.5.3 Improved Jamming Immunity ........................................................................................................ 17

2.6 Safe Boot Mode (SAFEBOOT_N) ........................................................................................................... 17

2.7 System Reset (RESET_N) ....................................................................................................................... 18

2.8 Design-in checklist .................................................................................................................................... 18

2.8.1 General considerations .................................................................................................................... 18

2.8.2 Schematic design-in for EVA-8M / EVA-M8 series GNSS modules ....................................... 18

2.9 Pin description ........................................................................................................................................... 19

2.9.1 Pin name changes............................................................................................................................. 20

2.10 Layout design-in checklist ...................................................................................................................... 20

2.11 Layout .......................................................................................................................................................... 21

2.11.1 Footprint ............................................................................................................................................. 21

2.11.2 Paste mask ........................................................................................................................................ 21

2.11.3 Placement .......................................................................................................................................... 22

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2.12 Migration considerations ........................................................................................................................ 22

2.12.1 Hardware migration from EVA-7M to EVA-8M / EVA-M8M / EVA-M8Q .............................. 22

2.12.2 C88-M8M - Evaluating EVA-M8M on existing NEO-xM sockets ............................................ 24

2.13 EOS/ESD/EMI precautions ...................................................................................................................... 25

2.13.1 Electrostatic Discharge (ESD) ....................................................................................................... 26

2.13.2 ESD protection measures ............................................................................................................... 26

2.13.3 Electrical Overstress (EOS) ............................................................................................................ 26

2.13.4 EOS protection measures ............................................................................................................... 26

2.13.5 Electromagnetic interference (EMI) ............................................................................................. 27

2.13.6 Applications with cellular modules ............................................................................................... 27

3 Product handling & soldering .......................................................................................................... 30

3.1 Packaging, shipping, storage and moisture preconditioning .......................................................... 30

3.2 ESD handling precautions ....................................................................................................................... 30

3.3 Soldering ..................................................................................................................................................... 30

3.3.1 Soldering paste ................................................................................................................................. 30

3.3.2 Reflow soldering ................................................................................................................................ 31

3.3.3 Optical inspection ............................................................................................................................. 31

3.3.4 Repeated reflow soldering .............................................................................................................. 31

3.3.5 Wave soldering .................................................................................................................................. 31

3.3.6 Rework ................................................................................................................................................ 31

3.3.7 Use of ultrasonic processes ........................................................................................................... 31

4 Product testing ................................................................................................................................... 32

4.1 Test parameters for OEM manufacturer ............................................................................................. 32

4.2 System sensitivity test ............................................................................................................................ 32

4.2.1 Guidelines for sensitivity tests ...................................................................................................... 32

4.2.2 ‘Go/No go’ tests for integrated devices ........................................................................................ 32

Appendix ....................................................................................................................................................... 33

A Reference schematics ....................................................................................................................... 33

A.1 Cost optimized circuit .............................................................................................................................. 33

A.2 Best performance circuit with passive antenna ................................................................................. 34

A.3 Improved jamming immunity with passive antenna ......................................................................... 35

A.4 Circuit using active antenna ................................................................................................................... 36

A.5 USB self-powered circuit with passive antenna ................................................................................. 37

A.6 USB bus-powered circuit with passive antenna ................................................................................. 38

A.7 Circuit using 2-pin antenna supervisor ................................................................................................ 39

A.8 Circuit using 3-pin antenna supervisor ................................................................................................ 40

B Component selection ........................................................................................................................ 41

B.1 External RTC (Y1) ...................................................................................................................................... 41

B.2 RF band-pass filter (F1) ........................................................................................................................... 41

B.3 External LNA protection filter (F2) ........................................................................................................ 42

B.4 USB line protection (D2) .......................................................................................................................... 42

B.5 USB LDO (U1) ............................................................................................................................................. 42

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B.6 External LNA (U1) ..................................................................................................................................... 42

B.7 Optional SQI Flash (U3) ............................................................................................................................ 43

B.8 RF ESD protection diode (D2) ................................................................................................................. 43

B.9 Operational amplifier (U6) ....................................................................................................................... 43

B.10 Open-drain buffer (U4, U7 and U8) ........................................................................................................ 43

B.11 Antenna supervisor switch transistor (T1) ......................................................................................... 44

B.12 Ferrite beads (FB1) ................................................................................................................................... 44

B.13 Feed-thru capacitors ................................................................................................................................ 44

B.14 Inductor (L1) ............................................................................................................................................... 44

B.15 Standard capacitors ................................................................................................................................. 44

B.16 Standard resistors .................................................................................................................................... 45

C Glossary ................................................................................................................................................. 45

Related documents ................................................................................................................................... 46

Revision history .......................................................................................................................................... 46

Contact .......................................................................................................................................................... 47

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1 Hardware description

1.1 Overview

The EVA-8M / EVA-M8 series GNSS modules feature the excellent performance of the u-blox 8 / ublox M8 positioning engine. The EVA-8M / EVA-M8 series delivers high sensitivity and minimal acquisition times in the ultra-compact EVA form factor.

The EVA-8M / EVA-M8 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-8M / EVA-M8 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-8M and EVA-M8M series module uses a crystal oscillator for lower system costs, while EVAM8Q with TCXO provides best performance. Like other u-blox GNSS modules, the EVA series uses components selected for functioning reliably in the field over the full operating temperature range.

The EVA-M8M and EVA-M8Q modules include a dual-frequency RF front-end, with which the u-blox M8 concurrent GNSS engine is able to intelligently use the highest amount of visible satellites from up to three GNSS (GPS/Galileo, together with GLONASS or 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-8M includes a single-frequency RF front-end, and can receive and track either GPS or GLONASS signals.

The EVA-8M and EVA-M8 series 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-8M and EVA-M8 series 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-8M and EVA-M8 series modules are qualified as stipulated in the JESD47 standard.

☞ For applications needing data logging capability, storing configurations and hold AssistNow data,

the EVA-8M / EVA-M8 series GNSS modules must be connected to an external SQI Flash memory. Firmware update form SQI Flash memory is only supported with EVA-M8M and EVA-M8Q series GNSS modules. For more information about product features, see the the

EVA-8M Data Sheet

[2]

EVA-M8 Data Sheet

[1] and

☞ 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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2 Design-in

In order to obtain good performance with EVA-8M / EVA-M8 series GNSS receiver modules, there are a number of issues requiring 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-M8 and EVA-M8M modules, an additional external LNA is mandatory if a

passive antenna is used. With EVA-M8Q module, an additional external LNA is recommended with passive antenna.

2.1 Power management

2.1.1 Overview

The EVA-8M / EVA-M8 series GNSS modules provide four supply pins: VCC, VCC_IO, V_BCKP and VDD_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-8M / EVA-M8 series modules when not using the USB interface. In this case, the VDD_USB pin is connected to ground.

Figure 1: EVA-8M / EVA-M8 series power supply example

2.1.1.1 Main supply voltage (VCC)

During operation, the EVA-8M / EVA-M8 series GNSS 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

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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.

☞ The equipment must be supplied by an external limited power source in compliance with the clause

2.5 of the standard IEC 60950-1.

2.1.1.2 I/O supply voltage (VCC_IO)

The digital I/Os of the EVA-8M / EVA-M8 series GNSS 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.

The EVA-8M / EVA-M8 series GNSS modules come in two different IO voltage range flavors:

1. EVA-M8Q with IO voltage from 2.7 V to 3.6 V

2. EVA-M8M and EVA-8M with the wider range from 1.65 V to 3.6 V. The level should be set according to section 2.2.5.

☞ VCC_IO must be supplied in order for the system to boot. ☞ When running the firmware from the external SQI Flash most of the VCC_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 “single crystal” feature is enabled (which derives the RTC frequency 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. EVA-M8Q module uses TCXO oscillator and does not support the “single crystal” feature. For more information about “single crystal” feature see section 2.4.2

2.1.1.4 USB interface power supply

VDD_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 VDD_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

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☞ For description of the different power operating modes see the

EVA-8M Data Sheet

[2].

EVA-M8 Data Sheet

[1] and the

2.2 Interfaces

The EVA-8M / EVA-M8 series GNSS 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-8M / EVA-M8 series GNSS

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 TXD SPI MISO

UART RXD SPI MOSI

DDC SCL SPI CLK

DDC SDA SPI CS_N

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 TXD Ready signal indicates that the receiver has data to transmit. Each TXD Ready signal is associated with a particular interface and cannot be shared. A listener can wait on the TXD 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 TXD Ready signal goes active. The TXD Ready function is disabled by default.

☞ The TXD 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

Implementation and Aiding Features in u-blox wireless modules

[6].

GPS

☞ The TXD Ready feature is supported on several u-blox cellular module products.

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 RXD pin can also be used to wake up the receiver in Power Save Mode (see the

u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification

[3]).

☞ Designs must allow access to the UART and the SAFEBOOT_N pin for future service, updates, and

reconfiguration.

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Module

VDD

_USB

LDO

VDD_USB

USB_DP

USB

_DM

C24 C23

VBUS

GND

USB Device Connector

R11

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 the

EVA-8M Data Sheet

[2].

EVA-M8 Data Sheet

[1] and

☞ To make use of DDC interface the D_SEL pin has to be left open. ☞ The EVA-8M / EVA-M8 series GNSS modules DDC interface provides serial communication with

u-blox cellular modules. See the specification of the applicable cellular module to confirm compatibility.

2.2.3 SPI Interface

The SPI interface can be used to provide a serial communication with a host CPU. If the SPI interface is used, UART and DDC are deactivated, because they share the same pins.

☞ 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-8M / EVA-M8 series GNSS 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. Figure 2 shows the interface pins and additional external components. In order to comply with USB specifications, VBUS must be connected through a LDO (U1) to pin VDD_USB of the module. This ensures that the internal 1.5 shuts down VBUS.

Depending on the characteristics of the LDO (U1), for a self-powered design it is recommended to add a pull-down resistor (R8) at its output to ensure VDD_USB does not float if a USB cable is not connected, i.e. when VBUS is not present. In USB self-powered mode, the power supply (VCC) can be turned off and the digital block is not powered. In this case, since VBUS is still available, the USB host would still receive the signal indicating that the device is present and ready to communicate. This should be avoided by disabling the LDO (U1) using the enable signal (EN) of the VCC-LDO or the output of a voltage supervisor.

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 90

Ω differential impedance in between the USB_DM and USB_DP data line, a 27 Ω

series resistor (R4, R5) must be placed into each data line (USB_DM and USB_DP).

kΩ pull-up resistor on USB_DP gets disconnected when the USB host

Figure 2: USB interface

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Name Component Function Comments

U1 LDO Regulates VBUS (4.4 …5.25

V) down to a voltage of 3.3 V).

C24,C23 Capacitors Required according to the specification of LDO U1

D2 Protection

diodes

R4, R5 Serial

termination resistors

R11 Resistor Ensures defined signal at

Table 2: Summary of USB external components

Protect circuit from overvoltage / ESD when connecting.

Establish a full-speed driver impedance of 28…44 Ω

VDD_USB when VBUS is not connected / powered

Almost no current requirement (~1 mA) if the GNSS receiver is operated as a USB self-powered device, but if bus-powered LDO (U1) must be able to deliver the maximum current of ~100 mA.

Use low capacitance ESD protection such as ST Microelectronics USBLC6-2.

A value of 27 Ω is recommended.

100 kΩ is recommended for USB self-powered setup. For bus-powered setup R8 is not required.

See Appendix A.5 and Appendix A.6 for reference schematics for self- and bus-powered operation.

☞ If the USB interface is not used, connect VDD_USB to GND.

2.2.5 SQI Flash memory

An external SQI (Serial Quad Interface) Flash memory can be connected to the EVA-8M / EVA-M8 series GNSS modules. The SQI interface provides the following options:

• Store the current configuration permanently

• Save data logging results

• Hold AssistNow Offline and AssistNow Autonomous data

☞ In addition, the EVA-M8M and EVA-M8Q GNSS modules can make use of a dedicated flash

firmware with an external SQI Flash memory. The flash memory with these modules can be used to run firmware out of flash and to update the firmware as well. Running the firmware from the SQI Flash requires a minimum SQI Flash size of 8 Mbit.

☞ The voltage level of the SQI interface follows the VCC_IO level. Therefore, the SQI Flash must be

supplied with the same voltage as VCC_IO of the EVA-8M / EVA-M8 module. It is recommended to place a decoupling capacitor (C4) close to the supply pin of the SQI Flash.

☞ Make sure that the SQI Flash supply range matches the voltage supplied at VCC_IO.

Figure 3 : Connecting an external SQI Flash memory

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SQI Flash size of 8 Mbit is sufficient to save AssistNow Offline and AssistNow Autonomous information as well as current configuration data. However, for EVA-M8M and EVA-M8Q to run Firmware from the SQI Flash and provide space for logging results, a minimum size of 8 Mbit may not be sufficient depending on the amount of data to be logged.

☞ For more information about supported SQI Flash devices see Table 18.

EVA-8M / EVA-M8 series modules have a configurable VCC_IO monitor threshold (iomonCfg) to ensure that the module only start if the VCC_IO supply is within the supply range of the SQI Flash device (VCC_IO is used to supply the SQI Flash). This will ensure that any connected SQI Flash memory will be detected correctly at startup.

See the iomonCfg value.

With EVA-8M and EVA-M8M modules the VCC_IO monitor threshold is set to default 1.54 V value for using a 1.8 V Flash memory device.

With EVA-M8Q module, the VCC_IO monitor threshold is set to default 2.69 V value in production, but may be increased to 3.0 V.

If the default value for the VCC_IO monitor threshold is not suitable it can be set according to the IO supply voltage level (VCC_IO) in the eFuse by the Low Level Configuration.

If VCC_IO voltage 2.7 V to 3.0 V is used, send the following sequence to the module

• B5 62 06 41 0C 00 00 00 03 1F 04 BA CF 67 FF 7F FF FF E5 95

If VCC_IO voltage 3.0 V to 3.6 V is used, send the following sequence to the module

• B5 62 06 41 0C 00 00 00 03 1F 4F 22 4C 5C FF 7F 7F FF 8A 7C

u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification

[3] for setting the

☞ Applying these sequences result in a permanent change and cannot be reversed. An unstable

supply voltage at the VCC_IO pin while applying these sequences can also damage the receiver.

☞ Make sure that the SAFEBOOT_N pin is available for entering Safe Boot Mode. Programming the

SQI Flash memory with a Flash firmware is done typically at production. For this purpose the EVAM8M and EVA-M8Q GNSS modules have to enter the Safe Boot Mode. More information about SAFEBOOT_N pin see section 2.6.

☞ When the EVA-M8M-1 variant is attached with an external SQI flash without running a Flash

firmware, the default concurrent reception of GPS/QZSS/SBAS and BeiDou remains unchanged. In case the Flash is also used for execution of firmware update, the default reception will be reset to GPS/QZSS/SBAS and GLONASS. EVA-M8M-1 can be changed back to concurrent GPS/QZSS/SBAS and BeiDou by sending a dedicated UBX message (UBX-CFG-GNSS) to the module. More information see the

Specification

[3].

u-blox 8 / ublox M8 Receiver Description Including Protocol

2.3 I/O Pins

All I/O pins make use of internal pull-ups. Thus, there is no need to connect unused pins to VCC_IO.

2.3.1 Time pulse

A configurable time pulse signal is available with the EVA-8M / EVA-M8 series GNSS modules.

The TIMEPULSE output generates pulse trains synchronized with GPS or UTC time grid with intervals configurable over a wide frequency range. Thus it may be used as a low frequency time synchronization pulse or as a high frequency reference signal.

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By default, the time pulse signal is disabled. For more information, see the

Receiver Description Including Protocol Specification

[3].

u-blox 8 / u-blox M8

2.3.2 External interrupt

EXTINT is an external interrupt pin with fixed input voltage thresholds with respect to VCC_IO (see

the

EVA-M8 Data Sheet

[1] and the

EVA-8M Data Sheet

[2] 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.

If the EXTINT is not used for an external interrupt function, it can be used for some other purpose. E.g. as an output pin for the TXD Ready feature to indicate that the receiver has data to transmit.

For further information, see the pin assignment in section 2.9 and the u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification [3].

☞ If the EXTINT is configured for on/off switching of the EVA-8M / EVA-M8 series GNSS modules,

the internal pull-up becomes disabled. Thus make sure the EXTINT input is always driven within the defined voltage level by the host.

2.3.3 Active antenna supervisor

The EVA-8M / EVA-M8 series GNSS modules support active antenna supervisors. The antenna supervisor gives information about the status of the active antenna and will turn off the supply to the active antenna in case a short is detected or to optimize the power consumption when in Power Save Mode.

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 default, consists of the ANT_OK input and the ANT_OFF output pins.

Function I/O Description Remarks

ANT_OK I Antenna OK

“high” = Antenna OK “low” = Antenna not OK

ANT_OFF O Control signal to turn on and off the antenna supply

“high” = Antenna OFF “low” = Antenna ON

Table 3: 2-pin antenna supervisor pins

The circuitry, as shown in Appendix A.7 (see Figure 19) provides antenna supply short circuit detection. It will prevent antenna operation via transistor T1 if a short circuit has been detected or if it is not required (e.g. in Power Save Mode).

The status of the active antenna can be checked by the UBX-MON-HW message. For more information, see the

u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification

Open drain buffers U4 and U7 (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 serves as a current limiter in the event of a short circuit.

Default configuration

[3].

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2.3.3.2 3-pin antenna supervisor

The 3-pin antenna supervisor is comprised of the ANT_DET (active antenna detection), ANT_OK (short detection) and ANT_OFF (antenna on/off control) pins. This function must be activated by sending the following sequence to the EVA-8M / EVA-M8 series 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. An unstable supply

voltage at the VCC_IO pin while applying this sequence can also damage the receiver.

Function I/O Description Remarks

ANT_DET I

(pull-up)

ANT_OK I

(pull-up)

ANT_OFF O Control signal to turn on and off the antenna

Table 4: 3-pin Antenna supervisor pins

Antenna detected “high” = Antenna detected “low” = Antenna not detected

Antenna not shorted “high” = antenna has no short “low” = antenna has a short

supply “high” = turn off antenna supply “low” = short to GND

Byte sequence given in section 2.3.3.2 should be applied.

The external circuitry, as shown in Appendix A.8, (see Figure 20) provides detection of an active antenna connection status. If the active antenna is present, the DC supply current exceeds a preset threshold defined by R4, R5, and R6. It will shut down the antenna via transistor T1 if a short circuit has been detected via U7 or 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 8 / u-blox M8 Receiver Description Including Protocol Specification

[3].

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 serves as a current limiter in the event of a short circuit.

2.3.4 Electromagnetic interference and I/O lines

Any I/O signal line (length > ~3 mm) can act as an antenna and may pick up arbitrary RF signals transferring them as noise into the GNSS receiver. This specifically applies to unshielded lines, lines where the corresponding GND layer is remote or missing entirely, and lines close to the edges of the printed circuit board. If for example, a cellular signal radiates into an unshielded high-impedance line, it is possible to generate noise in the order of volts and not only distort receiver operation but also damage it permanently.

On the other hand, noise generated at the I/O pins will emit from unshielded I/O lines. Receiver performance may be degraded when this noise is coupled into the GNSS antenna (see Figure 9).

In case of improper shielding, it is recommended to use resistors or ferrite beads (see Appendix B.12) on the I/O lines in series. These components should be chosen with care because they will affect also the signal rise times. Alternatively, feed-thru capacitors with good GND connection close to the GNSS receiver can be used (see Appendix B.13).

EMI protection measures are particularly useful when RF emitting devices are placed next to the GNSS receiver and/or to minimize the risk of EMI degradation due to self-jamming. An adequate layout with a robust grounding concept is essential in order to protect against EMI. More information can be found in subsection 2.13.6.3.

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2.4 Real-Time Clock (RTC)

The use of the RTC is optional to maintain time in the event of power failure at VCC_IO. The RTC is required for hot start, warm start, AssistNow Autonomous, AssistNow Offline and in some Power Save Mode operations. The time information can either be generated by connecting an external RTC crystal to the module, by deriving the RTC from the internal crystal oscillator, by connecting an external 32.768 kHz signal to the RTC input, or by time aiding of the GNSS receiver at every startup.

If a power save mode is used then an external RTC crystal must be connected. Optionally the RTC frequency can be derived from the system clock or an external 32.768 kHz signal can be provided.

2.4.1 RTC using a crystal

The easiest way to provide time information to the receiver is to connect an RTC crystal to the corresponding pins of the RTC oscillator, RTC_I and RTC_O. There is no need to add load capacitors to the crystal for frequency tuning, because they are already integrated in the chip. Using an RTC crystal will provide the lowest current consumption to V_BCKP in case of a power failure. On the other hand, it will increase the BOM costs and requires space for the RTC crystal.

Figure 4: RTC crystal

2.4.2 RTC derived from the system clock: “single crystal” feature

The crystal based EVA-8M / EVA-M8M GNSS modules can be configured in such way that the reference frequency for the RTC is internally derived from the 26 MHz crystal oscillator. For this feature RTC_I must be connected to ground and RTC_O left open. The capacity of the backup battery at V_BCKP must be dimensioned accordingly, taking into account the higher than normal current consumption at V_BCKP in the event of power failure at VCC_IO.

☞ Deriving RTC clock from internal oscillator is not available on TCXO based EVA-M8Q module. ☞ With EVA-8M / EVA-M8M modules the single crystal feature can be configured by sending the

following sequence to the receiver: B5 62 06 41 0C 00 00 00 03 1F 06 C3 CC B4 FF FF FD FF B8 CF

☞ Applying this sequence results in a permanent change and cannot be reversed. An unstable supply

voltage at the VCC_IO pin while applying this sequence can also damage the receiver.

2.4.3 RTC using an external clock

Some applications can provide a suitable 32.768 kHz external reference to drive the module RTC. The external reference can simply be connected to the RTC_I pin. Make sure that the 32.768 kHz reference signal is always turned on and the voltage at the RTC_I pin does not exceed 350 mVpp. Adjusting of the voltage level (typ. 200 mVpp) can be achieved with a resistive voltage divider followed by a DC blocking capacitor in the range of 1 nF to 10 nF. Also make sure the frequency versus temperature behavior of the external clock is within the recommended crystal specification shown in section B.1.

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2.4.4 Time aiding

Time can also be sent by UBX message at every startup of the EVA-8M / EVA-M8 series GNSS modules. This can be done to enable warm starts, AssistNow Autonomous and AssistNow Offline. This can be done when no RTC is maintained.

To enable hot starts correctly, the time information must be known accurately and thus the TimeMark feature has to be used.

For more information about time aiding or timemark see the

Including Protocol Specification

[3].

u-blox 8 / u-blox M8 Receiver Description

☞ For information of this use case, it is mandatory to contact u-blox support team. ☞ For Power Save Mode operations where the RTC is needed, the time aiding cannot be used. This is

because the host does not have any information about when the EVA-8M / EVA-M8 series GNSS modules turn from OFF status to ON status during ON/OFF operation of Power Save Mode.

2.5 RF input

The EVA-8M / EVA-M8 series GNSS module RF-input is already matched to 50 Ω and has an internal DC block. To achieve the performance values as written in the

8M Data Sheet

antenna in front of EVA-8M / EVA-M8M GNSS module (must have a noise figure below 1dB). EVAM8Q with the passive antenna an external LNA is only recommended.

The EVA-M8 series GNSS modules can receive and track multiple GNSS system (e.g. GPS, Galileo, GLONASS, BeiDou and QZSS signals). Because of the dual-frequency RF front-end architecture, two GNSS signals (GPS L1C/A, GLONASS L1OF, Galileo E1B/C and BeiDou B1) can be received and processed concurrently. This concurrent operation is extended to 3 GNSS when GPS and Galileo are used in addition to GLONASS or BeiDou

The EVA-8M can receive GPS L1C/A and GLONASS L1OF signals. However, because of differing center frequencies, the receiver has to be switched to GPS or GLONASS mode by using a UBX message.

[2], an active antenna with a good LNA inside or the mandatory LNA with passive

EVA-M8 Data Sheet

[1] and the

EVA-

☞ Concurrent reception of both GPS and GLONASS is not possible with the EVA-8M.

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 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. These active antenna supervisor circuits also make sure that the active antenna is turned off in Power Save Mode stages.

2.5.2 Passive Antenna

If a passive antenna is connected to a EVA-8M / EVA-M8M series GNSS module, it is mandatory to use an additional LNA in front of module to achieve the performance values as written in the

Data Sheet

external LNA is only recommended. An LNA (U1) alone would make the modules more sensitive to outband jammers, so an additional GNSS SAW filter (F1) has to be connected between the external LNA (U1) and the EVA-8M / EVA-M8M series GNSS module RF-input. If strong out-band jammers are close to the GNSS antenna (e.g. a GSM antenna), see section 2.5.3.

The LNA (U1) can be selected to deliver the performance needed by the application in terms of:

• Noise figure (sensitivity)

[1] and the

EVA-8M Data Sheet

[2], see Annex A. EVA-M8Q with passive antenna, an

EVA-M8

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• 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.

If Power Save Mode is used and the minimum current consumption has to be achieved, then the external LNA should also be turned off. 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 be “low” to turn off.

☞ The function of the ANT_OFF pin can be inverted by sending the following sequence to the

receiver: B5 62 06 41 0C 00 00 00 03 1F 90 47 4F B1 FF FF EA FF 33 98

☞ Applying this sequence results in a permanent change and cannot be reversed. An unstable supply

voltage at the VCC_IO pin while applying this sequence can also damage the receiver.

☞ A pull-down resistor (R7) is required to ensure correct operation of the ANT_OFF pin.

ESD discharge into the RF input cannot always be avoided during assembly and / or field use with this approach! 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 GNSS antenna (e.g. a GSM antenna) GNSS performance can be degraded or the maximum input power of the EVA-8M / EVA-M8 series GNSS modules RFinput can be exceeded. An additional SAW filter (F2) has to put in front of the external LNA (U1), see Appendix A. If the external LNA can accept the maximum input power, the SAW filter between the passive antenna and external LNA (LNA1) might not be necessary. This results in a better noise figure than an additional SAW filter (F2) in front of the external LNA (U1).

If the EVA-8M / EVA-M8 series GNSS module is exposed to an interference environment, it is recommended to use additional filtering. Improved interference immunity with good GNSS performance can be achieved when using a SAW/LNA/SAW configuration between the antenna and the RF-input. The single-ended SAW filter (F2) can be placed in front of the LNA matching network to prevent receiver blocking due to strong interference, see Figure 15.

It should be noted that the insertion loss of SAW filter (F2) directly affects the system noise figure and hence the system performance. Choice of a component with low insertion loss is mandatory when a passive antenna is used with this set-up. An example schematic for an improved jamming immunity is shown in Appendix A.3 (see Figure 15).

2.6 Safe Boot Mode (SAFEBOOT_N)

If the SAFEBOOT_N pin is “low” at start up, the EVA-8M / EVA-M8 series GNSS modules start in Safe Boot Mode and doesn’t begin GNSS operation. In Safe Boot Mode the module runs from an internal LC oscillator and starts regardless of any configuration provided by the configuration pins. Thus, it can be used to recover from situations where the SQI Flash has become corrupted.

Owing to the inaccurate frequency of the internal LC oscillator, the module is unable to communicate via USB in Safe Boot Mode. For communication by UART in Safe Boot Mode, a training sequence (0x 55 55 at 9600 baud) can be sent by the host to the EVA-8M / EVA-M8 series GNSS modules 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 receiver. For further information see the

Description Including Protocol Specification

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[3].

u-blox 8 / u-blox M8 Receiver

EVA-8M and EVA-M8 series - Hardware Integration Manual

Safe Boot Mode is used in production to program the SQI Flash. It is recommended to have the possibility to pull the SAFEBOOT_N pin “low” when the module starts up. This can be provided using an externally connected test point or via a host CPUs digital I/O port.

2.7 System Reset (RESET_N)

The EVA-8M / EVA-M8 series GNSS modules provide a RESET_N pin to reset the system. The RESET_N is an input-only with internal pull-up resistor. It must be at low level for at least 10 ms to

make sure RESET_N is detected. It is used to reset the system. Leave RESET_N open for normal operation. The RESET_N complies with the VCC_IO level and can be actively driven high.

☞ RESET_N should be only used in critical situations to recover the system. The Real-Time Clock

(RTC) will also be reset and thus immediately afterwards the receiver cannot perform a Hot Start.

☞ In reset state, the module consumes a significant amount of current. It is therefore recommended

to use RESET_N only as a reset signal and not as an enable/disable.

2.8 Design-in checklist

2.8.1 General considerations

Check power supply requirements and schematic:

 Is the power supply voltage within the specified range? See how to connect power in Section 2.1.  For USB devices: Is the voltage VDD_USB voltage within the specified range? Do you have a Bus

or Self powered setup?

 Compare the peak current consumption of EVA-8M / EVA-M8 series GNSS modules with the

specification of your power supply.

 GNSS receivers require a stable power supply. Avoid series resistance in your power supply line

(the line to VCC) to minimize the voltage ripple on VCC.

Backup battery

 For achieving a minimal Time To First Fix (TTFF) after a power down (warm starts, hot starts),

make sure to connect a backup battery to V_BCKP, and use an RTC. If not used, make sure

V_BCKP is connected to VCC_IO.

Antenna/ RF input

 The total noise figure including external LNA (or the LNA in the active antenna) should be around

1 dB.

 With the EVA-8M / EVA-M8 series GNSS module, an external LNA is mandatory if no active

antenna is used to achieve the performance values as written in the the

EVA-8M Data Sheet

 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 more information dealing with interference issues see the

[2] .

GPS Antenna Application Note

EVA-M8 Data Sheet

[1] and

[4]

Schematic

 Inner pins of the package must all be connected to GND.

2.8.2 Schematic design-in for EVA-8M / EVA-M8 series GNSS modules

For a minimal design with the EVA-8M / EVA-M8 series GNSS modules, the following functions and pins need to be considered:

• Connect the power supply to VCC, VCC_IO and V_BCKP.

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• VDD_USB: Connect the USB power supply to a LDO before feeding it to VDD_USB and VCC or

connect it to GND if USB is not used.

• Ensure an optimal ground connection to all ground pins of the EVA-8M / EVA-M8 series GNSS

modules.

• Choose the required serial communication interfaces (UART, USB, SPI or DDC) and connect the

appropriate pins to your application

• If you need hot or warm start in your application, connect a Backup Battery to V_BCKP and add

RTC circuit.

• If antenna bias is required, see Appendix A.4.

2.9 Pin description

Pin # Name I/O Description Remark

1 RF_IN I RF Input Add external LNA and SAW if no active antenna

used.

2 GND I Ground Outer ground pin

3 Reserved I/O Reserved Do not connect. Must be left open!

4 Reserved I/O Reserved Do not connect. Must be left open!

5 USB_DM I/O USB data Leave open if not used.

6 USB_DP I/O USB data Leave open if not used.

7 VDD_USB I USB Interface power Connect to GND if not used.

8 RTC_O O RTC Output Leave open if no RTC Crystal attached.

9 RTC_I I RTC Input Connect to GND if no RTC Crystal attached.

10 Reserved I/O Reserved Do not connect. Must be left open!

11 Reserved I/O Reserved Do not connect. Must be left open!

12 PIO14 / ANT_DET I Antenna detection Leave open if not used.

13 PIO13 / EXTINT I External interrupt Leave open if not used.

14 RESET_N I System reset See section 2.7.

15 RXD / SPI MOSI I Serial interface See section 2.2.

16 TXD / SPI MISO O Serial interface See section 2.2.

17 Reserved I/O Reserved Do not connect. Must be left open!

18 GND I Ground Outer ground pin

19 VCC I Main supply See section 2.1.

20 VCC_IO I I/O Supply See section 2.1.

21 V_BCKP I Backup supply See section 2.1.

22 SQI_D0 I/O Data line 0 to external SQI flash

memory or reserved configuration pin.

23 SQI_CLK I/O Clock for external SQI flash memory or

configuration pin.

24 SQI_D2 I/O Data line 2 to external SQI flash

memory or reserved configuration pin.

25 SQI_D1 I/O Data line 1 to external SQI flash

memory or reserved configuration pin.

26 SQI_CS_N I/O Chip select for external SQI flash

memory or configuration enable pin.

27 SQI_D3 I/O Data line 3 to external SQI flash

memory or reserved configuration pin.

28 Reserved I/O Reserved Do not connect. Must be left open!

29 SCL / SPI CLK I Serial interface See section 2.2.

30 SDA / SPI CS_N I/O Serial interface See section 2.2.

Leave open if not used.

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31 TIMEPULSE O Time pulse output Leave open if not used.

32 D_SEL I Interface selector See section 2.2.

33 SAFEBOOT_N I Used for programming the SQI flash

memory and testing purposes.

34 ANT_OK I Antenna status Leave open if not used.

35 ANT_OFF O Antenna control Leave open if not used.

36 Reserved I/O Reserved Do not connect. Must be left open!

37 GND I Ground Inner ground pin

38 GND I Ground Inner ground pin

39 GND I Ground Inner ground pin

40 GND I Ground Inner ground pin

41 GND I Ground Inner ground pin

42 GND I Ground Inner ground pin

43 GND I Ground Inner ground pin

Table 5: EVA-8M / EVA-M8 series GNSS modules pin description

Leave open if not used.

2.9.1 Pin name changes

Selected EVA-M8M pin names have been updated to agree with a common naming convention across u-blox modules. The pins have not changed their operation and are the same physical hardware but with updated names. The table below lists those pins along with their old and new names.

No Previous Name New name

7 V_USB VDD_USB

15 RX / MOSI RXD / SPI MOSI

16 TX / MISO TXD / SPI MISO

26 SQI_CS SQI_CS_N

29 SCL / SCK SCL / SPI CLK

30 SDA / CS_N SDA / SPI CS_N

Table 6: EVA-M8M pin name changes

☞ For more information about pin assignment see the

Sheet

[2]

EVA-M8 Data Sheet

[1] and the

EVA-8M Data

2.10 Layout design-in checklist

Follow this checklist for the layout design to get an optimal GNSS performance.

Layout optimizations (Section 2.11)

 Is the EVA-8M / EVA-M8 module placed according to the recommendation in section 2.11.3?  Is the grounding concept optimal?  Has the 50 Ω line from antenna to module (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).  Keep power supply line as short as possible.  Design a GND guard ring around the optional RTC crystal lines and GND below the RTC circuit.  Add a ground plane underneath the GNSS module to reduce interference. This is especially

important for the RF input line.

 For improved shielding, add as many vias as possible around the micro strip/coplanar waveguide,

around the serial communication lines, underneath the GNSS module, etc.

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Pin36

Calculation of the micro strip for RF input

 The micro strip / coplanar waveguide must be 50 Ω 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 layer) for the micro strip / coplanar waveguide calculation.

 If the distance between the micro strip and the adjacent GND area (on the same layer) does not

exceed 5 times the track width of the micro strip, use the “Coplanar Waveguide” model in AppCad to calculate the micro strip and not the “micro strip” model.

2.11 Layout

This section provides important information for designing a reliable and sensitive GNSS system.

GNSS signals at the surface of the earth are about 15 dB below the thermal noise floor. Signal loss at the antenna and the RF connection must be minimized as much as possible. When defining a GNSS receiver layout, the placement of the antenna with respect to the receiver, as well as grounding, shielding and jamming from other digital devices are crucial issues and need to be considered very carefully.

2.11.1 Footprint

Figure 5: Recommended footprint (bottom view)

Units are in mm.

2.11.2 Paste mask

Pin 1

The paste mask shall be 50 µm smaller than the copper pads with a paste thickness of 100 µm.

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☞ 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.

2.11.3 Placement

A very important factor in achieving maximum GNSS performance is the placement of the receiver on the PCB. The connection to the antenna must be as short as possible to avoid jamming into the very sensitive RF section.

Make sure that RF critical circuits are clearly separated from any other digital circuits on the system board. To achieve this, position the receiver digital part towards your digital section of the system PCB. Care must also be exercised with placing the receiver in proximity to 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 the GNSS performance. For best performance

avoid high temperature drift and air vents near the module.

2.12 Migration considerations

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 8 / u-blox M8 modules as fully compatible as possible with u-blox 7 versions. If using BeiDou, check the bandwidth of the external RF components and the antenna. For power consumption information, see the

Sheet

[2].

The EVA-M8M and EVA-M8Q GNSS modules provide flash firmware update capabilities when connecting an external SQI flash memory device. 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 EVA-7M design which makes use of the single crystal feature, cannot be migrated to EVA-

M8Q! Because single crystal feature is not supported on EVA-M8Q.

☞ For an overall description of the module software operation, see the

Description Including Protocol Specification

☞ For migration, see the

u-blox 7 to u-blox 8 / u-blox M8 Software Migration Guide

2.12.1 Hardware migration from EVA-7M to EVA-8M / EVA-M8M / EVA-M8Q

EVA-7M EVA-8M / EVA-M8M / EVA-M8Q

Pin Name Typical Assignment Pin Name Typical Assignment Remarks for

1 RF input Add external LNA and

SAW if no active antenna used

2 GND Ground GND Ground No difference

3 Reserved Leave open. Reserved Leave open. No difference

4 Reserved Leave open. Reserved Leave open. No difference

RF input Add external LNA and SAW if no active

[3].

EVA-M8 Data Sheet

antenna used

[1] and the

EVA-8M Data

u-blox 8 / u-blox M8 Receiver

[7].

Migration

EVA-8M / EVA-M8M require external LNA passive antenna is used. External LNA is recommended for EVA-M8Q.

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Input voltage for backup

EVA-7M EVA-8M / EVA-M8M / EVA-M8Q

Pin Name Typical Assignment Pin Name Typical Assignment Remarks for

Migration

5 USB_DM USB data USB_DM USB Data No difference

6 USB_DP USB data USB_DP USB Data No difference

7 V_USB USB supply VDD_USB USB supply No difference

8 RTC_O Leave open if no RTC

Crystal attached.

9 RTC_I Connect to GND if no

RTC Crystal attached.

10 Reserved Leave open. Reserved Leave open. No difference

11 Reserved Leave open. Reserved Leave open. No difference

12 PIO14 /

ANT_DET

13 PIO13 /

EXTINT

14 RESET_N Leave open. RESET_N Leave open. No difference

15 RX / MOSI Serial Interface RXD / SPI MOSI Serial Interface No difference

16 TX / MISO Serial Interface TXD / SPI MISO Serial Interface No difference

17 Reserved Serial Interface Reserved Leave open. No difference

18 GND Ground GND Ground No difference

19 VCC Main voltage supply

20 VCC_IO Supply voltage for PIOs

21 V_BCKP

22 Reserved Leave open. SQI_D0 Data line 0 to external SQI flash

23 Reserved Leave open. SQI_CLK Clock for external SQI flash memory or

24 Reserved Leave open. SQI_D2 Data line 2 to external SQI flash

25 Reserved Leave open. SQI_D1 Data line 1 to external SQI flash

26 Reserved Leave open. SQI_CS_N Chip select for external SQI flash

27 Reserved Leave open. SQI_D3 Data line 3 to external SQI flash

28 Reserved Leave open. Reserved Leave open. No difference

29 SCL / SCK Serial Interface SCL / SPI CLK Serial interface

30 SDA / CS_N Serial Interface SDA / SPI CS_N Serial interface

31 TIMEPULSE Time pulse output TIMEPULSE Time pulse output No difference

32 D_SEL Interface selector D_SEL Interface selector

33 Reserved Leave open SAFEBOOT_N Used for programming the SQI flash

Antenna detection PIO14 /

External Interrupt PIO13 / EXTINT External Interrupt No difference

EVA-7M 1.65 - 3.6V

EVA-7M 1.65 – 3.6V

mode. EVA-7M 1.4 – 3.6V

RTC_O Leave open if no RTC Crystal attached. No difference

RTC_I Connect to GND if no RTC Crystal

attached.

Antenna detection No difference

ANT_DET

VCC Main voltage supply

EVA-8M / EVA-M8M / 1.65 - 3.6V

EVA-M8Q 2.7 - 3.6V Note: EVA-M8Q has a

VCC_IO Supply voltage for PIOs

EVA-8M / EVA-M8M 1.65 - 3.6V

EVA-M8Q 2.7 – 3.6V Note: EVA-M8Q has a

V_BCKP Input voltage for backup mode

EVA-8M / EVA-M8M / EVA-M8Q

1.4 – 3.6V

memory or reserved configuration pin

configuration pin.

memory or reserved configuration pin.

memory or configuration enable pin.

memory or reserved configuration pin.

memory and testing purposes.

No difference

higher voltage range

No difference

higher voltage range

No difference

Leave open if not used.

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EVA-7M EVA-8M / EVA-M8M / EVA-M8Q

Pin Name Typical Assignment Pin Name Typical Assignment Remarks for

Migration

34 ANT_OK Antenna status ANT_OK Antenna status No difference

35 ANT_OFF Antenna control ANT_OFF Antenna control No difference

36 Reserved Leave open. Reserved Leave open. No difference

37 GND Ground GND Ground No difference

38 GND Ground GND Ground No difference

39 GND Ground GND Ground No difference

40 GND Ground GND Ground No difference

41 GND Ground GND Ground No difference

42 GND Ground GND Ground No difference

43 GND Ground GND Ground No difference

Table 7: Pin-out comparison EVA-7M vs. EVA-8M / EVA-M8M / EVA-M8Q

2.12.2 C88-M8M - Evaluating EVA-M8M on existing NEO-xM sockets

The C88-M8M GNSS application board is designed for easier evaluation and design-in of u-blox EVAM8M modules in existing NEO-xM modules based products. The C88-M8M series integrates the EVAM8M GNSS modules into a NEO form factor adaptor board (i.e. with the same dimensions and pinout as the NEO-6M, NEO-7M and NEO-M8M). The C88-M8M application board allows straightforward integration of the u-blox EVA-M8M modules in customers’ existing end products based on the u-blox NEO GNSS modules. It enables fast verification of the EVA-M8M functionalities and performances before the design-in.

☞ Schematic of C88-M8M is available upon request.

NEO-6M C88-M8M

Pin Name Typical Assignment Pin Name Typical Assignment Remarks for Migration

1 RESERVED SAFEBOOT_N

(Leave open)

2 SS_N SPI Slave Select D_SEL Leave open. If

3 TIMEPULSE Time pulse (1PPS) TIMEPULSE Time pulse (1PPS) No difference

4 EXTINT0 External interrupt pin EXTINT0 External interrupt pin No difference

5 USB_DM USB data USB_DM USB Data No difference

6 USB_DP USB data USB_DP USB Data No difference

7 VDD_USB USB supply VDD_USB USB supply No difference

8 RESERVED Pin 8 and 9 must be

connected together.

9 VCC_RF Can be used for active

antenna or external LNA supply.

10 GND GND GND GND No difference

11 RF_IN GPS signal input RF_IN GPS signal input For designs with a passive antenna

RESERVED SAFEBOOT_N

(Leave open)

connected to GND SPI interface available on Pins 18-21.

RESET_N Reset input If pin 8 is connected to pin 9 on C88-

VCC_RF Can be used for active

antenna or external LNA supply.

No difference

Different functions. Only compatible if this pin is left open!

M8M, the device always runs. With NEO-6Q, if Reset input is used, it implements the 3k3 resistor from pin 8 to pin 9. This also works with NEO-7N. If used with NEO-7N, do not populate the pull-up resistor.

No difference

directly connected to the RF_IN pin, an additional LNA in front of C88-M8M is

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NEO-6M C88-M8M

Pin Name Typical Assignment Pin Name Typical Assignment Remarks for Migration

recommended in order to achieve the performance values shown in the

M8 Data Sheet

of the C88-M8M is about 2 dB higher than NEO-6M.

12 GND GND GND GND No difference

13 GND GND GND GND No difference

14 MOSI/

CFG_COM0

15 MISO/

CFG_COM1

16 CFG_GPS0/

SCK

17 RESERVED Leave open. RESERVED Leave open. No difference

18 SDA DDC Data SDA DDC Data / SPI CS_N No difference if pin 2 is left open. If pin

19 SCL DDC Clock SCL DDC Clock / SPI SCK No difference for DDC. If pin 2 low =

20 TxD Serial Port TxD Serial Port / SPI MISO No difference for UART. If pin 2 low =

21 RxD Serial Port RxD Serial Port / SPI MOSI No difference for UART. If pin 2 low =

22 V_BCKP Backup supply voltage V_BCKP Backup supply voltage No difference

23 VCC Supply voltage VCC Supply voltage

24 GND GND GND GND No difference

Table 8: Replacing NEO-6M by C88-M8M

SPI MOSI / Configuration pin. Leave open if not used.

SPI MISO / Configuration pin. Leave open if not used.

Power Mode Configuration pin / SPI Clock. Leave open if not used.

RESERVED Leave open. Different functions. Only compatible if

this pin is left open!

RESERVED Leave open. Different functions. Only compatible if

this pin is left open!

RESERVED Leave open. Different functions. Only compatible if

this pin is left open!

2 low = SPI chip select.

SPI clock.

SPI MISO.

SPI MOSI.

[1]. The Noise Figure

EVA

☞ NEO-6M cannot be replaced by C88-M8M if SPI interface or configuration pins (pin 2, pin 14, pin

15 and pin 16) are used.

☞ For the existing NEO-7M and NEO-M8M designs, C88-M8M is one to one compatible with the

exception of some performance difference.

2.13 EOS/ESD/EMI precautions

When integrating GNSS receivers into wireless systems, careful consideration must be given to electromagnetic and voltage susceptibility issues. Wireless systems include components which can produce Electrostatic Discharge (ESD), Electrical Overstress (EOS) and Electro-Magnetic Interference (EMI). CMOS devices are more sensitive to such influences because their failure mechanism is defined by the applied voltage, whereas bipolar semiconductors are more susceptible to thermal overstress. The following design guidelines are provided to help in designing robust yet cost effective solutions.

⚠ To avoid overstress 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 exceed the maximum input

power as specified in the

EVA-M8 Data Sheet

[1] and the

EVA-8M Data Sheet

[2].

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Passive antennas

Active Antennas

A B

LNA with appropriate ESD rating

RF ESD protection diode

Passive antennas

Active Antennas

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. 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 Electrostatic Discharge (ESD). Special precautions are required

when handling.

Most defects caused by ESD can be prevented by following strict ESD protection rules for production and handling. When implementing passive antenna patches or external antenna connection points, then additional ESD measures as shown in Figure 6 can also avoid failures in the field.

Figure 6: ESD Precautions

2.13.3 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 emitters are close to a GNSS receiver or its antenna. EOS causes damage to the chip structures.

If the RF_IN is damaged by EOS, it’s hard to determine whether the chip structures have been damaged by ESD or EOS.

2.13.4 EOS protection measures

EOS protection measures as shown in Figure 7 are recommended for any designs combining wireless communication transceivers (e.g. GSM, GPRS) and GNSS in the same design or in close proximity.

(without internal filter which need the module antenna supervisor circuits)

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LNA with appropriate ESD

rating and maximum input power.

Figure 7: EOS and ESD Precautions

2.13.5 Electromagnetic interference (EMI)

Electromagnetic interference (EMI) is the addition or coupling of energy, which causes a spontaneous reset of the GNSS receiver or results in unstable performance. In addition to EMI degradation due to self-jamming (see section 2.3.4), any electronic device near the GNSS receiver can emit noise that can lead to EMI disturbances or damage.

The following elements are critical regarding EMI:

• Unshielded connectors (e.g. pin rows etc.)

• Weakly shielded lines on PCB (e.g. on top or bottom layer and especially at the border of a PCB)

• Weak GND concept (e.g. small and/or long ground line connections)

EMI protection measures are recommended when RF emitting devices are near the GNSS receiver. To minimize the effect of EMI a robust grounding concept is essential. To achieve electromagnetic robustness follow the standard EMI suppression techniques.

http://www.murata.com/products/emc/knowhow/index.html

http://www.murata.com/products/emc/knowhow/pdf/4to5e.pdf

Improved EMI protection can be achieved by inserting a resistor or better yet a ferrite bead or an inductor (see Table 16) into any unshielded PCB lines connected to the GNSS receiver. Place the resistor as close as possible to the GNSS receiver pin.

Alternatively, feed-thru capacitors with good GND connection can be used to protect e.g. the VCC supply pin against EMI. A selection of feed-thru capacitors are listed in Table 24.

Intended use

☞ In order to mitigate any performance degradation of a radio equipment under EMC disturbance,

system integration shall adopt appropriate EMC design practice and not contain cables over three meters on signal and supply ports.

2.13.6 Applications with cellular modules

GSM terminals transmit power levels up to 2 W (+33 dBm) peak, 3G and LTE up to 250 mW continuous. Consult the corresponding product data sheet in Related documents for the absolute maximum power input at the GNSS receiver. 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 [6].

2.13.6.1 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. 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 Murata.

2.13.6.2 Increasing interference immunity

Interference signals come from in-band and out-band frequency sources.

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1525

1550

1625

GPS

input filter

cha racte ristics

1575

1600

-110

Jammi n g signal

1525

1550

1625

Frequency [MHz]

Power [dBm]

GPS input filte r cha racte ristics

1575 1600

Interference

signal

GPS

signals

GPS Car ri er

1575.4 MHz

2.13.6.3 In-band interference

With in-band interference, the signal frequency is very close to the GPS frequency of 1575 MHz (see Figure 8). Such interference signals are typically caused by harmonics from displays, micro-controller, bus systems, etc.

Figure 8: In-band interference signals

Figure 9: In-band interference sources

Measures against in-band interference include:

• Maintaining a good grounding concept in the design

• Shielding

• Layout optimization

• Filtering e.g. resistors and ferrite beads

• Placement of the GNSS antenna

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

2.13.6.4 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.

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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 2.13.6) into the antenna input line to the GNSS receiver (see Figure 11).

Figure 11: Measures against out-band interference

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•

GND

Local GND

•

• When soldering RF connectors and patch antennas to the

3 Product handling & soldering

3.1 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-8M Data Sheet

[2].

3.2 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. The main principle of an EPA is that there are no highly charging materials in the vicinity of ESD sensitive electronics, all conductive materials are grounded, workers are grounded, and charge build-up on ESD sensitive electronics is prevented. International standards are used to define typical EPA and can be obtained for example from International Electrotechnical Commission (IEC) or American National Standards Institute (ANSI).

GNSS receivers are sensitive to ESD and require special precautions when handling. Particular care must be exercised 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.

EVA-M8 Data Sheet

[1] and the

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.

• Before mounting an antenna patch, connect ground of the device.

When handling the RF pin, do not come into contact with any charged capacitors and be careful when contacting materials that can develop charges (e.g. patch antenna ~10 pF, coax cable ~50-80 pF/m, soldering iron, …)

To prevent electrostatic discharge through the RF input, do not touch the mounted patch antenna.

receiver’s RF pin, make sure to use an ESD safe soldering iron (tip).

⚠ Failure to observe these precautions can result in severe damage to the GNSS receiver!

3.3 Soldering

3.3.1 Soldering paste

Use of "No Clean" soldering paste is strongly recommended, as it does not require cleaning after the soldering process has taken place. The paste listed in the example below meets these criteria.

Soldering Paste: OM338 SAC405 / Nr.143714 (Cookson Electronics) Alloy specification: Sn 95.5/ Ag 4/ Cu 0.5 (95.5% Tin/ 4% Silver/ 0.5% Copper) Melting Temperature: 217° C Stencil Thickness: 100 to 150 µm for base boards

The final choice of the soldering paste depends on the approved manufacturing procedures.

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The paste-mask geometry for applying soldering paste should meet the recommendations given in section 2.11.2.

3.3.2 Reflow soldering

Condition Abbreviation Recommendation

Preheat/ Soak Temperature min. Preheat/ Soak Temperature max. Preheat/ Soak Time from T

Liquidus Temperature Time maintained above T

Peak Package Body Temperature TP 250°C

Ramp up rate (TL to TP) 3°C/ second max.

Time within +0°C…-5°C of TP 30 seconds

Ramp down rate (TP to TL) 4°C/ second max.

Table 9: Recommended conditions for reflow process

to T

smin

smax

T T T

T t

smin

smax

smin

to T

smax

150°C 180°C

)

< 90 seconds

217°C 40 to 60 seconds

The peak temperature must not exceed 250°C. The time above 245°C must not exceed 30 seconds.

☞ EVA-8M / EVA-M8 series GNSS modules must not be soldered with a damp heat process.

3.3.3 Optical inspection

After soldering the modules, consider an optical inspection step to check whether:

• The module is properly aligned and centered over the pads

3.3.4 Repeated reflow soldering

Only single reflow soldering process is recommended for boards populated with EVA-8M / EVA-M8 series GNSS 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-8M / EVA-M8 series GNSS modules.

3.3.6 Rework

Not recommended.

3.3.7 Use of ultrasonic processes

Some components on the EVA-8M / EVA-M8 series GNSS 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-8M / EVA-M8 series GNSS modules caused

by any Ultrasonic Processes.

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GNSS generator. It assures

4 Product testing

4.1 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.

An OEM manufacturer should focus on:

• Overall sensitivity of the device (including antenna, if applicable)

• Communication to a host controller

4.2 System sensitivity test

The best way to test the sensitivity of a GNSS device is with the use of a Multireliable and constant signals at every measurement.

u-blox recommends the following Multi-GNSS generator:

• Spirent GSS6300 Spirent 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 the NMEA GSV or the UBX-NAV-SVINFO message (e.g. with u-center).

5. Compare the results to a “Golden Device” or the u-blox EVA-8M / EVA-M8 series Evaluation Kits.

4.2.2 ‘Go/No go’ tests for integrated devices

The best test is to bring the device to an outdoor position with excellent sky view (HDOP < 3.0). Let the receiver acquire satellites and compare the signal strength with a “Golden Device”.

☞ As the electro-magnetic field of a redistribution antenna is not homogenous, indoor tests are in

most cases not reliable. These kind of tests may be useful as a ‘go/no go’ test but not for sensitivity measurements.

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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

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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

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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

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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

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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

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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

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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

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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

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B Component selection

This section provides information about components that are critical for the performance of the EVA-8M / EVA-M8 series GNSS modules. 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 … +85 C) are provided.

B.1 External RTC (Y1)

ID Parameter Value

1 Frequency Specifications

1.1 Oscillation mode Fundamental Mode

1.2 Nominal frequency at 25 ºC 32.768 kHz

1.3 Frequency calibration tolerance at 25 ºC < ±100 ppm

2 Electrical specifications

2.1 Load capacitance CL 7 pF

2.2 Equivalent series resistance RS

Table 10: RTC crystal specifications

< 100 kΩ

Manufacturer Order No.

Micro Crystal CC7V-T1A 32.768 kHz 7.0 pF +/- 100 ppm

Table 11: 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

TDK/ EPCOS B3913:

B39162B3913U410

TDK/ EPCOS B9416:

B39162B9416K610

TDK/ EPCOS B4310:

B39162B4310P810

TDK/ EPCOS B4327:

B39162B4327P810

TDK/ EPCOS B9482:

B39162B9482P810

muRata SAFFB1G56KB0F0A GPS+GLONASS+BeiDou Low insertion loss, Only for mobile application

muRata SAFEA1G58KA0F00 GPS+GLONASS Only for mobile application

muRata SAFFB1G58KA0F0A GPS+GLONASS Only for mobile application

Triquint 856561 GPS Compliant to the AEC-Q200 standard

TAI-SAW TA1573A GPS+GLONASS Low insertion loss

TAI-SAW TA1343A GPS+GLONASS+BeiDou Low insertion loss

Table 12: Recommend parts list for RF band-pass filter

GPS+GLONASS High attenuation

GPS+GLONASS+BeiDou For automotive application

GPS High input power

GPS+GLONASS Compliant to the AEC-Q200 standard

GPS+GLONASS+BeiDou Low insertion loss

GPS+GLONASS Low insertion loss

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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

TDK/ EPCOS B3913: B39162B3913U410 GPS+GLONASS+BeiDou For automotive application

TDK/ EPCOS B4310: B39162B4310P810 GPS+GLONASS Compliant to the AEC-Q200 standard

TDK/ EPCOS B4327: B39162B4327P810 GPS+GLONASS+BeiDou Low insertion loss

TDK/ EPCOS B9850: B39162B9850P810 GPS Low insertion loss

TDK/ EPCOS B8400: B39162B8400P810 GPS ESD protected and high input power

TDK/ EPCOS B9416: B39162B9416K610 GPS High input power

muRata SAFFB1G56KB0F0A GPS+GLONASS+BeiDou Low insertion loss, Only for mobile application

muRata SAFEA1G58KB0F00 GPS+GLONASS Low insertion loss, only for mobile application

muRata SAFEA1G58KA0F00 GPS+GLONASS High attenuation, only for mobile application

muRata SAFFB1G58KA0F0A 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 13: Recommended parts for the LNA protection filter

B.4 USB line protection (D2)

Manufacturer Order No.

ST Microelectronics USBLC6-2

Table 14: Recommend parts list for USB line protection

B.5 USB LDO (U1)

Manufacturer Order No.

Seiko Instruments Inc. S-1206B33-I6T2G

Table 15: Recommend parts list for USB LDO

B.6 External LNA (U1)

ID Parameter Value

1 Gain and Noise Figure @ 1.575 GHz

1.1 Gain > 17 dB

1.2 Noise Figure < 2 dB

Table 16: External LNA specifications

Manufacturer Order No. Comments

Maxim MAX2659ELT+ Low noise figure, up to 10 dBm RF input power

JRC New Japan Radio NJG1143UA2 Low noise figure, up to 15 dBm RF input power

NXP BGU8006 Low noise figure, small size

Table 17: Recommend parts list for external LNA

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B.7 Optional SQI Flash (U3)

Manufacturer Order No. Module Comments

Adesto AT25SL641 EVA-M8M 1.8V, 64 Mbit (only 32 Mbit usable), several package/temperature

options

EVA-8M 1.8V, 64 Mbit (only 32 Mbit usable), several package/temperature

options

Gigadevice GD25Q32C All 3V, 32 Mbit, several package/temperature options

Macronix MX25L3233F All 3V, 32 Mbit, several package/temperature options

Macronix MX25V8035F All 3V, 8 Mbit, several package/temperature options

Macronix MX25V1635F All 3V, 16 Mbit, several package/temperature options

Macronix MX25R8035Fxxxx1 All 1.8V and 3V, 8 Mbit, several package/temperature options

Macronix MX25R8035Fxxxx3 All 1.8V and 3V, 8 Mbit, several package/temperature options

Macronix MX25R1635FxxxH1 All 1.8V and 3V, 16 Mbit, several package/temperature options

Spansion/Cypress S25FL116K All 3V, 16 Mbit, several package/temperature options

Spansion/Cypress S25FL132K All 3V, 32 Mbit, several package/temperature options

Winbond W25Q16FW EVA-M8M 1.8V, 16 Mbit, several package/temperature options

EVA-8M 1.8V, 16 Mbit, several package/temperature options

Winbond W25Q80DV All 3V, 8 Mbit, several package/temperature options

Winbond W25Q16JV All 3V, 16 Mbit, several package/temperature options

Winbond W25Q16JVSNIM All 3V, 16 Mbit, several package/temperature options

Winbond W25Q32DW EVA-M8M 1.8V, 32 Mbit, several package/temperature options

EVA-8M 1.8V, 32 Mbit, several package/temperature options

Winbond W25Q32JV All 3V, 32 Mbit, several package/temperature options

Winbond W25Q64JV All 3V, 64 Mbit (only 32Mbit usable) , several package/temperature

options

Table 18: 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 19: Recommend parts list for RF ESD protection diode

B.9 Operational amplifier (U6)

Manufacturer Order No.

Linear Technology LT6000

Linear Technology LT6003

Table 20: Recommend parts list for Operational Amplifier

B.10 Open-drain buffer (U4, U7 and U8)

Manufacturer Order No.

Fairchild NC7WZ07P6X

Table 21: Recommend parts list for open-drain buffer

UBX-16010593 - R06 Appendix Page 43 of 47 Early Production Information

EVA-8M and EVA-M8 series - Hardware Integration Manual

B.11 Antenna supervisor switch transistor (T1)

Manufacturer Order No.

Vishay Si1016X-T1-E3 (p-channel)

Table 22: Recommend parts list for antenna supervisor switch transistor (p-channel MOSFET)

B.12 Ferrite beads (FB1)

Manufacturer Order No. Comments

MuRata BLM15HD102SN1 High impedance @ 1.575 GHz

MuRata BLM15HD182SN1 High impedance @ 1.575 GHz

TDK MMZ1005F121E High impedance @ 1.575 GHz

TDK MMZ1005A121E High impedance @ 1.575 GHz

Table 23: Recommend parts list for ferrite beads FB1

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

MuRata NFM21PC474R1C3 For power supply < 4 A, size 0805

Table 24: Recommend parts list for feed thru capacitors

B.14 Inductor (L1)

Manufacturer Order No.

MuRata LQG15H Series LQG15HS47NJ02 (47 nH, 5%, 300 mA).

LQG15HN27NJ02, LQG15HS27NJ02, LQG15HN33NJ02, LQG15HS33NJ02, LQG15HS39NJ02

MuRata LQW15A Series LQW15AN47NJ80, LQW15AN51NJ80,

LQW15AN53NJ80, LQW15AN56NJ80, LQW15AN68NJ80, LQW15AN75NJ80

Johanson Technology L-07W Series 39 nH L-07W39NJV4T or any other inductor wich

is compatible with the above mentioned MuRata inductors

Table 25: Recommend parts list for inductor

B.15 Standard capacitors

Name Use Type / Value

C0 RF-input DC block COG 47P 5% 25V

C1 Decoupling Capacitor X7R 10N 10% 16V

C24 Decoupling capacitor at VBUS Depends on USB LDO (U1) specification

C23 Decoupling capacitor at VBUS Depends on USB LDO (U1) specification

C4 Decoupling VCC_IO at SQI Flash supply pin X5R 1U0 10% 6.3V

Table 26: Standard capacitors

UBX-16010593 - R06 Appendix Page 44 of 47 Early Production Information

EVA-8M and EVA-M8 series - Hardware Integration Manual

B.16 Standard resistors

Name Use Type / Value

R4 USB data serial termination 27R 5% 0.1W

R5 USB data serial termination 27R 5% 0.1W

R3 Pull-up at antenna supervisor transistor 100K 5% 0.1W

R4 Antenna supervisor current limiter 10R 5% 0.25W

R5 Antenna supervisor voltage divider 560R 5% 0.1W

R6 Antenna supervisor voltage divider 100K 5% 0.1W

R7 Pull-up at LNA enable 10K 5% 0.1W

R11 Pull-down at VDD_USB 100K 5% 0.1W

Table 27: Standard resistors

C Glossary

Abbreviation Definition

ANSI American National Standards Institute

BeiDou Chinese satellite navigation system

CDMA Code Division Multiple Access

EMI Electromagnetic interference

EOS Electrical Overstress

EPA Electrostatic Protective Area

ESD Electrostatic discharge

Galileo European navigation system

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 System

WCDMA Wideband Code Division Multiple Access

Table 28: Explanation of the abbreviations and terms used

UBX-16010593 - R06 Appendix Page 45 of 47 Early Production Information

EVA-8M and EVA-M8 series - Hardware Integration Manual

Revision history

Revision Date Name Comments

R01 31-May-2016 njaf Advance Information

R02 25-Aug-2016 njaf Added EVA-M8Q variant and updated relevant contents

R03 09-Feb-2017 jesk Early Production Information, Updated information about EVA-M8Q VCC,

VCC_IO, and V_BCKP voltage ranges, updated eFuse configuration messages, updated section 2.2.4 and Figure 2 (USB interface), added section 2.12.1 (migration from EVA-7M to EVA-8M/M8M/M8Q), updated Figures in Appendix A (Reference schematics), updated list of compatible SQI flash models, added note about IEC 60950-1 standard to section 2.1.1.1.

R04 11-Nov-2017 msul Updated section 3.3.1 (Soldering paste). Added information on RED DoC in

European Union regulatory compliance (page 2), added Intended use statement in section 2.13 EOS/ESD/EMI precautions, updated legal statement in cover page and added Documentation feedback e-mail address in contacts page.

R05 30-May-2018 jesk Updated EVA-M8Q voltage range in section 2.12.1. Updated supported SQI

Flash list in section B.7.

R06 07-Feb-2019 jesk Clarified alternative uses for the EXTINT pin in section 2.3.2. Updated power

save limitations in section 2.4. Updated supported SQI Flash list in section B.7. Updated the list of recommended inductors in section B.14.

UBX-16010593 - R06 Related documents Page 46 of 47 Early Production Information

EVA-8M and EVA-M8 series - Hardware Integration Manual

Contact

For complete contact information, visit us at www.u-blox.com.

u-blox Offices

North, Central and South America

u-blox America, Inc.

Phone: +1 703 483 3180 E-mail: info_us@u-blox.com

Regional Office West Coast:

Phone: +1 408 573 3640 E-mail: info_us@u-blox.com

Technical Support:

Phone: +1 703 483 3185 E-mail: support@u-blox.com

Headquarters Europe, Middle East, Africa

u-blox AG

Phone: +41 44 722 74 44 E-mail: info@u-blox.com Support: support@u-blox.com

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u-blox Singapore Pte. Ltd.

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

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Phone: +86 10 68 133 545 E-mail: info_cn@u-blox.com Support: support_cn@u-blox.com

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Phone: +86 23 6815 1588 E-mail: info_cn@u-blox.com Support: support_cn@u-blox.com

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Phone: +86 21 6090 4832 E-mail: info_cn@u-blox.com Support: support_cn@u-blox.com

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Phone: +86 755 8627 1083 E-mail: info_cn@u-blox.com Support: support_cn@u-blox.com

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Phone: +91 80 405 092 00 E-mail: info_in@u-blox.com Support: support_in@u-blox.com

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Phone: +81 6 6941 3660 E-mail: Support: support_jp@u-blox.com

Regional Office Japan (Tokyo):

Phone: +81 3 5775 3850 E-mail: info_jp@u-blox.com Support: support_jp@u-blox.com

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Phone: +82 2 542 0861 E-mail: info_kr@u-blox.com Support: support_kr@u-blox.com

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Phone: +886 2 2657 1090 E-mail: info_tw@u-blox.com Support: support_tw@u-blox.com

info_jp@u-blox.com

UBX-16010593 - R06 Contact Page 47 of 47 Early Production Information

u-blox EVA-8M Series, EVA-M8Q, EVA-8M, EVA-M8 Series, EVA-M8M Hardware Integration Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Document Information

Contents

1 Hardware description

1.1 Overview

2 Design-in

2.1 Power management

2.1.1 Overview

2.1.1.1 Main supply voltage (VCC)

2.1.1.2 I/O supply voltage (VCC_IO)

2.1.1.3 Backup power supply (V_BCKP)

2.1.1.4 USB interface power supply

2.1.2 Power management configuration

2.2 Interfaces

2.2.1 UART interface

2.2.2 Display Data Channel (DDC) Interface

2.2.3 SPI Interface

2.2.4 USB interface

2.2.5 SQI Flash memory

2.3 I/O Pins

2.3.1 Time pulse

2.3.2 External interrupt

2.3.3 Active antenna supervisor

2.3.3.1 2-pin antenna supervisor

2.3.3.2 3-pin antenna supervisor

2.3.4 Electromagnetic interference and I/O lines

2.4 Real-Time Clock (RTC)

2.4.1 RTC using a crystal

2.4.2 RTC derived from the system clock: “single crystal” feature

2.4.3 RTC using an external clock

2.4.4 Time aiding

2.5 RF input

2.5.1 Active Antenna

2.5.2 Passive Antenna

2.5.3 Improved Jamming Immunity

2.6 Safe Boot Mode (SAFEBOOT_N)

2.7 System Reset (RESET_N)

2.8 Design-in checklist

2.8.1 General considerations

2.8.2 Schematic design-in for EVA-8M / EVA-M8 series GNSS modules

2.9 Pin description

2.9.1 Pin name changes

2.10 Layout design-in checklist

2.11 Layout

2.11.1 Footprint

2.11.2 Paste mask

2.11.3 Placement

2.12 Migration considerations

2.12.1 Hardware migration from EVA-7M to EVA-8M / EVA-M8M / EVA-M8Q

2.12.2 C88-M8M - Evaluating EVA-M8M on existing NEO-xM sockets

2.13 EOS/ESD/EMI precautions

2.13.1 Electrostatic Discharge (ESD)

2.13.2 ESD protection measures

2.13.3 Electrical Overstress (EOS)

2.13.4 EOS protection measures

2.13.5 Electromagnetic interference (EMI)

2.13.6 Applications with cellular modules

2.13.6.1 Isolation between GNSS and GSM antenna

2.13.6.2 Increasing interference immunity

2.13.6.3 In-band interference

2.13.6.4 Out-band interference

3 Product handling & soldering

3.1 Packaging, shipping, storage and moisture preconditioning

3.2 ESD handling precautions

3.3 Soldering

3.3.1 Soldering paste

3.3.2 Reflow soldering

3.3.3 Optical inspection

3.3.4 Repeated reflow soldering

3.3.5 Wave soldering

3.3.6 Rework

3.3.7 Use of ultrasonic processes

4 Product testing

4.1 Test parameters for OEM manufacturer

4.2 System sensitivity test

4.2.1 Guidelines for sensitivity tests

4.2.2 ‘Go/No go’ tests for integrated devices