u-blox EVA-8M, EVA-M8 User Manual

Abstract

This document describes the hardware features and specifications of u-blox EVA-8M and EVA-M8

series GNSS modules. The EVA series modules boast the industry’s smallest form factor and are a

fully tested standalone solution that requires no host integration. The EVA-8M and EVA-M8 series modules combine excellent GNSS performance with highly flexible power, design, and serial communication options.

www.u-blox.com

UBX-16010593 - R08

EVA-8M and EVA-M8 series

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

Hardware integration manual

EVA-8M and EVA-M8 series - Hardware integration manual

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

R08

28-May-2020

Document status

Production information

Product status

Corresponding content status

In Development / Prototype

Objective Specification

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

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

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.

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

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 of this document or any part thereof is only permitted with the express written permission of u-blox. The information contained herein is provided “as is” and u-blox assumes no liability for its use. No warranty, either express or implied, is given, including but not limited to, with respect to the accuracy, correctness, reliability and fitness for a particular purpose of the information. This document may be revised by u-blox at any time without notice. For the most recent documents, visit www.u-blox.com. Copyright © u-blox AG.

Document information

This document applies to the following products:

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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 checklists .................................................................................................................................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 Layout design-in: Thermal management .............................................................................................22

2.13 Migration considerations ........................................................................................................................22

2.13.1 Hardware migration from EVA-7M to EVA-8M / EVA-M8M / EVA-M8Q ..............................23

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

2.14 EOS/ESD/EMI precautions ......................................................................................................................25

2.14.1 Electrostatic discharge (ESD) ........................................................................................................26

2.14.2 ESD protection measures ...............................................................................................................26

2.14.3 Electrical overstress (EOS) .............................................................................................................26

2.14.4 EOS protection measures ...............................................................................................................26

2.14.5 Electromagnetic interference (EMI) .............................................................................................27

2.14.6 Applications with cellular modules ...............................................................................................27

3 Product handling and 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) ........................................................................................................41

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

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

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

B.7 Optional SQI Flash (U3) ............................................................................................................................42

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 Ferrite beads (FB1) ...................................................................................................................................43

B.12 Antenna supervisor switch transistor (T1) .........................................................................................44

B.13 Feed-through capacitors .........................................................................................................................44

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

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

B.16 Standard resistors ....................................................................................................................................44

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 the 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, 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 keeping AssistNow

data, the EVA-8M / EVA-M8 series GNSS modules must be connected to an external SQI flash memory. Firmware update from SQI flash memory is only supported with EVA-M8M and EVA-M8Q series GNSS modules. For more information about product features, see the EVA-M8 data sheet [1] and the EVA-8M data sheet [2]

☞ 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

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 following subsections explain the different supply voltages.

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

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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 the following step, builtin 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.

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 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.

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 the single crystal feature, see section 2.4.2.

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, that is, powered independently from the USB bus, or it can be bus-powered, that is, powered through the USB connection. In the 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 differs. Some examples are shown in the following sections:

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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

 Single supply voltage for VCC and VCC_IO, no backup supply: see Appendix, Figure 13  Separate supply voltages for VCC, VCC_IO and V_BCKP: see Appendix, Figure 14  Single supply voltage for VCC and VCC_IO, use of a backup supply: see Appendix, Figure 16

☞ For description of the different power operating modes see the EVA-M8 data sheet [1] and the

EVA-8M data sheet [2].

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.

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 available, for example,

USB, 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 GPS Implementation and Aiding Features in u-blox wireless modules [6].

☞ 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

EN 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 EVA-M8 data sheet [1] and the EVA-8M data sheet [2].

☞ 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 supports the full-speed data rate of 12 Mbit/s. It is compatible with the USB 2.0 FS standard. To implement the physical characteristics required by the USB 2.0 specification, the interface requires some external components. Figure 2 shows the interface pins and additional external components. To comply with USB specifications, VBUS must be connected through an LDO (U1) to pin VDD_USB of the module. This ensures that the internal 1.5 kΩ pull-up resistor on USB_DP gets disconnected when the USB host 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, that is, 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 still receives the signal indicating that the device is present and ready to communicate. This can 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.

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).

Figure 2: USB interface

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Name

Component

Function

Comments

LDO

Regulates VBUS (4.4 …5.25

V) down to a voltage of 3.3 V).

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

C24, C23

Capacitors

Required according to the specification of LDO U1.

Protection diodes

Protects circuit from overvoltage / ESD when connecting.

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

R4, R5

Serial termination resistors

Establishes a full-speed

driver impedance of 28…44

Ω.

A value of 27 Ω is recommended.

R11

Resistor

Ensures defined signal at VDD_USB when VBUS is not connected / powered.

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

Table 2: Summary of USB external components

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:

 Stores the current configuration permanently  Saves data logging results  Holds 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 the 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 u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification [3] for setting 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

☞ Applying these sequences results 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 flash firmware is done typically at production. For this purpose the EVAM8M and EVA-M8Q GNSS modules have to enter the safe boot mode. For 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 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. For more information, see the u-blox 8 / ublox M8 Receiver Description Including Protocol Specification [3].

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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Function

I/O

Description

Remarks

ANT_OK

Antenna OK

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

Default configuration

ANT_OFF

Control signal to turn on and off the antenna supply

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

Default configuration

By default, the time pulse signal is disabled. For more information, see the u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification [3].

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

internal pull-up becomes disabled. 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 turns 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-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.

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 (for example, 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 [3].

Open drain buffers U4 and U7 (for example, 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.

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Function

I/O

Description

Remarks

ANT_DET

I (pull-up)

Antenna detected

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

Byte sequence given in section 2.3.3.2 should be applied.

ANT_OK

I (pull-up)

Antenna not shorted

“high” = antenna has no short “low” = antenna has a short

Byte sequence given in section 2.3.3.2 should be applied.

ANT_OFF

Control signal to turn on and off the antenna supply

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

Byte sequence given in section 2.3.3.2 should be applied.

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.

Table 4: 3-pin Antenna supervisor pins

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 is not required (for example, 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 (for example, 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.11) on the I/O lines in series. Choose these components with care because they also affect the signal rise times. Alternatively, feed-through capacitors with good GND connection close to the GNSS receiver can be used (see Appendix B.12).

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 to protect against EMI. For more information, see subsection 2.14.6.3.

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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, 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 (typically 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 the TimeMark feature has to be used.

For more information about time aiding or timemark, see the u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification [3].

☞ 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 EVA-M8 data sheet [1] and the EVA8M data sheet [2], an active antenna with a good LNA inside or the mandatory LNA with passive antenna in front of EVA-8M / EVA-M8M GNSS module must have a noise figure below 1 dB. EVA-M8Q with the passive antenna an external LNA is only recommended.

The EVA-M8 series GNSS modules can receive and track multiple GNSS systems (for example, 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.

☞ 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 sheets for EVA-M8 [1] and the EVA-8M [2], see Appendix A. For EVA-M8Q with a passive antenna, an 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 (for example, 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)

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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, 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 (for example, a GSM antenna) GNSS performance can be degraded or the maximum input power of the EVA-8M / EVA-M8 series GNSS modules RF input can be exceeded. An additional SAW filter (F2) has to be placed 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.

Note 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 setup. 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 startup, the EVA-8M / EVA-M8 series GNSS module starts in safe boot mode and does not 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 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 u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification [3].

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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 input-only with an internal pull-up resistor. It must be at low level for at least 10 ms to

make sure that RESET_N is detected. Leave RESET_N open for normal operation. The RESET_N complies with the VCC_IO level and can be actively driven high.

☞ Use RESET_N 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 checklists

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 data sheets for EVA-M8 [1] and EVA-8M [2] .

 Make sure the antenna is not placed close to noisy parts of the circuitry and does not face any

noisy parts, such as micro-controller, display, etc.).

 To optimize performance in environments with out-band jamming/interference sources, use an

additional SAW filter.

☞ For more information about dealing with interference issues see the GPS Antenna Application

Note [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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Pin #

Name

I/O

Description

Remark

RF_IN

RF Input

Add external LNA and SAW if no active antenna used.

GND I Ground

Outer ground pin

Reserved

I/O

Reserved

Do not connect. Must be left open!

Reserved

I/O

Reserved

Do not connect. Must be left open!

USB_DM

I/O

USB data

Leave open if not used.

USB_DP

I/O

USB data

Leave open if not used.

VDD_USB

USB Interface power

Connect to GND if not used.

RTC_O

RTC Output

Leave open if no RTC Crystal attached.

RTC_I

RTC Input

Connect to GND if no RTC Crystal attached.

Reserved

I/O

Reserved

Do not connect. Must be left open!

Reserved

I/O

Reserved

Do not connect. Must be left open!

PIO14 / ANT_DET

Antenna detection

Leave open if not used.

PIO13 / EXTINT

External interrupt

Leave open if not used.

RESET_N

System reset

See section 2.7.

RXD / SPI MOSI

Serial interface

See section 2.2.

TXD / SPI MISO

Serial interface

See section 2.2.

Reserved

I/O

Reserved

Do not connect. Must be left open!

GND I Ground

Outer ground pin

VCC

Main supply

See section 2.1.

VCC_IO

I/O Supply

See section 2.1.

V_BCKP

Backup supply

See section 2.1.

SQI_D0

I/O

Data line 0 to external SQI flash memory or reserved configuration pin.

Leave open if not used.

SQI_CLK

I/O

Clock for external SQI flash memory or configuration pin.

Leave open if not used.

SQI_D2

I/O

Data line 2 to external SQI flash memory or reserved configuration pin.

Leave open if not used.

SQI_D1

I/O

Data line 1 to external SQI flash memory or reserved configuration pin.

Leave open if not used.

SQI_CS_N

I/O

Chip select for external SQI flash memory or configuration enable pin.

Leave open if not used.

SQI_D3

I/O

Data line 3 to external SQI flash memory or reserved configuration pin.

Leave open if not used. 28

Reserved

I/O

Reserved

Do not connect. Must be left open!

SCL / SPI CLK

Serial interface

See section 2.2.

SDA / SPI CS_N

I/O

Serial interface

See section 2.2.

 VDD_USB: Connect the USB power supply to an 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

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TIMEPULSE

Time pulse output

Leave open if not used.

D_SEL

Interface selector

See section 2.2.

SAFEBOOT_N

Used for programming the SQI flash memory and testing purposes.

Leave open if not used. 34

ANT_OK

Antenna status

Leave open if not used.

ANT_OFF

Antenna control

Leave open if not used.

Reserved

I/O

Reserved

Do not connect. Must be left open!

GND I Ground

Inner ground pin

GND I Ground

Inner ground pin

GND I Ground

Inner ground pin

GND I Ground

Inner ground pin

GND I Ground

Inner ground pin

GND I Ground

Inner ground pin

GND I Ground

Inner ground pin

Previous name

New name

V_USB

VDD_USB

RX / MOSI

RXD / SPI MOSI

TX / MISO

TXD / SPI MISO

SQI_CS

SQI_CS_N

SCL / SCK

SCL / SPI CLK

SDA / CS_N

SDA / SPI CS_N

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

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.

Table 6: EVA-M8M pin name changes

☞ For more information about pin assignment see the EVA-M8 Data sheet [1] and the EVA-8M Data

sheet [2].

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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Pin 1

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 that there is only GND around and 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

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

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☞ Consider the paste mask outline 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 customer’s specific production processes (for example, soldering.

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.

2.12 Layout design-in: Thermal management

During design-in do not place the module near sources of heating or cooling. The receiver oscillator is sensitive to sudden changes in ambient temperature which can adversely impact satellite signal tracking. Sources can include co-located power devices, cooling fans or thermal conduction via the PCB. Take into account the following questions when designing in the module.

 Is the receiver placed away from heat sources?  Is the receiver placed away from air-cooling sources?  Is the receiver shielded by a cover/case to prevent the effects of air currents and rapid

environmental temperature changes?

⚠ High temperature drift and air vents can affect the GNSS performance. For best performance,

avoid high temperature drift and air vents near the module.

2.13 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 data sheet for EVA-M8 [1] and EVA8M [2].

The EVA-M8M and EVA-M8Q GNSS modules provide flash firmware update capabilities when connecting an external SQI flash memory device. For 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.

☞ EVA-7M design which makes use of the single crystal feature cannot be migrated to EVA-M8Q.

Single crystal feature is not supported on EVA-M8Q.

☞ For an overall description of the module software operation, see the u-blox 8 / u-blox M8 Receiver

Description Including Protocol Specification [3].

☞ For migration, see the u-blox 7 to u-blox 8 / u-blox M8 software migration guide [7].

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EVA-7M

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

Pin name

Typical assignment

Pin name

Typical assignment

Remarks for migration

RF input

Add external LNA and SAW if no active antenna used

RF input

Add external LNA and SAW if no active antenna used

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

GND

Ground

GND

Ground

No difference

Reserved

Leave open.

Reserved

Leave open.

No difference

Reserved

Leave open.

Reserved

Leave open.

No difference

USB_DM

USB data

USB_DM

USB data

No difference

USB_DP

USB data

USB_DP

USB data

No difference

V_USB

USB supply

VDD_USB

USB supply

No difference

RTC_O

Leave open if no RTC crystal is attached.

RTC_O

Leave open if no RTC crystal is attached.

No difference

RTC_I

Connect to GND if no RTC crystal is attached.

RTC_I

Connect to GND if no RTC crystal is attached.

No difference 10

Reserved

Leave open.

Reserved

Leave open.

No difference

Reserved

Leave open.

Reserved

Leave open.

No difference

PIO14 / ANT_DET

Antenna detection

PIO14 / ANT_DET

Antenna detection

No difference

PIO13 / EXTINT

External interrupt

PIO13 / EXTINT

External interrupt

No difference 14

RESET_N

Leave open.

RESET_N

Leave open.

No difference

RX / MOSI

Serial interface

RXD / SPI MOSI

Serial interface

No difference

TX / MISO

Serial interface

TXD / SPI MISO

Serial interface

No difference

Reserved

Serial interface

Reserved

Leave open.

No difference

GND

Ground

GND

Ground

No difference

VCC

Main voltage supply EVA-7M 1.65 - 3.6 V

VCC

Main voltage supply EVA-8M / EVA-M8M / 1.65 - 3.6 V

No difference

EVA-M8Q 2.7 - 3.6 V

Note: EVA-M8Q has a higher voltage range.

VCC_IO

Supply voltage for PIOs EVA-7M 1.65 – 3.6 V

VCC_IO

Supply voltage for PIOs EVA-8M / EVA-M8M 1.65 - 3.6 V

No difference

EVA-M8Q 2.7 – 3.6 V

Note: EVA-M8Q has a higher voltage range.

V_BCKP

Input voltage for backup mode. EVA-7M 1.4 – 3.6 V

V_BCKP

Input voltage for backup mode EVA-8M / EVA-M8M / EVA-M8Q

1.4 – 3.6 V

No difference 22

Reserved

Leave open.

SQI_D0

Data line 0 to external SQI flash memory or reserved configuration pin.

Reserved

Leave open.

SQI_CLK

Clock for external SQI flash memory or configuration pin.

Reserved

Leave open.

SQI_D2

Data line 2 to external SQI flash memory or reserved configuration pin.

Reserved

Leave open.

SQI_D1

Data line 1 to external SQI flash memory or reserved configuration pin.

Reserved

Leave open.

SQI_CS_N

Chip select for external SQI flash memory or configuration enable pin.

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

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EVA-7M

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

Pin name

Typical assignment

Pin name

Typical assignment

Remarks for migration

Reserved

Leave open.

SQI_D3

Data line 3 to external SQI flash memory or reserved configuration pin.

Reserved

Leave open.

Reserved

Leave open.

No difference

SCL / SCK

Serial interface

SCL / SPI CLK

Serial interface

SDA / CS_N

Serial interface

SDA / SPI CS_N

Serial interface

TIMEPULSE

Time pulse output

TIMEPULSE

Time pulse output

No difference

D_SEL

Interface selector

D_SEL

Interface selector

Reserved

Leave open

SAFEBOOT_N

Used for programming the SQI flash memory and testing purposes.

Leave open if not used.

ANT_OK

Antenna status

ANT_OK

Antenna status

No difference

ANT_OFF

Antenna control

ANT_OFF

Antenna control

No difference

Reserved

Leave open.

Reserved

Leave open.

No difference

GND

Ground

GND

Ground

No difference

GND

Ground

GND

Ground

No difference

GND

Ground

GND

Ground

No difference

GND

Ground

GND

Ground

No difference

GND

Ground

GND

Ground

No difference

GND

Ground

GND

Ground

No difference

GND

Ground

GND

Ground

No difference

NEO-6M

C88-M8M

Pin name

Typical assignment

Pin name

Typical assignment

Remarks for migration

RESERVED

SAFEBOOT_N (Leave open)

RESERVED

SAFEBOOT_N (Leave open)

No difference

SS_N

SPI slave select

D_SEL

Leave open. If connected to GND SPI interface available on pins 18-21.

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

TIMEPULSE

Time pulse (1PPS)

TIMEPULSE

Time pulse (1PPS)

No difference

EXTINT0

External interrupt pin

EXTINT0

External interrupt pin

No difference

USB_DM

USB data

USB_DM

USB data

No difference

USB_DP

USB data

USB_DP

USB data

No difference

VDD_USB

USB supply

VDD_USB

USB supply

No difference

RESERVED

Pin 8 and 9 must be connected together.

RESET_N

Reset input

If pin 8 is connected to pin 9 on C88M8M, the device always runs. With NEO-6Q, if r eset input is used, it

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

2.13.2 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 the existing NEO-xM modules-based products. The C88-M8M series integrates the EVA-M8M GNSS modules into a NEO form factor adaptor board (that is, 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.

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NEO-6M

C88-M8M

Pin name

Typical assignment

Pin name

Typical assignment

Remarks for migration

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.

VCC_RF

Can be used for active antenna or external LNA supply.

VCC_RF

Can be used for active antenna or external LNA supply.

No difference

GND

No difference

RF_IN

GPS signal input

RF_IN

GPS signal input

For designs with a passive antenna directly connected to the RF_IN pin, an additional LNA in front of C88-M8M is recommended to achieve the performance values shown in the EVAM8 data sheet [1]. The noise figure of the C88-M8M is about 2 dB higher than that of NEO-6M.

GND

No difference

GND

No difference

MOSI/ CFG_COM0

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

RESERVED

Leave open.

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

MISO/ CFG_COM1

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

RESERVED

Leave open.

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

CFG_GPS0/ SCK

Power mode configuration pin / SPI clock. Leave open if not used.

RESERVED

Leave open.

Different functions. Only compatible if this pin is left open! 17

RESERVED

Leave open.

RESERVED

Leave open.

No difference

SDA

DDC data

SDA

DDC data / SPI CS_N

No difference if pin 2 is left open. If pin 2 low = SPI chip select.

SCL

DDC clock

SCL

DDC clock / SPI SCK

No difference for DDC. If pin 2 low = SPI clock.

TxD

Serial port

TxD

Serial port / SPI MISO

No difference for UART. If pin 2 low = SPI MISO.

RxD

Serial port

RxD

Serial port / SPI MOSI

No difference for UART. If pin 2 low = SPI MOSI.

V_BCKP

Backup supply voltage

V_BCKP

Backup supply voltage

No difference

VCC

Supply voltage

VCC

Supply voltage

GND

No difference

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

☞ 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 differences.

2.14 EOS/ESD/EMI precautions

When integrating GNSS receivers into wireless systems, consider electromagnetic and voltage susceptibility issues carefully. 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.

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Passive antennas

Active antennas

A B

LNA with appropriate ESD rating

RF ESD protection diode

⚠ To avoid overstress damage during production or in the field, 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].

2.14.1 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.

2.14.2 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, additional ESD measures as shown in Figure 6 can also avoid failures in the field.

Figure 6: ESD precautions

2.14.3 Electrical overstress (EOS)

Electrical overstress (EOS) usually describes situations where 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 is hard to determine whether the chip structures have been damaged by ESD or EOS.

2.14.4 EOS protection measures

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

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Passive antennas

Active antennas (without internal filter

which need the module antenna supervisor circuits)

LNA with appropriate ESD rating and maximum input power.

Figure 7: EOS and ESD precautions

2.14.5 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 (for example, pin rows)  Weakly shielded lines on PCB (for example, on top or bottom layer and especially at the border of

a PCB)

 Weak GND concept (for example, 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

☞ 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.

2.14.6 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 the Related documents section 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].

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1525 1550 1625

GPS input filter characteristics

1575 1600

-110

Jammin g signal

1525 1550 1625

Frequency [MHz]

Power [dBm]

GPS input filter characteristics

1575 1600

Interference

signal

GPS

signals

GPS Carrier

1575.4 MHz

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 cannot be achieved, for example, 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.

Increasing interference immunity

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

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, and so on.

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, for example, resistors and ferrite beads  Placement of the GNSS antenna  Adding a CDMA, GSM, WCDMA bandbass filter before handset antenna

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, and so on.

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

Figure 11: Measures against out-band interference

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 Unless there is a galvanic coupling between the local GND (i.e.

the work table) and the PCB GND, 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.

GND

Local GND

 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).

ESD

Sensitive!

RF_IN

 To prevent electrostatic discharge through the RF input, do not

touch the mounted patch antenna.

 When soldering RF connectors and patch antennas to the

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

RF_IN

ESD Safe

3 Product handling and 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 data sheets for EVA-M8 [1] and EVA-8M [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. Exercise particular care when handling patch antennas, due to the risk of electrostatic charges. In addition to standard ESD safety practices, take the following measures into account whenever handling the receiver.

⚠ 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 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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Condition

Abbreviation

Recommendation

Preheat/ soak temperature min. Preheat/ soak temperature max. Preheat/ soak time from T

smin

to T

smax

smin

smax

Ts (T

smin

to T

smax

)

150 °C 180 °C < 90 seconds

Liquidus temperature Time maintained above TL

TL tL

217°C 40 to 60 seconds

Peak package body temperature

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.

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

3.3.2 Reflow soldering

Table 9: Recommended conditions for reflow process

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) 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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The best way to test the sensitivity of a GNSS device is with the use of a multi-GNSS generator. It assures reliable 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 Product testing

4.1 Test parameters for OEM manufacturer

Because of the testing done by u-blox, an OEM manufacturer does not need to repeat firmware tests or measurements of the GNSS parameters/characteristics (for example, 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

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 device under test (DUT) and allow enough time for the acquisition.

4. Read the C/N0 value from the NMEA GSV or the UBX-NAV-SVINFO message (use, for example, 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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Parameter

Value

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

Electrical specifications

2.1

Load capacitance CL

7 pF

2.2

Equivalent series resistance RS

< 100 k

Manufacturer

Order no.

Micro Crystal

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

Manufacturer

Order no.

System supported

Comments

TDK/ EPCOS

B8401: B39162B8401P810

GPS+GLONASS

High attenuation

TDK/ EPCOS

B3913: B39162B3913U410

GPS+GLONASS+BeiDou

For automotive application

TDK/ EPCOS

B9416: B39162B9416K610

GPS

High input power

TDK/ EPCOS

B4310: B39162B4310P810

GPS+GLONASS

Compliant to the AEC-Q200 standard

TDK/ EPCOS

B4327: B39162B4327P810

GPS+GLONASS+BeiDou

Low insertion loss

TDK/ EPCOS

B9482: B39162B9482P810

GPS+GLONASS

Low insertion loss

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

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

B Component selection

This section provides information about components that are critical for the performance of the EVA8M / 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 the application. For the purpose of this document, specifications for industrial temperature range (-40 to +85 °C) are provided.

B.1 External RTC (Y1)

Table 10: RTC crystal specifications

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.

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

B.3 External LNA protection filter (F2)

Depending on the application circuit, see manufacturer data sheet for DC, ESD and RF power ratings.

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Manufacturer

Order no.

System supported

Comments

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

Manufacturer

Order no.

ST Microelectronics

USBLC6-2

Manufacturer

Order no.

Seiko Instruments Inc.

S-1206B33-I6T2G

Parameter

Value

Gain and noise Figure at1.575 GHz

1.1

Gain

> 17 dB

1.2

Noise figure

< 2 dB

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

Manufacturer

Order no.

Module

Comments

Adesto

AT25SL641

EVA-M8M

1.8 V, 64 Mbit (only 32 Mbit usable), several package/temperature options

EVA-8M

1.8 V, 64 Mbit (only 32 Mbit usable), several package/temperature options

Gigadevice

GD25Q32C

All

3 V, 32 Mbit, several package/temperature options

Table 13: Recommended parts for the LNA protection filter

B.4 USB line protection (D2)

Table 14: Recommend parts list for USB line protection

B.5 USB LDO (U1)

Table 15: Recommend parts list for USB LDO

B.6 External LNA (U1)

Table 16: External LNA specifications

Table 17: Recommend parts list for external LNA

B.7 Optional SQI Flash (U3)

UBX-16010593 - R08 Appendix Page 42 of 47 Production information

EVA-8M and EVA-M8 series - Hardware integration manual

Manufacturer

Order no.

Module

Comments

Macronix

MX25L3233F

All

3 V, 32 Mbit, several package/temperature options

Macronix

MX25V8035F

All

3 V, 8 Mbit, several package/temperature options

Macronix

MX25V1635F

All

3 V, 16 Mbit, several package/temperature options

Macronix

MX25R8035Fxxxx1

All

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

Macronix

MX25R8035Fxxxx3

All

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

Macronix

MX25R1635FxxxH1

All

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

Winbond

W25Q80DV

All

3 V, 8 Mbit, several package/temperature options

Winbond

W25Q80EW

EVA-8M and EVA-M8M

1.8 V, 8 Mbit, several package/temperature options

Winbond

W25Q16FW

EVA-8M and EVA-M8M

1.8 V, 16 Mbit, several package/temperature options Winbond

W25Q16JV

All

3 V, 16 Mbit, several package/temperature options

Winbond

W25Q16JVSNIM

All

3 V, 16 Mbit, several package/temperature options

Winbond

W25Q32JV

All

3 V, 32 Mbit, several package/temperature options

Winbond

W25Q64JV

All

3 V, 64 Mbit (only 32Mbit usable) , several package/temperature options

Manufacturer

Order no.

ON Semiconductor

ESD9R3.3ST5G

Infineon

ESD5V3U1U-02LS

Manufacturer

Order no.

Linear Technology

LT6000

Linear Technology

LT6003

Manufacturer

Order no.

Fairchild

NC7WZ07P6X

Manufacturer

Order no.

Comments

MuRata

BLM15HD102SN1

High impedance at 1.575 GHz

MuRata

BLM15HD182SN1

High impedance at 1.575 GHz

TDK

MMZ1005F121E

High impedance at 1.575 GHz

TDK

MMZ1005A121E

High impedance at 1.575 GHz

Table 18: Recommend parts list for optional SQI flash

B.8 RF ESD protection diode (D2)

Table 19: Recommend parts list for RF ESD protection diode

B.9 Operational amplifier (U6)

Table 20: Recommend parts list for operational amplifier

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

Table 21: Recommend parts list for open-drain buffer

B.11 Ferrite beads (FB1)

Table 22: Recommend parts list for ferrite beads FB1

UBX-16010593 - R08 Appendix Page 43 of 47 Production information

EVA-8M and EVA-M8 series - Hardware integration manual

Manufacturer

Order no.

Vishay

Si1016X-T1-E3 (p-channel)

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

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 which is compatible with the above-mentioned Murata inductors

Name

Use

Type / Value

RF-input DC block

COG 47P 5% 25 V

Decoupling capacitor

X7R 10N 10% 16 V

C24

Decoupling capacitor at VBUS

Depends on USB LDO (U1) specification

C23

Decoupling capacitor at VBUS

Depends on USB LDO (U1) specification

Decoupling VCC_IO at SQI flash supply pin

X5R 1U0 10% 6.3 V

Name

Use

Type / Value

USB data serial termination

27R 5% 0.1 W

USB data serial termination

27R 5% 0.1 W

Pull-up at antenna supervisor transistor

100K 5% 0.1 W

Antenna supervisor current limiter

10R 5% 0.25 W

Antenna supervisor voltage divider

560R 5% 0.1 W

Antenna supervisor voltage divider

100K 5% 0.1 W

Pull-up at LNA enable

10K 5% 0.1 W

R11

Pull-down at VDD_USB

100K 5% 0.1 W

B.12 Antenna supervisor switch transistor (T1)

Table 23: Recommend parts list for antenna supervisor switch transistor (p-channel MOSFET)

B.13 Feed-through capacitors

Table 24: Recommend parts list for feed thru capacitors

B.14 Inductor (L1)

Table 25: Recommend parts list for inductor

B.15 Standard capacitors

Table 26: Standard capacitors

B.16 Standard resistors

Table 27: Standard resistors

UBX-16010593 - R08 Appendix Page 44 of 47 Production information

EVA-8M and EVA-M8 series - Hardware integration manual

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

C Glossary

Table 28: Explanation of the abbreviations and terms used

UBX-16010593 - R08 Appendix Page 45 of 47 Production information

EVA-8M and EVA-M8 series - Hardware integration manual

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 2.13.1 (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 2.13.1. 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.

R07

20-May-2019

jesk

Updated document status on page 2.

R08

28-May-2020

mala

Added section 2.12 Layout design-in: Thermal management. Editorial changes to reflect the latest style guide changes.

Revision history

UBX-16010593 - R08 Related documents Page 46 of 47 Production information

EVA-8M and EVA-M8 series - Hardware integration manual

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

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

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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 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: info_jp@u-blox.com Support: support_jp@u-blox.com

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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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Contact

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

UBX-16010593 - R08 Contact Page 47 of 47 Production information

u-blox EVA-8M, EVA-M8 User 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

Main supply voltage (VCC)

I/O supply voltage (VCC_IO)

Backup power supply (V_BCKP)

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-pin antenna supervisor

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 checklists

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 Layout design-in: Thermal management

2.13 Migration considerations

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

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

2.14 EOS/ESD/EMI precautions

2.14.1 Electrostatic discharge (ESD)

2.14.2 ESD protection measures

2.14.3 Electrical overstress (EOS)

2.14.4 EOS protection measures

2.14.5 Electromagnetic interference (EMI)

2.14.6 Applications with cellular modules

Isolation between GNSS and GSM antenna

Increasing interference immunity

In-band interference

Out-band interference

3 Product handling and 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