NEO-M8U
u-blox M8 untethered dead reckoning module including
3D inertial sensors
Data sheet
Abstract
This data sheet describes the NEO-M8U module, which provides leading performance and
continuous navigation even with poor GNSS signal conditions. It functions independently of any
electrical connection to the car.
www.u-blox.com
UBX-15015679 - R13
C1-Public
NEO-M8U - Data sheet
Document information
Title
NEO-M8U
Subtitle
u-blox M8 untethered dead reckoning module including 3D inertial sensors
Document type
Data sheet
Document number
UBX-15015679
Revision and date
R13
Disclosure restriction
C1-Public
16-Dec-2022
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.
This document applies to the following products:
Product name
Type number
ROM/FLASH version
PCN/IN reference
Product status
NEO-M8U
NEO-M8U-0-10
Flash FW 3.01 UDR 1.00
UBX-22011767,
UBX-22039049
End of life
NEO-M8U
NEO-M8U-04B-00
FLASH FW 3.01 UDR 1.21
UBX-22011767,
UBX-22039049
End of life
NEO-M8U
NEO-M8U-05B-00
FLASH FW 3.01 UDR 1.31
UBX-22011767,
UBX-22039049
End of life
NEO-M8U
NEO-M8U-06B-00
FLASH FW 3.01 UDR 1.50
UBX-20053641,
UBX-22039049
Mass production
u-blox or third parties may hold intellectual property rights in the products, names, logos, and designs included in this
document. Copying, reproduction, or modification of this document or any part thereof is only permitted with the express
written permission of u-blox. Disclosure to third parties is permitted for clearly public documents only.
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.
UBX-15015679 - R13
C1-Public
Document information
Page 2 of 27
NEO-M8U - Data sheet
Contents
Document information ............................................................................................................................. 2
Contents ....................................................................................................................................................... 3
1
Functional description ....................................................................................................................... 5
1.1 Overview ........................................................................................................................................................ 5
1.2 Product features ......................................................................................................................................... 5
1.3 Performance................................................................................................................................................. 6
1.4 Block diagram .............................................................................................................................................. 7
1.5 Supported GNSS constellations .............................................................................................................. 7
1.5.1
GPS ........................................................................................................................................................ 8
1.5.2
GLONASS ............................................................................................................................................. 8
1.5.3
BeiDou ................................................................................................................................................... 8
1.5.4
Galileo .................................................................................................................................................... 8
1.6 Assisted GNSS (A-GNSS) .......................................................................................................................... 8
1.6.1
AssistNowTM Online............................................................................................................................ 8
1.6.2
AssistNowTM Offline ........................................................................................................................... 8
1.6.3
AssistNowTM Autonomous ............................................................................................................... 9
1.7 Augmentation systems ............................................................................................................................. 9
1.7.1
Satellite-based augmentation system (SBAS) ............................................................................ 9
1.7.2
QZSS ..................................................................................................................................................... 9
1.7.3
QZSS L1S SLAS.................................................................................................................................. 9
1.7.4
IMES ...................................................................................................................................................... 9
1.7.5
Differential GPS (D-GPS) .................................................................................................................10
1.8 Broadcast navigation data ......................................................................................................................10
1.9 Untethered dead reckoning (UDR) ........................................................................................................10
1.10 Odometer ....................................................................................................................................................11
1.11 Data logging ...............................................................................................................................................11
1.12 Geofencing..................................................................................................................................................11
1.13 Message integrity protection .................................................................................................................11
1.14 Spoofing detection ...................................................................................................................................11
1.15 TIMEPULSE ................................................................................................................................................11
1.16 Protocols and interfaces .........................................................................................................................12
1.17 Interfaces ....................................................................................................................................................12
1.17.1 UART ...................................................................................................................................................12
1.17.2 USB ......................................................................................................................................................12
1.17.3 SPI ........................................................................................................................................................12
1.17.4 Display Data Channel (DDC) ...........................................................................................................12
1.18 Clock generation........................................................................................................................................12
1.18.1 Oscillators ..........................................................................................................................................12
1.18.2 Real-time clock (RTC) and hardware backup mode...................................................................13
1.19 Power management .................................................................................................................................13
UBX-15015679 - R13
C1-Public
Contents
Page 3 of 27
NEO-M8U - Data sheet
1.19.1 Power control .....................................................................................................................................13
1.20 Antenna.......................................................................................................................................................13
2
Pin definition...................................................................................................................................... 14
2.1 Pin assignment ..........................................................................................................................................14
2.2 Pin name changes .....................................................................................................................................15
3
Configuration management.......................................................................................................... 16
3.1 Interface selection (D_SEL) ....................................................................................................................16
4
Electrical specification ................................................................................................................... 17
4.1 Absolute maximum rating.......................................................................................................................17
4.2 Operating conditions ................................................................................................................................18
4.3 Indicative current requirements ............................................................................................................18
4.4 SPI timing diagrams .................................................................................................................................19
4.4.1
Timing recommendations...............................................................................................................19
4.5 DDC timing diagrams ...............................................................................................................................19
5
Mechanical specifications ............................................................................................................. 20
6
Reliability tests and approvals..................................................................................................... 21
6.1 Reliability tests ..........................................................................................................................................21
6.2 Approvals ....................................................................................................................................................21
7
Product handling and soldering ................................................................................................... 22
7.1 Packaging ...................................................................................................................................................22
7.1.1
Reels ....................................................................................................................................................22
7.1.2
Tapes ...................................................................................................................................................22
7.2 Shipment, storage and handling ...........................................................................................................22
7.2.1
Moisture sensitivity levels ..............................................................................................................23
7.2.2
Reflow soldering ................................................................................................................................23
7.2.3
ESD handling precautions ..............................................................................................................23
8
Default messages ............................................................................................................................ 24
9
Labeling and ordering information ............................................................................................. 25
9.1 Product labeling.........................................................................................................................................25
9.2 Explanation of codes ................................................................................................................................25
9.3 Ordering codes...........................................................................................................................................25
Related documents ................................................................................................................................ 26
Revision history ....................................................................................................................................... 26
Contact....................................................................................................................................................... 27
UBX-15015679 - R13
C1-Public
Contents
Page 4 of 27
NEO-M8U - Data sheet
1
☞
Functional description
For more information about the functions, see the u-blox 8 / u-blox M8 Receiver Description
Including Protocol Specification [2].
1.1 Overview
The NEO-M8U module introduces u-blox’s untethered dead reckoning (UDR) technology, which
provides continuous navigation without requiring speed information from the vehicle. This innovative
technology brings the benefits of dead reckoning to installations previously restricted to using GNSS
alone, and significantly reduces the cost of installation for after-market dead reckoning applications.
The strength of UDR is particularly apparent under poor signal conditions, where it brings continuous
positioning in urban environments, even to devices with antennas installed within the vehicle. Useful
positioning performance is also available during complete signal loss, for example in parking garages
and short tunnels. With UDR, positioning starts as soon as power is applied to the module, before the
first GNSS fix is available.
The NEO-M8U may be installed in any position within the vehicle without configuration. In addition to
its freedom from any electrical connection to the vehicle, the on-board accelerometer and gyroscope
sensors result in a fully self-contained solution, perfect for rapid product development with reliable
and consistent performance.
The intelligent combination of GNSS and sensor measurements enables accurate, real-time
positioning at rates up to 30 Hz, as is needed for smooth and responsive interactive applications.
Native high-rate sensor data is made available to host applications such as driving behavior analysis
or accident reconstruction.
The NEO-M8U includes u-blox’s latest generation GNSS receiver, which adds Galileo to the multiconstellation reception that already includes GPS, GLONASS, BeiDou and QZSS. The module provides
high sensitivity and fast GNSS signal acquisition and tracking. UART, USB, DDC (I2C-compliant) and
SPI interface options provide flexible connectivity and enable simple integration with most u-blox
cellular modules.
u-blox M8 modules use GNSS chips qualified according to AEC-Q100 and are manufactured in ISO/TS
16949 certified sites. Qualification tests are performed as stipulated in the ISO16750 standard “Road
vehicles – Environmental conditions and testing for electrical and electronic equipment”.
1.2 Product features
For an overview of the product features, see the NEO-M8U product summary [5].
UBX-15015679 - R13
C1-Public
Functional description
Page 5 of 27
NEO-M8U - Data sheet
1.3 Performance
Parameter
Specification
Receiver type
72-channel u-blox M8 engine
GPS L1C/A, SBAS L1C/A, QZSS L1C/A, QZSS L1-SAIF, GLONASS L1OF, BeiDou B1I , Galileo
E1B/C
Accuracy of time pulse
signal
RMS
30 ns
99%
60 ns
Frequency of time pulse
signal
0.25 Hz…10 MHz
(configurable)
Operational limits 1
Dynamics
≤4g
Altitude
50,000 m
Velocity
500 m/s
Velocity accuracy 2
0.05 m/s
Heading accuracy
1 degrees
2
Position error
during GNSS loss 3
< 60 s signal loss
typ. 10% distance
travelled
Max navigation update
rate, high navigation rate
output
30 Hz
Max navigation update
rate (PVT) 4
2 Hz
Navigation latency,
high navigation rate
output
98% fix report rate under typical conditions
5
All satellites at -130 dBm, except Galileo at -127 dBm
6
Dependent on aiding data connection speed and latency
7
Demonstrated with a good external LNA
8
Configured min. CNO of 6 dB/Hz, limited by FW with min. CNO of 20 dB/Hz for best performance
9
CEP, 50%, 24 hours static, -130 dBm, > 6 SVs
10
To be confirmed when Galileo reaches full operational capability
11
CEP, 50%, 24 hours static, -130 dBm, > 6 SVs
12
CEP, 50%, 24 hours static, -130 dBm, > 6 SVs
1
2
UBX-15015679 - R13
C1-Public
Functional description
Page 6 of 27
NEO-M8U - Data sheet
1.4 Block diagram
Figure 1: NEO-M8U block diagram
1.5 Supported GNSS constellations
The NEO-M8U GNSS module is a concurrent GNSS receiver which can receive and track multiple
GNSS systems: GPS, Galileo, GLONASS and BeiDou. Owing to the dual-frequency RF front-end
architecture, either GLONASS or BeiDou can be processed concurrently with GPS and Galileo signals
providing reception of three GNSS systems. By default the M8 receivers are configured for concurrent
GPS and GLONASS, including SBAS and QZSS reception. If power consumption is a key factor, then
the receiver should be configured for a single GNSS operation using GPS, Galileo, GLONASS or BeiDou
and disabling QZSS and SBAS.
QZSS, IMES and SBAS augmentation systems share the same frequency band as GPS and can always
be processed in conjunction with GPS.
The module can be configured to receive any single GNSS constellation or within the set of permissible
combinations shown below.
GPS
Galileo
GLONASS
BeiDou
•
•
–
–
•
•
•
–
•
•
–
•
•
–
•
–
•
–
–
•
–
•
•
–
–
•
–
•
–
–
•
•
Table 2 Permissible GNSS combinations (• = enabled)
☞
☞
The augmentation systems SBAS and QZSS can be enabled only if GPS operation is configured.
Galileo is not enabled as a default configuration.
UBX-15015679 - R13
C1-Public
Functional description
Page 7 of 27
NEO-M8U - Data sheet
1.5.1 GPS
The NEO-M8U positioning module is designed to receive and track the L1C/A signals provided at
1575.42 MHz by the global positioning system (GPS). The NEO-M8U can receive and process GPS
concurrently with Galileo and with either GLONASS or BeiDou.
1.5.2 GLONASS
The NEO-M8U positioning module can receive and process GLONASS concurrently with GPS and
Galileo or BeiDou. The Russian GLONASS satellite system is a fully deployed alternative to the USbased global positioning system (GPS). The NEO-M8U module is designed to receive and track the
L1OF signals GLONASS provides around 1602 MHz. The ability to receive and track GLONASS L1OF
satellite signals allows design of GLONASS receivers where required by regulations.
1.5.3 BeiDou
The NEO-M8U positioning module can receive and process BeiDou concurrently with GPS and Galileo
together or with GLONASS. The NEO-M8U module is designed to receive and track the B1 signals
provided at 1561.098 MHz by the BeiDou Navigation Satellite System. The ability to receive and track
BeiDou B1 satellite signals in conjunction with GPS results in higher coverage, improved reliability and
better accuracy. Global coverage is scheduled for 2020.
1.5.4 Galileo
The NEO-M8U positioning module can receive and track the E1-B/C signals centered on the GPS L1
frequency band. GPS and Galileo signals can be processed concurrently together with either BeiDou
or GLONASS signals, enhancing coverage, reliability and accuracy. The SAR return link message
(RLM) parameters for both short and long versions are decoded by the receiver and made available to
users via UBX proprietary messages.
☞
Galileo has been implemented according to ICD release 1.2 (November 2015) and verified with live
signals from the Galileo in-orbit validation campaign. Since the Galileo satellite system has not yet
reached Initial (IOC) nor Full Operational Capability (FOC), changes to the Galileo signal
specification (OS SIS ICD) remain theoretically possible.
☞
Galileo reception is by default disabled, but can be enabled by sending a configuration message
(UBX-CFG-GNSS) to the receiver.
1.6 Assisted GNSS (A-GNSS)
Supply of aiding information, such as ephemeris, almanac, approximate position and time, will reduce
the time-to-first-fix significantly and improve the acquisition sensitivity. The NEO-M8U product
supports the u-blox AssistNow Online and AssistNow Offline A-GNSS services, supports AssistNow
Autonomous, and is OMA SUPL-compliant.
1.6.1 AssistNowTM Online
With AssistNow Online, an internet-connected GNSS device downloads assistance data from u-blox’s
AssistNow Online Service at system start-up. AssistNow Online is network-operator independent and
globally available. Devices can be configured to request only ephemeris data for those satellites
currently visible at their location, thus minimizing the amount of data transferred.
1.6.2 AssistNowTM Offline
With AssistNow Offline, users download u-blox’s long-term orbit data from the internet at their
convenience. The orbit data can be stored in the NEO-M8U GNSS receiver’s SQI flash memory. Thus
the service requires no connectivity at system start-up, enabling a position fix within seconds, even
when no network is available. AssistNow Offline offers augmentation for up to 35 days.
UBX-15015679 - R13
C1-Public
Functional description
Page 8 of 27
NEO-M8U - Data sheet
1.6.3 AssistNowTM Autonomous
AssistNow Autonomous provides aiding information without the need for a host or external network
connection. Based on previous broadcast satellite ephemeris data downloaded to and stored by the
GNSS receiver, AssistNow Autonomous automatically generates accurate satellite orbital data
(“AssistNow Autonomous data”) that is usable for future GNSS position fixes. The concept capitalizes
on the periodic nature of GNSS satellites: their position in the sky is basically repeated every 24 hours.
By capturing strategic ephemeris data at specific times over several days, the receiver can predict
accurate satellite ephemeris for up to six days after initial reception.
u-blox’s AssistNow Autonomous benefits are:
•
•
•
•
☞
Faster fix in situations where GNSS satellite signals are weak
No connectivity required
Compatible with AssistNow Online and Offline (can work stand-alone, or in tandem with these
services)
No integration effort; calculations are done in the background, transparent to the user.
For more details see the u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification
[2] and the MGA Services User Guide [4].
1.7 Augmentation systems
1.7.1 Satellite-based augmentation system (SBAS)
The NEO-M8U positioning module supports SBAS. These systems supplement GPS data with
additional GPS augmentation data within defined service areas. The systems broadcast
augmentation data via satellite and this information can be used by GNSS receivers to improve the
resulting precision. In some cases SBAS satellites can be used as additional satellites for ranging
(navigation), further enhancing precision and availability.
1.7.2 QZSS
The Quasi-Zenith Satellite System (QZSS) is a regional navigation satellite system that transmits
additional GPS L1 C/A signals for the Pacific region covering Japan and Australia. NEO-M8N
positioning module is able to receive and track these signals concurrently with GPS signals, resulting
in better availability especially under challenging signal conditions, for example, in urban canyons.
1.7.3 QZSS L1S SLAS
QZSS SLAS (sub-meter level augmentation service) is an augmentation technology which provides
correction data for pseudoranges of GPS and QZSS satellites. With the QZSS SLAS enabled, u-blox
receivers autonomously select the most suitable ground monitoring stations (GMS) based on the
user’s location. The correction stream of this GMS will then be applied to the measurements in order
to improve the position accuracy.
1.7.4 IMES
The Japanese indoor messaging system (IMES) is used for indoor position reporting using low-power
transmitters which broadcast a GPS–like signal. NEO-M8N module can be configured to receive and
demodulate the signal to provide an in-door location estimate.
☞
☞
This service is authorized and available only in Japan.
IMES reception is disabled by default.
UBX-15015679 - R13
C1-Public
Functional description
Page 9 of 27
NEO-M8U - Data sheet
1.7.5 Differential GPS (D-GPS)
The use of differential-GPS data improves GPS position accuracy using real time data from a nearby
reference receiver or network. The NEO-M8U receiver supports D-GPS only with dead reckoning
disabled (using message UBX-CFG-NAVX5). D-GPS starts on receipt of valid data according RTCM
10402.3: “RECOMMENDED STANDARDS FOR DIFFERENTIAL GNSS”. RTCM cannot be used
together with SBAS or dead reckoning and is applicable only to GPS signals in the NEO-M8U. The
RTCM implementation supports the following RTCM 2.3 messages:
Message type
Description
1
Differential GPS corrections
2
Delta differential GPS corrections
3
GPS reference station parameters
9
GPS partial correction set
Table 3: Supported RTCM 2.3 messages
1.8 Broadcast navigation data
The NEO-M8U can output all the GNSS broadcast data upon reception from tracked satellites. This
includes all the supported GNSS signals plus the augmentation services SBAS, QZSS and IMES.
The L1- SAIF signal provided by QZSS can be enabled for reception via a GNSS configuration
message.
1.9 Untethered dead reckoning (UDR)
u-blox’s proprietary untethered dead reckoning (UDR) solution uses an inertial measurement unit
(IMU) included within the module. IMU data and GNSS signals are processed together, achieving
accurate and continuous positioning in GNSS-hostile environments (for example, urban canyons) and
useful positioning even in case of complete GNSS signal absence (for example, tunnels and parking
garages).
The NEO-M8U combines GNSS and IMU measurements and calculates position solutions at rates of
up to 2 Hz. These solutions are reported in standard NMEA, UBX-NAV-PVT and related messages. A
new High navigation rate output message (UBX-HNR-PVT) extends these results with IMU-only data
to deliver accurate, low-latency position solutions at rates of up to 30 Hz.
Dead reckoning allows navigation to commence as soon as power is applied to the module (that is,
before a GNSS fix has been established) and given all of the following conditions:
•
•
•
☞
The vehicle has not been moved without power applied to the module.
At least a dead-reckoning fix was available when the vehicle was last used.
A back-up supply has been available for the module since the vehicle was last used.
The save-on-shutdown feature can be used in case no back-up supply is available. All information
necessary will be saved to flash and read from the flash upon restart. For more details, see the ublox 8 / u-blox M8 Receiver Description / Protocol Specification [2].
For post-processing applications sensor data is available from messages UBX-ESF-MEAS and UBXESF-RAW (high rate). Each message includes the time of measurement.
UBX-15015679 - R13
C1-Public
Functional description
Page 10 of 27
NEO-M8U - Data sheet
1.10 Odometer
The odometer provides information on travelled ground distance (in meters) using position and
velocity measurements from the combined GNSS/DR navigation solution. For each computed
traveled distance since the last odometer reset, the odometer estimates a 1-sigma accuracy value.
The total cumulative ground distance is maintained and saved in the BBR memory.
☞
The odometer feature is disabled by default.
1.11 Data logging
The u-blox NEO-M8U receiver can be used in data logging applications. The data logging feature
enables continuous storage of position, velocity and time information to an onboard SQI flash
memory. It can also log the distance reported by the odometer. The information can be downloaded
later from the receiver for further analysis, or for conversion to a mapping tool.
1.12 Geofencing
The u-blox NEO-M8U module supports up to four circular geofencing areas defined on the Earth’s
surface using a 2D model. Geofencing is active when at least one geofence is defined, the current
status can be found by polling the receiver. A GPIO pin can be nominated to indicate status to, for
example, wake up a host on activation.
1.13 Message integrity protection
The NEO-M8U provides a function to detect third party interference with the UBX message stream
sent from receiver to host. The security mechanism “signs” nominated messages via a subsequent
UBX message. This message signature is then compared with a signature generated by the host to
determine if the message data has been altered.
1.14 Spoofing detection
Spoofing means that a malicious third party tries to control the reported position via a fake GNSS
broadcast signal. This may result in reporting incorrect position, velocity or time. To combat this, the
NEO-M8U module includes spoofing detection measures to alert the host when signals appear to be
suspicious. The receiver combines a number of checks on the received signals looking for
inconsistencies across several parameters.
1.15 TIMEPULSE
A configurable time pulse signal is available with the NEO-M8U module.
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.
☞
The NEO-M8U time-pulse output is configured using messages for “TIMEPULSE2.” This pin has a
secondary function during start-up (initiation of “SAFEBOOT” mode for firmware recovery) and
should not normally be held LOW during start-up.
UBX-15015679 - R13
C1-Public
Functional description
Page 11 of 27
NEO-M8U - Data sheet
1.16 Protocols and interfaces
Protocol
Type
NMEA 0183 V4.0 (V2.1, V2.3 and V4.1 configurable)
Input/output, ASCII
UBX
Input/output, binary, u-blox proprietary
RTCM
Input, messages 1, 2, 3, 9
Table 4: Available protocols
All protocols are available on UART, USB, DDC (I2C compliant) and SPI. For specification of the various
protocols see the u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification [2].
1.17 Interfaces
A number of interfaces are provided for data communication. The embedded firmware uses these
interfaces according to their respective protocol specifications.
1.17.1 UART
The NEO-M8U module includes one UART interface, which can be used for communication to a host.
It supports configurable baud rates. For supported baud rates see the u-blox 8 / u-blox M8 Receiver
Description Including Protocol Specification [2].
☞
Designs must allow access to the UART and the SAFEBOOT_N function pin for future service,
updates and reconfiguration.
1.17.2 USB
A USB interface, which is compatible to USB version 2.0 FS (Full Speed, 12 Mbit/s), can be used for
communication as an alternative to the UART. The pull-up resistor on pin USB_DP is integrated to
signal a full-speed device to the host. The VDD_USB pin supplies the USB interface. The u-blox USB
(CDC-ACM) driver supports Windows Vista plus Windows 7 and 8 operating systems. A separate
driver (CDC-ACM) is not required for Windows 10 which has a built-in USB-serial driver. However,
plugging initially into an internet-connected Windows 10 PC will download the u-blox combined sensor
and VCP driver package.
USB drivers can be down-loaded from the u-blox web site, www.u-blox.com.
1.17.3 SPI
The SPI interface is designed to allow communication to a host CPU. The interface can be operated in
slave mode only. The maximum transfer rate using SPI is 125 kB/s and the maximum SPI clock
frequency is 5.5 MHz, see Figure 3. Note that SPI is not available in the default configuration because
its pins are shared with the UART and DDC interfaces. The SPI interface can be enabled by connecting
D_SEL (Pin 2) to ground (see section 3.1).
1.17.4 Display Data Channel (DDC)
An I2C-compliant DDC interface is available for communication with an external host CPU or u-blox
cellular modules. The interface can be operated in slave mode only. The DDC protocol and electrical
interface are fully compatible with Fast-Mode of the I2C industry standard. Since the maximum SCL
clock frequency is 400 kHz, the maximum transfer rate is 400 kb/s.
1.18 Clock generation
1.18.1 Oscillators
The NEO-M8U GNSS module uses a crystal-based oscillator.
UBX-15015679 - R13
C1-Public
Functional description
Page 12 of 27
NEO-M8U - Data sheet
1.18.2 Real-time clock (RTC) and hardware backup mode
The RTC can be maintained by a secondary 32-kHz oscillator using an RTC crystal. If the main supply
voltage is removed, a battery connected to V_BCKP allows the RTC to continue to run with very low
power consumption. The same supply also maintains a static back-up memory for current
configuration information, recent ephemeris, location and auxiliary data necessary to ensure the
fastest re-acquisition when the primary power supply is restored.
☞
Dead reckoning before the first GNSS fix requires that the RTC has been enabled and powered
since the previous fix.
1.19 Power management
u-blox M8 technology offers a power-optimized architecture with built-in autonomous power saving
functions to minimize power consumption at any given time. In addition, a high-efficiency DC/DC
converter is integrated for lower power consumption and reduced dissipation.
1.19.1 Power control
A separate battery backup voltage may be applied to the module to retain the current state of the
receiver and sustain a low-power real time clock (RTC) while the main supply is removed. This enables
fast acquisition and navigation based on dead reckoning before the first GNSS-based fix.
Alternatively, a configuration command (UBX-CFG-PWR) can be issued to stop the receiver in a similar
way to hardware backup mode (see section 1.18.2) while the main supply remains active. This mode
is referred to as software backup mode; current consumption in this mode is slightly higher than in
hardware backup mode. The receiver will then restart on the next edge received at its UART interface
(there will be a delay before any communication is possible).
See Table 10 for current consumption in backup mode.
1.20 Antenna
To achieve the best performance, u-blox recommends using an active antenna 13 or an external LNA
with this module.
Parameter
Specification
Antenna Type
Active Antenna Recommendations
Active or passive antenna
Minimum gain
Maximum gain
Maximum noise figure
15 dB (to compensate signal loss in RF cable)
50 dB 14
1.5 dB
Table 5: Antenna specifications for the NEO-M8U module
The antenna system should include filtering to ensure adequate protection from nearby transmitters.
Select antennas placed closed to cellular or Wi-Fi transmitting antennas carefully.
☞
13
14
For guidance on antenna selection see the NEO-M8U Hardware integration manual [1].
For information on using active antennas with NEO-M8U modules, see the NEO-M8U Hardware Integration Manual [1].
Gain above 20 dB should be avoided unless interference in the band 1463 MHz to 1710 MHz is adequately controlled.
UBX-15015679 - R13
C1-Public
Functional description
Page 13 of 27
NEO-M8U - Data sheet
2
Pin definition
2.1 Pin assignment
Figure 2: Pin assignment
No.
Name
I/O
Description
1
SAFEBOOT_N
I
SAFEBOOT_N, test-point for service use (leave OPEN)
2
D_SEL
I
Interface select
3
TIMEPULSE
I/O
Time pulse (disabled by default), do not pull low during reset
Note: configured using TIMEPULSE2 messages (see section 1.15)
4
EXTINT
I
Externa interrupt pin
5
USB_DM
I/O
USB data
6
USB_DP
I/O
USB data
7
VDD_USB
I
USB supply
8
RESET_N
I
RESET_N
9
VCC_RF
O
Output voltage RF section
10
GND
I
Ground
11
RF_IN
I
GNSS signal input
12
GND
I
Ground
13
GND
I
Ground
14
LNA_EN
O
Antenna control
15
Reserved
-
Reserved
16
Reserved
-
Reserved
17
Reserved
-
Reserved
18
SDA / SPI CS_N
I/O
DDC data if D_SEL =1 (or open) / SPI chip select if D_SEL = 0
19
SCL / SPI CLK
I/O
DDC clock if D_SEL =1(or open) / SPI clock if D_SEL = 0
20
TXD / SPI MISO
O
Serial port if D_SEL =1(or open) / SPI MISO if D_SEL = 0
21
RXD / SPI MOSI
I
Serial port if D_SEL =1(or open) / SPI MOSI if D_SEL = 0
22
V_BCKP
I
Backup voltage supply
23
VCC
I
Supply voltage
24
GND
I
Ground
Table 6: Pinout of NEO-M8U
UBX-15015679 - R13
C1-Public
Pin definition
Page 14 of 27
NEO-M8U - Data sheet
☞
Pins designated Reserved should not be used. For more information about pinouts see the NEOM8U Hardware integration manual [1].
2.2 Pin name changes
Selected 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 the pins that have a changed name along with their old and new
names.
No
Previous name
New name
14
ANT_ON
LNA_EN
20
TxD
SPI MISO
TXD /
SPI MISO
21
RxD
SPI MOSI
RXD /
SPI MOSI
Table 7: Pin name changes
UBX-15015679 - R13
C1-Public
Pin definition
Page 15 of 27
NEO-M8U - Data sheet
3
Configuration management
Configuration settings can be modified with UBX configuration messages. The modified settings
remain effective until power-down or reset. Settings can also be saved in the battery-backed RAM,
flash or both using the UBX-CFG-CFG message. If settings have been stored in the battery-backed
RAM then the modified configuration will be retained as long as the backup battery supply is not
interrupted. Settings stored in the flash memory will remain effective even after power-down and do
not require backup battery supply.
3.1 Interface selection (D_SEL)
At startup Pin 2 (D_SEL) determines which data interfaces are used for communication. If D_SEL is
set high or left open, UART and DDC become available. If D_SEL is set low, that is, connected to
ground, the NEO-M8U module can communicate to a host via SPI.
PIN #
D_SEL=”1”
(left open)
D_SEL =”0”
(connected to GND)
20
UART TX
SPI MISO
21
UART RX
SPI MOSI
19
DDC SCL
SPI CLK
18
DDC SDA
SPI CS_N
Table 8: Data interface selection by D_SEL
UBX-15015679 - R13
C1-Public
Configuration management
Page 16 of 27
NEO-M8U - Data sheet
4
Electrical specification
☞
The limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134).
Stress above one or more of the limiting values may cause permanent damage to the device. These
are stress ratings only and operation of the device at these or at any other conditions above those
given in the characteristics sections of the specification is not implied. Exposure to these limits
for extended periods may affect device reliability.
☞
Where application information is given, it is advisory only and does not form part of the
specification. For more information see the NEO-M8U Hardware integration manual [1].
4.1 Absolute maximum rating
Parameter
Symbol
Power supply voltage
Backup battery voltage
Condition
Min
Max
Units
VCC
–0.5
3.6
V
V_BCKP
–0.5
3.6
V
USB supply voltage
VDD_USB
–0.5
3.6
V
Input pin applied DC voltage
Vin
–0.5
VCC+0.5
V
Vin_usb
–0.5
VDD_USB
V
Vrfin
0
6
V
DC current through any digital I/O
pin (except supplies)
Ipin
10
mA
VCC_RF output current
ICC_RF
100
mA
Input power at RF_IN
Prfin
15
dBm
Storage temperature
Tstg
85
°C
source impedance =
50 Ω, continuous wave
–40
Table 9: Absolute maximum ratings
⚠
Stressing the device beyond the “Absolute Maximum Ratings” may cause permanent damage.
These are stress ratings only. The product is not protected against overvoltage or reversed
voltages. If necessary, voltage spikes exceeding the power supply voltage specification, given in
Table 9, must be limited to values within the specified boundaries by using appropriate protection
diodes.
UBX-15015679 - R13
C1-Public
Electrical specification
Page 17 of 27
NEO-M8U - Data sheet
4.2 Operating conditions
☞
All specifications are at an ambient temperature of 25 °C. Extreme operating temperatures can
significantly impact the specification values. Applications operating near the temperature limits
should be tested to ensure the specification.
Parameter
Symbol
Min
Typical
Max
Units
Power supply voltage
VCC
2.7
3.0
3.6
V
Supply voltage USB
VDD_USB
3.0
3.3
3.6
V
Backup battery voltage
V_BCKP
1.4
Backup battery current
I_BCKP
15
µA
V_BCKP = 1.8 V, VCC = 0 V
SW backup current
I_SWBCKP
30
µA
VCC = 3 V
Input pin voltage range
Vin
3.6
Condition
V
0
VCC
V
Digital IO Pin Low level input voltage Vil
0
0.2*VCC
V
Digital IO Pin High level input
voltage
Vih
0.7*VCC
VCC
V
Digital IO Pin Low level output
voltage
Vol
0.4
V
Iol = 4 mA
Digital IO Pin High level output
voltage
Voh
V
Ioh = 4 mA
Pull-up resistor for RESET_N
Rpu
USB_DM, USB_DP
VinU
VCC_RF voltage
VCC_RF
VCC_RF output current
ICC_RF
Receiver Chain Noise Figure 15
NFtot
Operating temperature
Topr
VCC–0.4
11
kΩ
Compatible with USB with 27 Ω series resistance
VCC–0.1
V
50
3
mA
dB
–40
85
°C
Table 10: Operating conditions
☞
Operation beyond the specified operating conditions can affect device reliability.
4.3 Indicative current requirements
Table 11 lists examples of the total system supply current for a possible application.
☞
Values in Table 11 are provided for customer information only as an example of typical power
requirements. Values are characterized on samples, actual power requirements can vary
depending on the FW version used, external circuitry, number of SVs tracked, signal strength, type
of start as well as time, duration and conditions of test.
Parameter
Max supply current
Symbol
Typ.
GPS & GLONASS
GPS / QZSS / SBAS
29
23
Iccp
16
Average supply current
Typ.
17, 18
Icc
Max
Units
67
mA
mA
Condition
Estimated at 3 V
Table 11: Indicative power requirements at 3.0 V
☞
For more power requirements information, see the NEO-M8U Hardware integration manual [1].
Only valid for the GPS band
Use this figure to determine maximum current capability of power supply. Measurement of this parameter with 1 Hz
bandwidth.
17
Acquisition and tracking use this figure to determine required battery capacity
18
Simulated GNSS constellation using power levels of -130 dBm. VCC = 3.0 V
15
16
UBX-15015679 - R13
C1-Public
Electrical specification
Page 18 of 27
NEO-M8U - Data sheet
4.4 SPI timing diagrams
To avoid incorrect operation of the SPI, the user needs to comply with certain timing conditions. The
following signals need to be considered for timing constraints:
Symbol
Description
SPI CS_N (SS_N)
Slave select signal
SPI CLK (SCK)
Slave clock signal
Table 12: Symbol description
Figure 3: SPI timing diagram
4.4.1 Timing recommendations
The recommendations in Table 13 are based on a firmware running from flash memory.
Parameter
Description
Recommendation
tINIT
Initialization time
>10 µs
tDES
Deselect time
1 ms
tbit
Minimum bit time
180 ns (5.5 MHz max bit frequency)
tbyte
Minimum byte period
8 µs (125 kHz max byte frequency)
Table 13: SPI timing recommendations
☞
The values in Table 13 result from the requirement of an error-free transmission. By allowing just
a few errors and disabling the glitch filter, the bit rate can be increased considerably.
4.5 DDC timing diagrams
The DDC interface is I2C Fast Mode compliant. For timing parameters consult the I2C standard.
☞
The maximum bit rate is 400 kb/s. The interface stretches the clock when slowed down when
serving interrupts, so real bit rates may be slightly lower.
UBX-15015679 - R13
C1-Public
Electrical specification
Page 19 of 27
NEO-M8U - Data sheet
5
Mechanical specifications
Figure 4 NEO M8U mechanical drawing
Symbol
Min. [mm]
Typ. [mm]
Max. [mm]
A
15.9
16.0
16.1
B
12.1
12.2
12.3
C
2.2
2.4
2.6
D
0.9
1.0
1.1
E
1.0
1.1
1.2
F
2.9
3.0
3.1
G
0.9
1.0
1.1
H
-
0.82
-
K
0.7
0.8
0.9
M
0.8
0.9
1.0
N
0.4
0.5
0.6
P*
0.0
-
0.5
Weight
The de-paneling residual tabs may be on either side (not both).
1.6 g
Table 14 NEO M8U mechanical dimensions
☞
The mechanical picture of the de-paneling residual tabs (P*) is an approximate representation. The
shape and position of the residual tab may vary.
☞
When designing the component keep-out area, note that the de-paneling residual tabs can be on
either side of the module (not both).
☞
For information about the paste mask and footprint, see the NEO-M8U Hardware integration
manual [1].
UBX-15015679 - R13
C1-Public
Mechanical specifications
Page 20 of 27
NEO-M8U - Data sheet
6
Reliability tests and approvals
6.1 Reliability tests
☞
The NEO-M8U module is based on AEC-Q100 qualified GNSS chips.
Tests for product family qualifications are according to ISO 16750 "Road vehicles – environmental
conditions and testing for electrical and electronic equipment”, and appropriate standards.
6.2 Approvals
Products marked with this lead-free symbol on the product label comply with
Directive 2002/95/EC and Directive 2011/65/EU of the European Parliament and
the Council on the Restriction of Use of certain Hazardous Substances in
Electrical and Electronic Equipment (RoHS).
All u-blox M8 GNSS modules are RoHS-compliant.
UBX-15015679 - R13
C1-Public
Reliability tests and approvals
Page 21 of 27
NEO-M8U - Data sheet
7
Product handling and soldering
7.1 Packaging
To enable efficient production, production lot set-up and tear-down, the NEO-M8U GNSS modules are
delivered as hermetically sealed, reeled tapes. For more information see the u-blox Package
Information Guide [3].
7.1.1 Reels
The NEO-M8U GNSS modules are deliverable in quantities of 250 pcs on a reel. The NEO-M8U
receivers are shipped on reel type B, as specified in the u-blox Package Information Guide [3].
7.1.2 Tapes
The dimensions and orientations of the tapes for NEO-M8U GNSS modules are specified in Figure 5.
Figure 5: Dimensions and orientation for NEO-M8U modules on tape
7.2 Shipment, storage and handling
For important information regarding shipment, storage and handling see the u-blox Package
Information Guide [3].
UBX-15015679 - R13
C1-Public
Product handling and soldering
Page 22 of 27
NEO-M8U - Data sheet
7.2.1 Moisture sensitivity levels
The moisture sensitivity level (MSL) relates to the packaging and handling precautions required. The
NEO-M8U modules are rated at MSL level 4.
☞
☞
For MSL standard see IPC/JEDEC J-STD-020, which can be downloaded from www.jedec.org.
For more information regarding MSL see the u-blox Package Information Guide [3].
7.2.2 Reflow soldering
Reflow profiles are to be selected according to u-blox recommendations (see the NEO-M8U Hardware
integration manual [1]).
7.2.3 ESD handling precautions
⚠
NEO-M8U modules are Electrostatic Sensitive Devices (ESD). Observe precautions for handling!
Failure to observe these precautions can result in severe damage to the GNSS receiver!
GNSS receivers are Electrostatic Sensitive Devices (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:
•
•
•
•
•
Unless there is a galvanic coupling between
the local GND (that is, the work desk) and the
PCB GND, the first point of contact when
handling the PCB must always be between
the local GND and PCB GND.
Before mounting an antenna patch, connect
ground of the device.
When handling the RF pin, do not come into
contact with any charged capacitors and be
careful when contacting materials that can
develop charges (such as patch antenna
~10 pF, coax cable ~50-80 pF/m, soldering
iron).
To prevent electrostatic discharge through
the RF input, do not touch any exposed
antenna area. If there is any risk that such
exposed antenna area is touched in a nonESD protected work area, implement proper
ESD protection measures in the design.
When soldering RF connectors and patch
antennas to the receiver’s RF pin, make sure
to use an ESD safe soldering iron (tip).
UBX-15015679 - R13
C1-Public
Product handling and soldering
Page 23 of 27
NEO-M8U - Data sheet
8
Default messages
Interface
Settings
UART Output
9600 baud, 8 bits, no parity bit, 1 stop bit.
Configured to transmit both NMEA and UBX protocols, but only the following NMEA (and no
UBX) messages have been activated at start-up:
GGA, GLL, GSA, GSV, RMC, VTG, TXT.
USB Output
Configured to transmit both NMEA and UBX protocols, but only the following NMEA (and no
UBX) messages have been activated at start-up:
GGA, GLL, GSA, GSV, RMC, VTG, TXT.
USB power mode: Bus powered.
UART Input
9600 baud, 8 bits, no parity bit, 1 stop bit, Autobauding disabled.
Automatically accepts following protocols without need of explicit configuration:
UBX, NMEA, RTCM.
The GNSS receiver supports interleaved UBX and NMEA messages.
USB Input
Automatically accepts following protocols without need of explicit configuration:
UBX, NMEA.
The GPS receiver supports interleaved UBX and NMEA messages.
USB power mode: Bus powered.
DDC
Fully compatible with the I2C industry standard, available for communication with an external
host CPU or u-blox cellular modules, operated in slave mode only. Default messages activated.
NMEA and UBX are enabled as input messages, only NMEA as output messages.
Maximum bit rate 400 kb/s.
SPI
Allow communication to a host CPU, operated in slave mode only. Default messages activated.
SPI is not available in the default configuration.
TIMEPULSE
Disabled
Table 15: Default messages
☞
Refer to the u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification [2] for
information about further settings.
UBX-15015679 - R13
C1-Public
Default messages
Page 24 of 27
NEO-M8U - Data sheet
9
Labeling and ordering information
9.1 Product labeling
The labeling of u-blox M8 GNSS modules includes important product information. The location of the
NEO-M8U product type number is shown in Figure 6.
Figure 6: Location of product type number on the u-blox NEO-M8U module label
9.2 Explanation of codes
Three different product code formats are used. The Product Name is used in documentation such as
this data sheet and identifies all u-blox M8 products, independent of packaging and quality grade. The
Ordering Code includes options and quality, while the Type Number includes the hardware and
firmware versions. Table 16 shows the structure of these three different formats.
Format
Structure
Product Name
PPP-TGV
Ordering Code
PPP-TGV-N
Type Number
PPP-TGV-N-XX
Table 16: Product code formats
The parts of the product code are explained in Table 17.
Code
Meaning
Example
PPP
Product Family
NEO
TG
Platform
M8 = u-blox M8
V
Variant
Function set (A-Z), T = Timing, L = ADR, U = UDR, etc.
N
Option / Quality Grade Describes standardized functional element or quality grade
0 = Default variant, A = Automotive
XX
Product Detail
Describes product details or options such as hard- and software revision, cable length,
etc.
Table 17: Part identification code
9.3 Ordering codes
Ordering no.
Product
NEO-M8U-05B
u-blox M8 GNSS LCC module untethered dead reckoning and on-board sensors, 12.2 x 16 mm, 250
pcs/reel
Table 18: Product ordering codes for NEO-M8U module
☞
Product changes affecting form, fit or function are documented by u-blox. For a list of Product
Change Notifications (PCNs) see our website.
UBX-15015679 - R13
C1-Public
Labeling and ordering information
Page 25 of 27
NEO-M8U - Data sheet
Related documents
[1]
[2]
[3]
[4]
[5]
☞
NEO-M8U Hardware integration manual, UBX-15016700
u-blox 8 / u-blox M8 Receiver Description including Protocol Specification, UBX 13003221
u-blox Package Information Guide, UBX-14001652
MGA Services User guide, UBX-13004360
NEO-M8U Product summary, UBX-15013483
For regular updates to u-blox documentation and to receive product change notifications, register
on our homepage (www.u-blox.com).
Revision history
Revision
Date
Name
Comments
R01
17-Feb-2016
amil
Objective Specification
R02
01-Jun-2016
ghun/amil
Advance Information
Updated Section 2 for Pin name changes, Section 4.1, Section 4.3, Section
4.4 SPI Timing, Figure 1, Figure 2, and Section 1.3.
R03
27-Jun-2016
njaf
Early Product Information
R04
20-Sep-2016
njaf
Production Information
R05
02-Oct-2018
pmcm, njaf
Changed the firmware version (page 2). Updated Mechanical specifications
(section 5).
R06
15-Feb-2019
mawa
Changed ordering code to -04B
R07
20-Mar-2020
ssid
Advance information – For NEO-M8U-05B with UDR 1.31 – Sensitivity
numbers revised
R08
22-Jun-2020
mala
Early production information.
Added information on NEO-M8L, NEO-M8U information note in Document
information and Related documents.
Added new disclosure restriction: C1-Public
R09
26-Nov-2020
ssid
Block diagram update
R10
12-Feb-2021
njaf
Firmware version and new type number added on page 2.
R11
22-Mar-2021
njaf
Product status updated to Initial production for NEO-M8U-06B-00 on page 2.
R12
25-Aug-2022
njaf
Product status updated to Mass production for NEO-M8U-06B-00 and to
end-of-life for the others on page 2.
R13
16-Dec-2022
skar
Chapter Mechanical specifications updated with information on de-paneling
residual tabs
UBX-15015679 - R13
C1-Public
Related documents
Page 26 of 27
NEO-M8U - Data sheet
Contact
u-blox AG
Address:
Zürcherstrasse 68
8800 Thalwil
Switzerland
For further support and contact information, visit us at www.u-blox.com/support.
UBX-15015679 - R13
C1-Public
Contact
Page 27 of 27
工商网监
湘ICP备2023018690号
