Ublox NEO-6, MAX-6, LEA-6 Integration Manual
Abstract
This document describes the features and specifications of the cost
effective and high-performance LEA-6, NEO-6 and MAX-6 GPS and
GPS/GLONASS/QZSS modules featuring the u-blox 6 positioning
engine.
These compact, easy to integrate stand-alone positioning modules
combine exceptional performance with highly flexible power,
design, and connectivity options. Their compact form factors and
SMT pads allow fully automated assembly with standard pick &
place and reflow soldering equipment for cost-efficient, highvolume production enabling short time-to-market.
www.u-blox.com
UBX-14054794 - R15
LEA-6 / NEO-6 / MAX-6
u-blox 6 GLONASS, GPS & QZSS modules
Hardware Integration Manual
LEA-6 / NEO-6 / MAX-6 - Hardware Integration Manual
Document Information
Title
LEA-6 / NEO-6 / MAX-6
Subtitle
u-blox 6 GLONASS, GPS & QZSS modules
Document type
Hardware Integration Manual
Document number
UBX-14054794
Revision and Date
R15
26-Sep-2017
Document status
Production Information
Document status explanation
Objective Specification
Document contains target values. Revised and supplementary data will be published later.
Advance Information
Document contains data based on early testing. Revised and supplementary data will be published later.
Early Production Information
Document contains data from product verification. Revised and supplementary data may be published later.
Production Information
Document contains the final product specification.
European Union regulatory compliance
Name
Type number
ROM/FLASH version
LEA-6H
All
LEA-6H-0-002
FW6.02, FW 7.01, FW 7.03
FW1.00
LEA-6N
All
FW1.00
LEA-6S
All
ROM6.02, ROM7.03
LEA-6A
All
ROM6.02, ROM7.03
LEA-6T-0
All
ROM6.02, ROM7.03
LEA-6T-1
All
FW 7.03
LEA-6T-2
All
FW 6.02
LEA-6R
All
FW DR 1.0, FW 7.03 DR2.0, FW 7.03 DR2.02
NEO-6G
All
ROM6.02, ROM7.03
NEO-6Q
All
ROM6.02, ROM7.03
NEO-6M
All
ROM6.02, ROM7.03
NEO-6P
All
ROM6.02
NEO-6T
All
ROM7.03
NEO-6V
All
ROM7.03
MAX-6G
All
ROM7.03
MAX-6Q
All
ROM7.03
LEA-NEO-MAX-6 complies with all relevant requirements for RED 2014/53/EU. The LEA-NEO-MAX-6 Declaration of Conformity (DoC) is
available at www.u-blox.com within Support > Product resources > Conformity Declaration.
This document applies to the following products:
u-blox reserves all rights to this document and the information contained herein. Products, names, logos and designs described herein may in
whole or in part be subject to intellectual property rights. Reproduction, use, modification or disclosure to third parties of this document or
any part thereof without the express permission of u-blox is strictly prohibited.
The information contained herein is provided “as is” and u-blox assumes no liability for the use of the information. No warranty, either
express or implied, is given, including but not limited, with respect to the accuracy, correctness, reliability and fitness for a particular purpose
of the information. This document may be revised by u-blox at any time. For most recent documents, visit www.u-blox.com.
Copyright © 2017, u-blox AG.
u-blox is a registered trademark of u-blox Holding AG in the EU and other countries.
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Preface
u-blox Technical Documentation
As part of our commitment to customer support, u-blox maintains an extensive volume of technical
documentation for our products. In addition to our product-specific technical data sheets, the following manuals
are available to assist u-blox customers in product design and development.
GPS Compendium: This document, also known as the GPS book, provides a wealth of information
regarding generic questions about GPS system functionalities and technology.
Receiver Description and Protocol Specification: Messages, configuration and functionalities of the u-
blox M8 software releases and receivers are explained in this document.
Hardware Integration Manual: This Manual provides hardware design instructions and information on
how to set up production and final product tests.
Application Note: Provides general design instructions and information that applies to all u-blox GNSS
receivers. See section Related documents for a list of Application Notes related to your GNSS receiver.
How to use this manual
This manual has a modular structure. It is not necessary to read it from the beginning to the end.
The following symbols are used to highlight important information within the manual:
An index finger points out key information pertaining to chipset integration and performance.
A warning symbol indicates actions that could negatively impact or damage the receiver.
Questions
If you have any questions about u-blox M8 Hardware Integration:
Read this manual carefully.
Contact our information service on the homepage www.u-blox.com.
Read the questions and answers on our FAQ database on the homepage.
Technical support
Worldwide web
Our website (www.u-blox.com) is a rich pool of information. Product information, technical documents and
helpful FAQ can be accessed 24h a day.
By E-mail
If you have technical problems or cannot find the required information in the provided documents, contact the
nearest Technical Support office. Use the email addresses in the contact details at the end of this document
rather than a personal email address of our staff. This ensures that your request is processed as soon as possible.
Helpful information when contacting technical support
When contacting Technical Support, have the following information ready:
Receiver type (e.g. LEA-6A-0-000), Datacode (e.g. 160200.0300.000) and firmware version (e.g. FW6.02)
Receiver configuration
Clear description of your question or the problem together with a u-center logfile
A short description of the application
Your complete contact details
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Contents
Preface ................................................................................................................................ 3
Contents .............................................................................................................................. 4
1 Hardware description .................................................................................................. 7
1.1 Overview .............................................................................................................................................. 7
1.2 Architecture .......................................................................................................................................... 7
1.3 Power management ............................................................................................................................. 8
1.3.1 Connecting power ........................................................................................................................ 8
1.3.2 Operating modes .......................................................................................................................... 9
1.4 Antenna supply - V_ANT (LEA-6) .......................................................................................................... 9
1.5 System functions ................................................................................................................................ 10
1.5.1 System monitoring ...................................................................................................................... 10
1.6 Interfaces ............................................................................................................................................ 10
1.6.1 UART ........................................................................................................................................... 10
1.6.2 USB (LEA-6/NEO-6) ...................................................................................................................... 10
1.6.3 Display Data Channel (DDC) ........................................................................................................ 11
1.6.4 SPI (NEO-6, LEA-6R) ..................................................................................................................... 13
1.7 I/O pins ............................................................................................................................................... 16
1.7.1 RESET_N ...................................................................................................................................... 16
1.7.2 EXTINT - External interrupt pin ..................................................................................................... 16
1.7.3 AADET_N (LEA-6) ........................................................................................................................ 16
1.7.4 Configuration pins (LEA-6S/6A, NEO-6) ....................................................................................... 16
1.7.5 Second time pulse for LEA-6T-0 and LEA-6T-1 ............................................................................. 16
1.7.6 TX ready signal (FW 7.0x) ............................................................................................................ 17
1.7.7 ANTOFF (NEO-6) .......................................................................................................................... 17
1.7.8 Antenna supervision signals for LEA-6T-0 .................................................................................... 17
1.7.9 LEA-6R considerations ................................................................................................................. 18
2 Design-in ..................................................................................................................... 19
2.1 Checklist ............................................................................................................................................. 19
2.1.1 Design-in checklist ....................................................................................................................... 19
2.1.2 Design considerations .................................................................................................................. 21
2.1.3 Automotive Dead Reckoning (ADR) solutions .............................................................................. 22
2.2 LEA-6 design ...................................................................................................................................... 23
2.2.1 LEA-6 passive antenna design ...................................................................................................... 23
2.2.2 GLONASS HW design recommendations (LEA-6N, LEA-6H-0-002) ............................................... 25
2.2.3 LEA-6R design ............................................................................................................................. 28
2.2.1 Pin description for LEA-6 designs ................................................................................................. 32
2.3 NEO-6 design ..................................................................................................................................... 33
2.3.1 Passive antenna design (NEO-6) ................................................................................................... 33
2.3.2 Pin description for NEO-6 designs ................................................................................................ 35
2.4 MAX-6 design .................................................................................................................................... 36
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2.4.1 MAX-6 passive antenna design.................................................................................................... 36
2.4.2 Pin description for MAX-6 designs ............................................................................................... 37
2.5 Layout ................................................................................................................................................ 37
2.5.1 Footprint and paste mask ............................................................................................................ 37
2.5.2 Placement ................................................................................................................................... 39
2.5.3 Antenna connection and grounding plane design ....................................................................... 40
2.5.4 Antenna micro strip ..................................................................................................................... 41
2.6 Antenna and antenna supervisor ........................................................................................................ 42
2.6.1 Passive antenna ........................................................................................................................... 43
2.6.2 Active antenna (LEA-6) ................................................................................................................ 43
2.6.3 Active antenna bias power (LEA-6) .............................................................................................. 44
2.6.4 Active antenna supervisor (LEA-6)................................................................................................ 45
2.6.5 Active antenna (NEO-6 and MAX-6) ............................................................................................ 48
2.6.6 External active antenna supervisor using ANTOFF (NEO-6) ........................................................... 50
2.6.7 External active antenna supervisor using ANTON (MAX-6) ........................................................... 51
2.6.8 External active antenna control (NEO-6) ...................................................................................... 52
2.6.9 External active antenna control (MAX-6) ..................................................................................... 53
2.6.10 GPS antenna placement for LEA-6R ............................................................................................. 53
3 Product handling ........................................................................................................ 54
3.1 Packaging, shipping, storage and moisture preconditioning ............................................................... 54
3.1.1 Population of Modules ................................................................................................................ 54
3.2 Soldering ............................................................................................................................................ 54
3.2.1 Soldering paste............................................................................................................................ 54
3.2.2 Reflow soldering ......................................................................................................................... 54
3.2.3 Optical inspection ........................................................................................................................ 55
3.2.4 Cleaning ...................................................................................................................................... 56
3.2.5 Repeated reflow soldering ........................................................................................................... 56
3.2.6 Wave soldering............................................................................................................................ 56
3.2.7 Hand soldering ............................................................................................................................ 56
3.2.8 Rework ........................................................................................................................................ 56
3.2.9 Conformal coating ...................................................................................................................... 57
3.2.10 Casting ........................................................................................................................................ 57
3.2.11 Grounding metal covers .............................................................................................................. 57
3.2.12 Use of ultrasonic processes .......................................................................................................... 57
3.3 EOS/ESD/EMI Precautions .................................................................................................................... 57
3.3.1 Abbreviations .............................................................................................................................. 57
3.3.2 Electrostatic discharge (ESD) ........................................................................................................ 57
3.3.3 ESD handling precautions ............................................................................................................ 58
3.3.4 ESD protection measures ............................................................................................................. 59
3.3.5 Electrical Overstress (EOS) ............................................................................................................ 59
3.3.6 EOS protection measures ............................................................................................................. 59
3.3.7 Electromagnetic interference (EMI) .............................................................................................. 60
3.3.8 Applications with wireless modules LEON / LISA .......................................................................... 61
3.3.9 Recommended parts ................................................................................................................... 63
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3.4 Safety precautions .............................................................................................................................. 64
4 Product testing ........................................................................................................... 65
4.1 u-blox in-series production test ........................................................................................................... 65
4.2 Test parameters for OEM manufacturer .............................................................................................. 65
4.3 System sensitivity test ......................................................................................................................... 66
4.3.1 Guidelines for sensitivity tests ...................................................................................................... 66
4.3.2 ‘Go/No go’ tests for integrated devices ........................................................................................ 66
4.3.3 Testing LEA-6R designs ................................................................................................................ 66
4.3.4 Testing NEO-6V designs .............................................................................................................. 67
Appendix .......................................................................................................................... 68
A Abbreviations ............................................................................................................. 68
B Migration to u-blox-6 receivers ................................................................................. 68
B.1 Checklist for migration ....................................................................................................................... 68
B.2 Software migration ............................................................................................................................. 70
B.2.1 Software migration from ANTARIS 4 or u-blox 5 to a u-blox 6 GPS receiver ................................. 70
B.2.2 Software migration from 6.02 to 7.03 ......................................................................................... 71
B.2.3 Software migration from 7.03 to FW1.00 GLONASS, GPS & QZSS ............................................... 71
B.3 Hardware Migration ........................................................................................................................... 71
B.3.1 Hardware Migration: ANTARIS 4 u-blox 6 ............................................................................... 71
B.3.2 Hardware Migration: u-blox 5 u-blox 6 ................................................................................... 71
B.4 Migration of LEA modules .................................................................................................................. 72
B.4.1 Migration from LEA-4 to LEA-6 ................................................................................................... 72
B.4.2 Migration of LEA-4R designs to LEA-6R ....................................................................................... 73
B.4.3 Migration from LEA-5 to LEA-6 ................................................................................................... 74
B.5 Migration of NEO modules ................................................................................................................. 74
B.5.1 Migration from NEO-4S to NEO-6................................................................................................ 74
B.5.2 Migration from NEO-5 to NEO-6 ................................................................................................. 75
C Interface Backgrounder ............................................................................................. 76
C.1 DDC Interface ..................................................................................................................................... 76
C.1.1 Addresses, roles and modes ........................................................................................................ 76
C.1.2 DDC troubleshooting .................................................................................................................. 77
C.2 SPI Interface ........................................................................................................................................ 78
C.2.1 SPI basics ..................................................................................................................................... 78
D DR calibration ............................................................................................................. 81
D.1 Constraints ......................................................................................................................................... 81
D.2 Initial calibration drive ......................................................................................................................... 81
Related documents........................................................................................................... 83
Revision history ................................................................................................................ 84
Contact .............................................................................................................................. 85
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RF Front-End
with
Integrated LNA
Baseband Processor
Power
Management
TCXO or
Crystal
RTC
Cry stal
(opti onal )
FLASH EPROM
(optional)
Antenna
Supervision
& Supply
(optional)
Power Control
RF_IN
V_ANT
AADET_N
VCC_RF
VCC
V_BACKUP
G ND
VCC_OUT
UART
EXTINT
RESET_N
USB V2.0
CFG
Digital
IF Filter
Backup
RAM
ROM Code
GPS/GALILEO
Engine
ARM7TDMI-S
®
SRAM
TIMEPULSE
SAW
Filter
RTC
DDC
SPI (optional)
VCC_IO
ANTON
1
1 Hardware description
1.1 Overview
The u-blox 6 leadless chip carrier (LCC) modules are standalone GPS and GPS/GLONASS/QZSS1 modules featuring
the high performance u-blox-6 positioning engine. These compact, easy to integrate modules combine
exceptional GPS performance with highly flexible power, design, and connectivity options. Their compact form
factors and SMT pads allow fully automated assembly with standard pick & place and reflow-soldering
equipment for cost-efficient, high-volume production enabling short time-to-market.
u-blox positioning modules are not designed for life saving or supporting devices or for aviation and should not
be used in products that could in any way negatively impact the security or health of the user or third parties or
that could cause damage to goods.
1.2 Architecture
u-blox 6 LCC modules consist of two functional parts - the RF and the Baseband sections. See Figure 1 for block
diagrams of the modules.
The RF Front-End includes the input matching elements, the SAW bandpass filter, the u-blox 6 RF-IC (with
integrated LNA) and the frequency source.
The Baseband section contains the u-blox 6 Baseband processor, the RTC crystal and additional elements such as
the optional FLASH Memory for enhanced programmability and flexibility.
Figure 1: u-blox-6 block diagram
GLONASS and QZSS functionality available with LEA-6N, or LEA-6H-0-002 with firmware upgrade.
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VCC
V_BCKP
Voltage
Supervisor
Module Voltage Supply
RTC and Battery Backup RAM (BBR)
J1
1.3 Power management
1.3.1 Connecting power
u-blox 6 receiver modules have three power supply pins: VCC, V_BCKP and VDDUSB.
(No VDDUSB for MAX-6)
1.3.1.1 VCC - main power
The main power supply is fed through the VCC pin. During operation, the current drawn by the u-blox 6 GPS
module can vary by some orders of magnitude, especially, if low-power operation modes are enabled. It is
important that the system power supply circuitry is able to support the peak power (see data sheet for
specification) for a short time. In order to define a battery capacity for specific applications the sustained power
figure shall be used.
When switching from backup mode to normal operation or at start-up u-blox 6 modules must charge the
internal capacitors in the core domain. In certain situations this can result in a significant current draw. For
low power applications using Power Save and backup modes it is important that the power supply or low
ESR capacitors at the module input can deliver this current/charge.
1.3.1.2 V_BCKP - backup battery
In case of a power failure on pin VCC, the real-time clock and backup RAM are supplied through pin V_BCKP.
This enables the u-blox 6 receiver to recover from a power failure with either a Hotstart or a Warmstart
(depending on the duration of VCC outage) and to maintain the configuration settings saved in the backup
RAM. If no backup battery is connected, the receiver performs a Coldstart at power up.
If no backup battery is available connect the V_BCKP pin to GND.
As long as VCC is supplied to the u-blox 6 receiver, the backup battery is disconnected from the RTC and the
backup RAM in order to avoid unnecessary battery drain (see Figure 2). Power to RTC and BBR is supplied from
VCC in this case.
Avoid high resistance on the 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 and possible
malfunctions.
Figure 2: Backup Battery and Voltage
1.3.1.3 VDD_USB - USB interface power supply
On LEA-6 and NEO-6 VDD_USB supplies the USB interface. If the USB interface is not used, the VDD_USB pin
must be connected to GND. For more information regarding the correct handling of VDD_USB, see section
1.6.2.1.
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1.3.2 Operating modes
u-blox 6 modules with FW 7.0x or ROM6.02 have two continuous operating modes (Maximum Performance and
Eco) and one intermittent operating mode (Power Save mode). Maximum Performance mode freely uses the
acquisition engine, resulting in the best possible TTFF, while Eco mode optimizes the use of the acquisition
engine to deliver lower current consumption. At medium to strong signals, there is almost no difference for
acquisition and tracking performance in these modes.
1.3.2.1 Maximum Performance mode
In Maximum Performance mode, u-blox 6 receivers use the acquisition engine at full performance to search for
all possible satellites until the Almanac is completely downloaded.
As a consequence, tracking current consumption level will be achieved when:
A valid GPS position is fixed
Almanac is entirely downloaded
Ephemeris for all satellites in view are valid
1.3.2.2 Eco mode
In Eco mode, u-blox 6 receivers use the acquisition engine to search for new satellites only when needed for
navigation:
In cold starts, u-blox 6 searches for enough satellites to navigate and optimizes use of the acquisition
engine to download their ephemeris.
In non-cold starts, u-blox 6 focuses on searching for visible satellites whose orbits are known from the
Almanac.
In Eco mode, the u-blox 6 acquisition engine limits use of its searching resources to minimize power
consumption. As a consequence the time to find some satellites at weakest signal level might be slightly
increased in comparison to the Maximum Performance mode.
u-blox 6 deactivates the acquisition engine as soon as a position is fixed and a sufficient number (at least 4) of
satellites are being tracked. The tracking engine continues to search and track new satellites without orbit
information.
1.3.2.3 Power Save mode
u-blox 6 receivers include a Power Save Mode. Its operation is called cyclic tracking and allows reducing the
average power consumption significantly. The Power Save Mode can be configured for different update periods.
u-blox recommends an update period of 1s for best GPS performance. For more information, see the u-blox 6
Receiver Description including Protocol Specification [4]
Dead Reckoning, PPP and Precision Timing features should not be used together with Power Save Mode.
Power Save Mode is not supported in GLONASS mode.
1.4 Antenna supply - V_ANT (LEA-6)
LEA-6 modules support active antenna supply and supervision use the pin V_ANT to supply the active antenna.
Use a 10 resistor in front of V_ANT. For more information about antenna and antenna supervisor, see section
2.6.
If not used, connect the V_ANT pin to GND.
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Module
VDD_USB
LDO
VDD_USB
R4
USB_DP
USB_DM
R5
C24 C23
D2
VBUS
DP
DM
GND
USB Device Connector
U1
EN R11
EN
1.5 System functions
1.5.1 System monitoring
The u-blox-6 receiver modules provide system monitoring functions that allow the operation of the embedded
processor and associated peripherals to be supervised. These System Monitoring functions are output as part of
the UBX protocol, class ‘MON’.
Please refer to the u-blox 6 Receiver Description including Protocol Specification [4]. For more information on
UBX messages, serial interfaces for design analysis and individual system monitoring functions.
1.6 Interfaces
1.6.1 UART
u-blox 6 modules include a Universal Asynchronous Receiver Transmitter (UART) serial interface. RxD1/TxD1
supports data rates from 4.8 to 115.2 kBit/s. The signal output and input levels are 0 V to VCC. An interface
based on RS232 standard levels (+/- 12 V) can be realized using level shifters such as Maxim MAX3232.
Hardware handshake signals and synchronous operation are not supported.
For more information, see the LEA-6 Data Sheet [1], NEO-6 Data Sheet [3],or MAX-6 Data Sheet [11].
1.6.2 USB (LEA-6/NEO-6)
The u-blox 6 Universal Serial Bus (USB) interface supports the full-speed data rate of 12 Mbit/s.
1.6.2.1 USB external components
The USB interface requires some external components in order to implement the physical characteristics required
by the USB 2.0 specification. These external components are shown in Figure 3 and listed in Table 1.
In order to comply with USB specifications, VBUS must be connected through a LDO (U1) to pin VDD_USB of
the module.
If the USB device is self-powered it is possible that the power supply (VCC) is shut down and the Baseband-IC
core is not powered. Since VBUS is still available, it still would be signaled to the USB host that the device is
present and ready to communicate. This is not desired and thus the LDO (U1) should be disabled using the
enable signal (EN) of the VCC-LDO or the output of a voltage supervisor. Depending on the characteristics of the
LDO (U1) it is recommended to add a pull-down resistor (R11) at its output to ensure VDD_USB is not floating if
LDO (U1) is disabled or the USB cable is not connected i.e. VBUS is not supplied.
If the device is bus-powered, LDO (U1) does not need an enable control.
Figure 3: USB Interface
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Name
Component
Function
Comments
U1
LDO
Regulates VBUS (4.4 …5.25 V)
down to a voltage of 3.3 V.
Almost no current requirement (~1 mA) if the GPS receiver is operated as a USB
self-powered device, but if bus-powered LDO (U1) must be able to deliver the
maximum current of ~70 mA. A low-cost DC/DC converter such as LTC3410
from Linear Technology may be used as an alternative.
C23,
C24
Capacitors
Required according to the specification of LDO U1
D2
Protection
diodes
Protect circuit from overvoltage
/ ESD when connecting.
Use low capacitance ESD protection such as ST Microelectronics USBLC6-2.
R4, R5
Serial
termination
resistors
Establish a full-speed driver
impedance of 28…44
A value of 22 is recommended.
R11
Resistor
10 k is recommended for USB self-powered setup. For bus-powered setup
R11 can be ignored.
Load Capacitance
Pull-Up Resistor Value R20, R21
50 pF
N/A
100 pF
18 k
250 pF
4.7 k
Table 1: Summary of USB external components
1.6.3 Display Data Channel (DDC)
An I2C compatible Display Data Channel (DDC) interface is available with LEA-6, NEO-6 and MAX-6 modules for
serial communication. For more information about DDC implementation refer to the u-blox 6 Receiver
Description including Protocol Specification [4]. Background information about the DDC interface is available in
Appendix C.1.
u-blox 6 GPS receivers normally run in I2C slave mode. Master Mode is only supported when external
EEPROM is used to store configuration. No other nodes may be connected to the bus. In this case, the
receiver attempts to establish presence of such a non-volatile memory component by writing and reading
from a specific location.
TX ready indicator (data ready) for FW 7.0x. See section 1.7.6.
The u-blox 6 DDC interface supports serial communication with u-blox wireless modules. See the
specification of the applicable wireless module to confirm compatibility.
With u-blox 6, when reading the DDC internal register at address 0xFF (messages transmit buffer), the
master must not set the reading address before every byte accessed as this could cause a faulty behavior.
Since after every byte being read from register 0xFF the internal address counter is incremented by one
saturating at 0xFF, subsequent reads can be performed continuously.
Pins SDA2 and SCL2 have internal 13 k pull-ups. If capacitive bus load is very large, additional external pull-ups
may be needed in order to reduce the pull-up resistance.
Table 2 lists the maximum total pull-up resistor values for the DDC interface. For small loads, e.g. if just
connecting to an external EEPROM, these built-in pull-ups are sufficient.
Table 2: Pull-up resistor values for DDC interface
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1.6.3.1 Communicating to an I
2
C EEPROM with the GPS receiver as I2C master
Serial I2C memory can be connected to the DDC interface. This can be used to save configuration permanently. It
will automatically be recognized by firmware. The memory address must be set to 0b10100000 (0xA0) and the
size fixed to 4 kB.
Figure 4: Connecting external serial I2C memory used by the GPS receiver (see EEPROM data sheet for exact pin orientation)
Figure 5: Connecting external serial I2C memory used by external host (see data sheet for exact pin orientation)
Note that the case shown on Figure 4 is different than the case when EEPROM is present but used by external
host / CPU as indicated on Figure 5. This is allowed but precaution is required to ensure that the GPS receiver
does not detect the EEPROM device, which would effectively configure the GPS receiver to be MASTER on the
bus causing collision with the external host.
To ensure that the EEPROM device (connected to the bus and used by the host) is not detected by the GPS
receiver it is important to set the EEPROM’s address to a value different than 0xA0. This way EEPROM remains
free to be used for other purposes and the GPS receiver will assume the SLAVE mode.
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Manufacturer
Order No.
ST
M24C32-R
Microchip
24AA32A
Catalyst
CAT24C32
Samsung
S524AB0X91
u-blox GPS Receiver SPI Master
SS_N
MISO
SCS_N
MI
VDD
MOMOSI
SCK SCK
VDD
At start up ensure that the host allows enough time (250 ms) for the receiver to interrogate any external
EEPROM over the bus. The receiver always performs this interrogation within 250 ms of start up, and the
external host must provide the GPS receiver sufficient time to complete it. Only after the interrogation can
the host enter MASTER mode and have full control over the bus.
Following I2C serial EEPROM are supported:
Table 3: Recommend parts list for I2C Serial EEPROM memory
1.6.4 SPI (NEO-6, LEA-6R)
A Serial Peripheral Interface (SPI) is available with u-blox 6 NEO modules. The SPI allows for the connection of
external devices with a serial interface, e.g. FLASH memories or A/D converters, or to interface to a host CPU.
LEA-6R includes a Serial Peripheral Interface (SPI) for connecting external sensors. The interface can be operated
in SPI master mode only. Two chip select signals are available to select external slaves. See section 2.2.3.1.
TX ready indicator (data ready) for LEA-6H (FW 7.0x). See section 1.7.6.
Background information about the SPI interface is available in Appendix C.2.
1.6.4.1 Connecting SPI FLASH memory (NEO-6 modules)
SPI FLASH memory can be connected to the SPI interface to save Assist Now Offline data and/or receiver
configuration. It will automatically be recognized by firmware when connected to SS_N.
Figure 6 shows how external memory can be connected. Minimum SPI FLASH memory size is 1 Mbit.
Figure 6: Connecting external SPI Memory to u-blox GPS receivers
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Manufacturer
Order No.
Winbond
W25X10A
Winbond
W25X20A
AMIC
A25L010
AMIC
A25L020
Table 4: Supported SPI FLASH memory devices
u-blox GPS Receiver SPI Master
SS_N
MISO
SCS_N
MI
VDD
MOMOSI
SCK SCK
VDD
Following SPI serial Flash are supported:
Only use serial FLASH types listed in Table 4. For new designs confirm if the listed type is still available. It is
not possible to use other serial FLASH types than those listed in Table 4 with u-blox 6 receivers.
1.6.4.2 SPI communication (connecting to an SPI master) NEO-6
Figure 7 shows how to connect a u-blox GPS receiver to a host/master. The signal on the pins must meet the
conditions specified in the Data Sheet.
Figure 7: Connecting to SPI Master
For those u-blox 6 modules supporting SPI the SPI MOSI, MISO and SCK pins share a configuration
function at start up. To secure correct receiver operation make sure that the SS_N pin is high at start up.
Afterwards the SPI function will not affect the configuration pins.
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Component
Description
Model
Supplier
U1 – U3
Buffer
NC7SZ125
Fairchild
1.6.4.3 Pin configuration with module as one of several slaves
The buffers enabled by the CS_N signal make sure that the GPS receiver starts up with a known defined
configuration, since the SPI pins (MOSI, MISO and SCK) are at start up also configuration pins.
Figure 8: Diagram of SPI Pin Configuration
Table 5: Recommended components for SPI pin configuration
Use same power voltage to supply U1 – U3 and VCC.
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1.7 I/O pins
1.7.1 RESET_N
LEA-6 modules include a RESET_N pin. Driving RESET_N low activates a hardware reset of the system. RESET_N
is only an input and will not reset external circuitry.
Use components with open drain output (i.e. with buffer or voltage supervisor).
There is an internal pull up resistor of 3.3 k to VCC inside the module that requires that the reset circuitry can
deliver enough current (e.g. 1 mA).
Do not drive RESET_N high.
NEO-6 and MAX-6 modules do not include a RESET_N pin. However, this functionality can be implemented for
these modules by connecting the NEO-6 and MAX-6 pin 8 to pin 9 with a 3.3 k resistor, instead of connecting
them directly. Pin 8 (NEO-6) or pin 9 (MAX-6) can then be used as a RESET_N input with the same
characteristics as the reset pin on LEA-6 modules.
Use caution when implementing RESET_N on NEO-6 and MAX-6 modules since forward
compatibility is not guaranteed.
1.7.2 EXTINT - External interrupt pin
EXTINT0 is an external interrupt pin with fixed input voltage thresholds with respect to VCC (see the data sheet
for more information). It can be used for the time mark function on LEA-6T or for wake-up functions in Power
Save Mode on all u-blox 6 LCC modules. Leave open if unused.
1.7.3 AADET_N (LEA-6)
AADET_N is an input pin and is used to report whether an external circuit has detected an external antenna or
not. Low means the antenna has been detected. High means no external antenna has been detected.
See section 2.6.4 for an implementation example.
1.7.4 Configuration pins (LEA-6S/6A, NEO-6)
ROM-based modules provide up to 3 pins (CFG_COM0, CFG_COM1, and CFG_GPS0) for boot-time
configuration. These become effective immediately after start-up. Once the module has started, the
configuration settings can be modified with UBX configuration messages. The modified settings remain effective
until power-down or reset. If these settings have been stored in battery-backup RAM, then the modified
configuration will be retained, as long as the backup battery supply is not interrupted.
The module data sheets indicate the meaning of the configuration pins when they are high (1) or low (0). In fact
no configuration pins need to be pulled high. All have internal pull ups and therefore default to the high (1)
state when left open or connected to a high impedance output. They should be left open unless there is a need
to pull them low to alter the initial configuration.
Some configuration pins are shared with other functions. During start-up, the module reads the state of the
configuration pins. Afterwards the other functions can be used.
The configuration pins of u-blox 6 use an internal pull-up resistor, which determines the default setting.
For more information about settings and messages see the module data sheet.
MAX-6 doesn’t have pins for boot-time configuration.
1.7.5 Second time pulse for LEA-6T-0 and LEA-6T-1
LEA-6T-0 and LEA-6T-1 include a second time pulse pin (TIMEPULSE2). For more information and configuration
see the LEA-6 Data Sheet [1] and also the u-blox 6 Receiver Description including Protocol Specification [4]. (LEA6T-2 provides a single time pulse output only.)
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1.7.6 TX ready signal (FW 7.0x)
The TX ready signal indicates that the receiver has data to transmit. A listener can wait on the TX ready signal
instead of polling the DDC or SPI interfaces. The UBX-CFG-PRT message lets you configure the polarity and the
number of bytes in the buffer before the TX ready signal goes active. The TX ready signal can be mapped to
GPIO 05 (TXD1). The TX ready pin is disabled by default.
The TX-ready functionality can be enabled and configured by proper AT commands sent to the involved
u-blox wireless module supporting the feature. For more information see GPS Implementation Application
Note, Docu No GSM.G1-CS-09007 [14]
1.7.7 ANTOFF (NEO-6)
The ANTOFF signal can be mapped to GPIO22 (Pin 17). The ANTOFF signal is disabled by default.
To configure the ANTOFF function refer to the u-blox 6 Receiver Description including Protocol
Specification [3].
Use caution when implementing ANTOFF configuration since forward compatibility is not
guaranteed
1.7.8 Antenna supervision signals for LEA-6T-0
With LEA-6T-0, the antenna supervisor GPIOs are numbered differently than the other LEA-6 modules and are
wired to specific PIOs:
ANTOFF is internally mapped to GPIO13
ANTSHORT is internally mapped to GPIO17
AADET_N (Active Antenna Detect) is mapped to GPIO8 (Pin 20)
If the unit is reverted to the default configuration, there is no antenna supply.
The CFG-ANT command sets the PIOs and enables Power Control, Short Circuit Detection, Power Down on Short
and Short Circuit Recovery.
To store the settings permanently send the UBX-CFG-CFG command with the option 'save current parameters'
to BBR AND SPI Flash (!)
Also see the schematic of open circuit detection, Figure 46.
To configure this function refer to the u-blox 6 Receiver Description including Protocol Specification [3].
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Pin
Signal name
Direction
Usage
27
SPEED
Input
Odometer Speedpulses
23
SCK
Output
SPI clock
22
SPI_SCS1_N
Output
Chip Select signal for ADC/turn rate sensor
21
FWD
Input
Direction indication (1 = forward)
9
SPI_SCS2_N
Output
Chip Select signal for temperature sensor
2
MISO
Input
Serial data (Master In / Slave Out)
1
MOSI
Output
Serial data (Master Out / Slave In), leave open
1.7.9 LEA-6R considerations
Figure 9: Block schematic of complete LEA-6R design
LEA-6R includes the following special pins: SPI_MOSI, SPI_MISO, SPI_SCS2_N, FWD, SPI_ SCS1_N, SPI_SCK, and SPEED.
Table 6: LEA-6R special pins
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2
2
3
4
5
2 Design-in
For migrating existing ANTARIS®4 product designs to u-blox 6 please refer to Appendix B.
In order to obtain good performance with a GPS receiver module, there are a number of points that require
careful attention during the design-in. These include:
Power Supply: Good performance requires a clean and stable power supply.
Interfaces: Ensure correct wiring, rate and message setup on the module and your host system.
Antenna interface: For optimal performance seek short routing, matched impedance and no stubs.
2.1 Checklist
Good performance requires a clean and stable power supply with minimal ripple. Care needs to be exercised in
selecting a strategy to achieve this. Series resistance in the Vcc supply line can negatively impact performance.
For better performance, use an LDO to provide a clean supply at Vcc and consider the following:
Wide power lines or even power planes are preferred.
Place LDO near the module.
Avoid resistive components in the power line (e.g. narrow power lines, coils, resistors, etc.).
Placing a filter or other source of resistance at Vcc can create significantly longer acquisition times.
2.1.1 Design-in checklist
Designing-in a u-blox 6 module is easy, especially when based on a u-blox reference design. Nonetheless, it pays
to do a quick sanity check of the design. This section lists the most important items for a simple design check.
The Design-In Checklist also helps to avoid an unnecessary respin of the PCB and helps to achieve the best
possible performance.
Follow the design-in checklist when developing any u-blox 6 GPS applications. This can significantly
reduce development time and costs.
Have you chosen the optimal module?
u-blox 6 modules have been intentionally designed to allow GPS receivers to be optimally tailored to specific
applications. Changing between the different variants is easy.
Do you need TCXO performance – Then choose an H
Do you want to be able to upgrade the firmware? Then you will have to use a programmable receiver
module: choose an H2 variant.
Do you need USB? All LEA-6 and NEO-6 modules support USB.
Do you need Dead Reckoning – Then choose a LEA-6R or NEO-6V (see section 2.1.3)
Do you need Precise Point Positioning – Then choose a NEO-6P
Do you need Precision Timing – Then choose a LEA-6T or NEO-6T.
Do you need onboard Antenna Supervisor circuitry - Then choose the LEA form factor.
Do you need onboard Antenna control - Then choose the MAX form factor.
Du you need smallest size and forward compatibility- Then choose the MAX form factor.
Do you need low power - Then choose 1.8V 6G module variant.
Do you need GLONASS - Then choose LEA-6N.
, S3, Q4 or G5 variant.
LEA-6H
LEA-6S
NEO-6Q / MAX-6Q
NEO-6G / MAX-6G
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6
Check Power Supply Requirements and Schematic:
Is the power supply within the specified range? (See data sheet.)
Is the voltage VDDUSB within the specified range?
Compare the peak current consumption of your u-blox 6 module (~70 mA) with the specification of the
power supply.
GPS receivers require a stable power supply, avoid ripple on VCC (<50 mVpp)
For low power applications using Power Save and backup modes, ensure that the power supply or low ESR
capacitors at the module input can deliver the required current/charge for switching from backup mode to
normal operation. In certain situations charging the internal capacitors in the core domain can result in a
significant instantaneous current draw.
Backup Battery
For achieving a minimal Time To First Fix (TTFF) in Hotstart or a Warmstart, connect a backup battery to
V_BCKP.
Time information is a requirement for AssistNow Offline, AssistNow Autonomous and when in Power Save
Mode with update period longer than 10 s.
Antenna
The total noise figure should be well below 3 dB.
If a patch antenna is the preferred antenna, choose a patch of at least 15x15x4 mm. For smaller antennas
an LNA with a noise figure <2 dB is recommended. To optimize TTFF make use of u-blox’ free A-GPS
services AssistNow Online and AssistNow Offline.
Make sure the antenna is not placed close to noisy parts of the circuitry. (e.g. micro-controller, display, etc.)
For active antennas add a 10 resistor in front of V_ANT
input for short circuit protection or use the
antenna supervisor circuitry.
To optimize performance in environments with out-band jamming sources, use an additional SAW filter.
For information on ESD protection for patch antennas and removable antennas, see section 3.3.4 and if
you use GPS for design in combination with GSM or other radio, then check sections 3.3.6 to 3.3.8.
For more information dealing with interference issues see the GPS Antenna Application Note [5].
Schematic
If required, does your schematic allow using different module variants?
Don’t drive RESET_N high!
Don’t drive configuration pins high, they already have internal pull-ups.
Plan the use of 2nd interface (Testpoints on UART, DDC or USB) for firmware updates or as a service
connector.
Layout optimizations (Section 2.5)
Is the GPS module placed according to the recommendation in section 2.5.2?
Has the Grounding concept been followed? (See section 2.5.3.)
Has the micro strip been kept as short as possible?
Add a ground plane underneath the GPS module to reduce interference.
For improved shielding, add as many vias as possible around the micro strip, around the serial
communication lines, underneath the GPS module etc.
Have appropriate EOS/ESD/EMI protection measures been included? (See section 3.3.) This is especially
important for designs including 2G, 3G modules.
Only available with LEA-6 modules
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7
Calculation of the micro strip (Section 2.5.4)
The micro strip must be 50 and be routed in a section of the PCB where minimal interference from noise
sources can be expected.
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 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.
2.1.2 Design considerations
For a minimal design with a u-blox 6 GPS module the following functions and pins need to be considered:
Connect the Power supply to VCC.
VDDUSB: Connect the USB power supply to a LDO before feeding it to VDDUSB and VCC. Or connect to
GND if USB is not used.
Assure a optimal ground connection to all ground pins of the module
Connect the antenna to RF_IN over a matching 50 micro strip and define the antenna supply (V_ANT)
for active antennas (internal or external power supply)
Choose the required serial communication interface (UART, USB, SPI or DDC) and connect the appropriate
pins to your application
If you need Hot- or Warmstart in your application, connect a backup battery to V_BCKP
Decide whether TIMEPULSE or RESET_N7 options are required in your application and connect the
appropriate pins on your module
Only available with LEA-6 modules, but see section 1.7.1 for NEO-6 modules.
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2.1.3 Automotive Dead Reckoning (ADR) solutions
u-blox’ ADR supports different sensor inputs. The classical setup, called “Gyroscope plus Wheel Tick” (GWT),
consists of a gyroscope providing the heading information and wheel tick providing the speed information.
Alternatively, sensor information from left and right wheels (front or rear) or all wheels are used differentially to
deduce heading, called “Differential Wheel Tick” (DWT). This results in slightly lower performance compared to
GWT, but has the big advantage of saving the cost of a gyroscope.
2.1.3.1 Software sensor interface
Figure 10: Software sensor interface
The industry proven u-blox ADR solution is highly flexible. The application processor can support a vast array of
sensors, and must only convert the sensor data into UBX messages and pass them to the GPS receiver via a
standard serial interface (USB, SPI, UART, DDC). This makes the u-blox ADR solution very portable between
various vehicle platforms and reduces development effort and time-to-market. u-blox ADR is completely selfcalibrating, and requires only pre-configuration to the specific vehicle platform.
u-blox’ ADR with software sensor interface is available as NEO-6V module. These components are ideal for
factory installed navigation since they use sensor data (wheel tick and gyroscope data) taken directly from the
CAN bus.
2.1.3.2 Hardware sensor interface
Figure 11: Hardware sensor interface
The standard quality grade LEA-6R module is a dedicated ADR solution (GWT only) for aftermarket installations
with no access to the vehicle bus and no application processor for sensor data processing. Sensors are connected
directly to the module: gyroscopes via SPI and ADC and the speed pulse information from the tachometer.
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USB port
Passive Antenna
Vcc
Micro
Processor
(serial)
(optional)
Backup
Battery
(optional)
+
Micro
Processor
(USB)
1
SDA2 /SPI_MOSI
SCL2 / SPI_MISO
TxD1
RxD1
NC
VCC
GND
VCC_OUT
CFG_COM1/ NC
SPI_SCS2_N /TIMEPULSE2
RESET_N
V_BCKP
Reserved
GND
GND
RF_IN
VCC_RF
V_ANT
Reserved / FWD
Reserved / SPI_SCS1_N
Reserved / SPI_SCK
VDDUSB
USB_DM
USB_DP
EXTINT0 / SPEED
TIMEPULSE
GND
GND
AADET_N
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
LEA-6
Top View
LDO
Passive Antenna
Vcc
Micro
Processor
(serial)
1
SDA2 / SPI_MOSI
SCL2 / SPI_MISO
TxD1
RxD1
NC
VCC
GND
VCC_OUT
CFG_COM1/ NC
SPI_SCS2_N /TIMEPULSE2
RESET_N
V_BCKP
Reserved
GND
GND
RF_IN
VCC_RF
V_ANT
Reserved / FWD
Reserved / SPI_SCS1_N
Reserved / SPI_SCK
VDDUSB
USB_DM
USB_DP
EXTINT0 / SPEED
TIMEPULSE
GND
GND
AADET_N
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
LEA-6
Top View
2.2 LEA-6 design
2.2.1 LEA-6 passive antenna design
This is a minimal setup for a PVT GPS receiver with a LEA-6 module.
Figure 12: LEA-6 passive antenna design with USB port
Figure 13: LEA-6 passive antenna design with no USB port or backup battery
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For best performance with passive antenna designs use an external LNA to increase the sensitivity up to 2
dB. See figure 12 and Figure 15.
LEA-6 / NEO-6 / MAX-6 - Hardware Integration Manual
Passive
Antenna
Vcc
Micro
Processor
(serial)
1
SDA2 / SPI_MOSI
SCL2 / SPI_MISO
TxD1
RxD1
NC
VCC
GND
VCC_OUT
CFG_COM1/ NC
SPI_SCS2_N /TIMEPULSE2
RESET_N
V_BCKP
Reserved
GND
GND
RF_IN
VCC_RF
V_ANT
Reserved / FWD
Reserved / SPI_SCS1_N
NReserved / SPI_SCK
VDDUSB
USB_DM
USB_DP
EXTINT0 / SPEED
TIMEPULSE
GND
GND
AADET_N
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
LEA-6
Top View
LNA
SAW L
Passive
Antenna
Vcc
Micro
Processor
(serial)
1
SDA2 / SPI_MOSI
SCL2 / SPI_MISO
TxD1
RxD1
NC
VCC
GND
VCC_OUT
CFG_COM1/ NC
SPI_SCS2_N /TIMEPULSE2
RESET_N
V_BCKP
Reserved
GND
GND
RF_IN
VCC_RF
V_ANT
Reserved / FWD
Reserved / SPI_SCS1_N
Reserved / SPI_SCK
VDDUSB
USB_DM
USB_DP
EXTINT0 / SPEED
TIMEPULSE
GND
GND
AADET_N
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
LEA-6
Top View
SAW
LNA
SAW
L
Figure 14: LEA-6 passive antenna design for best performance (with external LNA and SAW)
Figure 15: LEA-6 passive antenna design for best performance and increased immunity to jammers such as GSM
For information on increasing immunity to jammers such as GSM see section 3.3.8.
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8
8
2.2.2 GLONASS HW design recommendations (LEA-6N, LEA-6H-0-002
)
The Russian GLONASS satellite system is an alternative system to the US-based Global Positioning System (GPS).
LEA-6N modules can receive and process GLONASS signals. LEA-6H-0-002 modules are GLONASS ready and are
capable of receiving and processing GLONASS signals via a firmware upgrade8.
LEA-6N and LEA-6H-0-002 designs for GLONASS require a wide RF path. Ensure that the antenna and external
SAW filter are sufficient to allow GLONASS & GPS signals to pass (see Figure 16).
Use an active GLONASS antenna. For best performance with passive antenna designs use an external LNA. (See
section 2.2.2.7.)
LEA-6N and LEA-6H-0-002 modules are pin compatible.
2.2.2.1 Wide RF path
As seen in Figure 16, the GLONASS / GPS satellite signals are not at the same frequency. For this reason the RF
path, LNA, filter, and antenna must be modified accordingly to let both signals pass.
2.2.2.2 Filter
Use a GPS & GLONASS SAW filter (see Figure 16) that lets both GPS and GLONASS signals pass. (See the
recommended parts list in section 3.3.9.)
If an active antenna is used, make sure that any filter inside is wide enough.
Figure 16: GPS & GLONASS SAW filter
2.2.2.3 Active antenna
Usually an active GPS antenna includes a GPS band pass filter which might filter out the GLONASS signal (see
Figure 16). For this reason make sure that the filter in the active antenna is wide enough to let the GPS and
GLONASS signals pass.
In combined GPS & GLONASS antennas, the antenna has to be tuned to receive both signals and the filter has a
larger bandwidth to provide optimal GPS & GLONASS signal reception (see Figure 16).
Use a good performance GPS & GLONASS active antenna (for recommended components see section
3.3.9.1).
Figure 17: GPS & GLONASS active antenna
Requires firmware upgrade with FW1.00 GLONASS, GPS & QZSS Flash firmware image, available from u-blox.
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size
Typical bandwidth
36*36*4 mm
40 MHz
25*25*4 mm
20 MHz
18*18*4 mm
10 MHz
15*15*4 mm
8 MHz
12*12*4 mm
7 MHz
10*10*4 mm
5 MHz
2.2.2.4 Passive Antenna
The bandwidth of a ceramic patch antenna narrows with size (see Table 7).
Table 7: Typical bandwidths for GPS patch antennas
Figure 18 shows a 12*12*4 mm patch antenna with 20*20 mm ground plane, tuned to GPS. This patch
bandwidth is so narrow that it cannot be simultaneously matched to GPS and GLONASS.
Figure 18: 12*12*4 patch antenna on 20*20 mm GND plane
Figure 19 shows a 25*25*4 mm patch antenna with 60*60 mm ground plane. Due to the larger bandwidth, it
can be matched to GPS and GLONASS.
Figure 19: 25*25*4 mm patch antenna on 60*60 mm GND plane
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