Ublox AMY-6M Hardware Integration Manual
Abstract
This document describes the hardware features and specifications of
the cost effective AMY-6M GPS module featuring the u-blox 6
positioning engine.
The AMY-6M module boasts the industry’s smallest form factor and
is a fully tested standalone solution that requires no host
integration.
This module combines exceptional GPS performance with highly
flexible power, design, and serial communication options.
www.u-blox.com
AMY-6M
u-blox 6 GPS Modules
Hardware Integration Manual
Document Information
Title
AMY-6M
Subtitle
u-blox 6 GPS Modules
Document type
Hardware Integration Manual
Document number
UBX-17021971
Revision and Date
UBX-17021971 – R07
06-Jun-2017
Document status
This document contains data from product verification. Revised and supplementary
data may be published later.
Name
Type number
ROM/FLASH version
PCN reference
AMY-6M
AMY-6M-0-000
ROM6.02
n/a
AMY-6M
AMY-6M-0-001
ROM7.03
n/a
AMY-6M
AMY-6M-0-002
ROM7.03
UBX-TN-12032
This document and the use of any information contained therein, is subject to the acceptance of the u-blox terms and conditions. They
can be downloaded from www.u-blox.com.
u-blox makes no warranties based on the accuracy or completeness of the contents of this document and reserves the right to make
changes to specifications and product descriptions at any time without notice.
u-blox reserves all rights to this document and the information contained herein. Reproduction, use or disclosure to third parties without
express permission is strictly prohibited. Copyright © 2017, u-blox AG.
u-blox® is a registered trademark of u-blox Holding AG in the EU and other countries. ARM® is the registered trademark of ARM Limited in
the EU and other countries.
This document applies to the following products:
AMY-6M - Hardware Integration Manual
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AMY-6M - Hardware Integration Manual
Preface
u-blox Technical Documentation
As part of our commitment to customer support, u-blox maintains an extensive volume of technical
documentation for our products. In addition to our product-specific technical data sheets, the following manuals
are available to assist u-blox customers in product design and development.
GPS Compendium: This document, also known as the GPS book, provides a wealth of information
regarding generic questions about GPS system functionalities and technology.
Receiver Description including Protocol Specification: Messages, configuration and functionalities of
the u-blox 6 software releases and receivers are explained in this document.
Application Note: document provides general design instructions and information that applies to all u-blox
GPS receivers. See Section Related documents for a list of Application Notes related to your GPS receiver.
How to use this Manual
The AMY-6M Hardware Integration Manual provides the necessary information to successfully design in and
configure these u-blox 6-based GPS receiver modules. For navigating this document please note the following:
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 module integration and performance.
A warning symbol indicates actions that could negatively impact or damage the module.
Questions
If you have any questions about u-blox 6 Hardware Integration, please:
Read this manual carefully.
Read the questions and answers on our FAQ database on the homepage http://www.u-blox.com
Contact our information service on the homepage http://www.u-blox.com
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 of the Technical Support offices by email. Use our service pool email addresses rather than any personal
email address of our staff. This makes sure that your request is processed as soon as possible. You will find the
contact details at the end of the document.
Helpful Information when Contacting Technical Support
When contacting Technical Support please have the following information ready:
Receiver type (AMY-6M) and firmware version (e.g. V6.02)
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
2 Design-in ....................................................................................................................... 8
2.1 Power management ............................................................................................................................. 8
2.1.1 Overview ....................................................................................................................................... 8
2.1.2 Power management configuration .............................................................................................. 11
2.1.3 System power consumption ........................................................................................................ 11
2.1.4 How to connect the power supply pins ....................................................................................... 12
2.1.5 Single 2.5…3.6 V supply ............................................................................................................. 13
2.1.6 Single 1.75…2.0 V supply ........................................................................................................... 13
2.1.7 Separate supplies of 1.8 V (1.75…2.0V) and 1.4 V (1.4…3.6V) ................................................... 14
2.1.8 Separate supplies of 3.0 V (2.5…3.6 V) and 1.4 V (1.4…3.6 V) ................................................... 14
2.1.9 External 1.8V DCDC converter ..................................................................................................... 15
2.1.10 Operating modes ........................................................................................................................ 15
2.1.11 Active antenna supply ................................................................................................................. 16
2.2 System functions ................................................................................................................................ 17
2.2.1 EXTINT - external interrupt pin ..................................................................................................... 17
2.2.2 System monitoring ...................................................................................................................... 17
2.2.3 Interference Monitor ................................................................................................................... 17
2.3 Interfaces ............................................................................................................................................ 17
2.3.1 UART ........................................................................................................................................... 17
2.3.2 USB ............................................................................................................................................. 17
2.3.3 Display Data Channel (DDC) ........................................................................................................ 19
2.3.4 SPI ............................................................................................................................................... 20
2.4 I/O Pins ............................................................................................................................................... 23
2.4.1 Peripheral Input Output (PIO) ....................................................................................................... 23
2.4.2 SAFEBOOT_N .............................................................................................................................. 23
2.5 System Configuration ......................................................................................................................... 24
2.5.1 Configuration at start-up ............................................................................................................. 24
2.5.2 Configuration at runtime ............................................................................................................. 26
2.6 RTC .................................................................................................................................................... 26
2.7 RF input .............................................................................................................................................. 27
2.7.1 Active Antenna used ................................................................................................................... 27
2.7.2 Passive Antenna .......................................................................................................................... 27
2.7.3 Increased Jamming Immunity ...................................................................................................... 27
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2.8 Active antenna supervisor ................................................................................................................... 28
2.9 Use RESET input .................................................................................................................................. 29
2.10 Design-in checklist .......................................................................................................................... 30
2.10.1 Schematic design-in checklist for AMY-6M .................................................................................. 30
2.10.2 AMY-6M design .......................................................................................................................... 30
2.10.3 Minimal schematic for AMY-6M .................................................................................................. 31
2.11 Layout design-in checklist ............................................................................................................... 33
2.12 Layout ............................................................................................................................................. 34
2.12.1 Footprint ..................................................................................................................................... 34
2.12.2 Paste mask .................................................................................................................................. 34
2.12.3 Placement ................................................................................................................................... 34
2.13 Migration considerations ................................................................................................................. 35
2.14 EOS/ESD/EMI precautions ................................................................................................................ 36
2.14.1 Abbreviations .............................................................................................................................. 36
2.14.2 Electrostatic Discharge (ESD) ........................................................................................................ 36
2.14.3 ESD protection measures ............................................................................................................. 36
2.14.4 Electrical Overstress (EOS) ............................................................................................................ 37
2.14.5 EOS protection measures ............................................................................................................. 37
2.14.6 Electromagnetic Interference (EMI) .............................................................................................. 37
2.14.7 GSM applications ........................................................................................................................ 38
2.14.8 Recommended parts ................................................................................................................... 40
3 Product handling & soldering .................................................................................... 41
3.1 Packaging, shipping, storage and moisture preconditioning ............................................................... 41
3.2 ESD handling precautions ................................................................................................................... 41
3.3 Soldering ............................................................................................................................................ 41
3.3.1 Soldering paste............................................................................................................................ 41
3.3.2 Reflow soldering ......................................................................................................................... 42
3.3.3 Optical inspection ........................................................................................................................ 42
3.3.4 Repeated reflow soldering ........................................................................................................... 42
3.3.5 Wave soldering............................................................................................................................ 42
3.3.6 Rework ........................................................................................................................................ 42
3.3.7 Conformal coating ...................................................................................................................... 42
3.3.8 Casting ........................................................................................................................................ 42
3.3.9 Use of ultrasonic processes .......................................................................................................... 42
3.4 Safety precautions .............................................................................................................................. 43
4 Product testing ........................................................................................................... 44
4.1 Test parameters for OEM manufacturer .............................................................................................. 44
4.2 System sensitivity test ......................................................................................................................... 44
4.2.1 Guidelines for sensitivity tests ...................................................................................................... 44
4.2.2 ‘Go/No go’ tests for integrated devices ........................................................................................ 44
Appendix .......................................................................................................................... 45
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A Migration to u-blox-6 receivers ................................................................................. 45
A.1 Migration from AMY-5M to AMY-6M ................................................................................................ 45
B Component selection ................................................................................................. 47
B.1 RTC crystal (Y2) .................................................................................................................................. 47
B.2 I2C Serial EEPROM memory ................................................................................................................ 47
B.3 Serial FLASH Memory.......................................................................................................................... 47
B.4 USB line protection (D2) ..................................................................................................................... 47
B.5 USB LDO (U4) ..................................................................................................................................... 47
B.6 Operational amplifier (U31) ................................................................................................................ 48
B.7 Dual open-drain buffer (U32) .............................................................................................................. 48
B.8 Antenna supervisor switch transistor (T31) .......................................................................................... 48
B.9 Ferrite bead filter (FB1) ....................................................................................................................... 48
B.10 Inductor (L) ..................................................................................................................................... 48
B.11 Standard capacitors ........................................................................................................................ 48
B.12 Standard resistors ........................................................................................................................... 49
B.13 LNA (LNA1) ..................................................................................................................................... 49
B.14 SAW Filter (F2) ................................................................................................................................ 49
C Interface Backgrounder ............................................................................................. 50
C.1 DDC Interface ..................................................................................................................................... 50
C.1.1 Addresses, roles and modes ........................................................................................................ 50
C.1.2 DDC troubleshooting .................................................................................................................. 51
C.2 SPI Interface ........................................................................................................................................ 52
C.2.1 SPI basics ..................................................................................................................................... 52
D Glossary ...................................................................................................................... 55
Related documents........................................................................................................... 56
Revision history ................................................................................................................ 56
Contact .............................................................................................................................. 57
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1 Hardware description
1.1 Overview
The AMY-6M is the GPS industry’s smallest standalone receiver. It is a fully tested ROM-based solution that
features the high performance u-blox 6 positioning engine. The AMY-6M has been developed for easy design
and integration and requires no host integration, which enables extremely short times to market.
The AMY-6M offers four different serial interfaces. The receiver provides fast acquisition and excellent tracking
performance at an economical price. Furthermore, 2-layer PCB integration is supported, which brings additional
cost savings.
AMY-6M’s miniature size means that it can be integrated into the smallest portable devices. Advanced
interference suppression mechanisms and innovative RF architecture ensure maximum performance even in
hostile signal environments.
1.2 Architecture
The AMY-6M module consists of two functional parts - the RF and the Baseband sections. See Figure 1 for a
block diagram of the AMY-6M.
The RF section includes the DC-block, the RF input matching, the SAW bandpass filter, the u-blox 6 RF-IC (with
integrated LNA) and the Crystal.
The Baseband section contains the u-blox 6 Baseband processor.
An RTC crystal and additional elements such as an external memory for enhanced programmability and flexibility
are optional.
Figure 1:AMY-6M hardware block schematic
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2 Design-in
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.
With AMY-6M an additional external LNA is mandatory if no active antenna is used.
2.1 Power management
2.1.1 Overview
The power supply circuitry can be adapted to various concepts, depending on the intended application.
Figure 2 gives an overview of the power supply features.
Figure 2: Power supply diagram
2.1.1.1 Main supply voltage
During operation the base-band supply current is supplied through the V_DCDC pin. The built-in LDO generates
the stabilized core voltage VDD_C from V_DCDC. The current at V_DCDC depends heavily on the current system
state and is in general very dynamic.
Use a low-impedance supply (<< 1 Ohm) at the V_DCDC pin.
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u-blox 6 supports use of an external DC/DC converter for improved power efficiency supplying V_DCDC and
eventually the RF section. The DCDC_EN signal allows shutting down this external DC/DC converter when
V_DCDC is not needed. If the DCDC_EN signal shall be used, VDD_IO must be supplied independently of the
DC/DC converter, i.e. these voltages must be supplied even if the DC/DC converter is disabled.
2.1.1.2 Base-band I/O supply voltage
The digital I/Os of the base-band part are supplied with VDD_IO from the host system. The wide range of
VDD_IO allows seamless interfacing to standard logic voltage levels.
VDD_IO must be supplied in order for the system to boot.
2.1.1.3 Base-band core voltages
The core voltages VDD_B and VDD_C core are generated separately to enable main supply VDD_C switch off
while the back-up domain VDD_B remains alive. The core voltages are generated by means of internal LDOs. The
input voltage range of the LDOs is wide and allows the use of several types of batteries.
2.1.1.4 Backup power supply
A backup battery can be connected to V_BCKP to supply the RTC and backup RAM in case of power failure at
the main battery for backup domain (VDD_IO). An internal switch supplies the internal VDD_B power domain in
case VDD_IO drops below the specified minimum value. VDD_IO will supply the VDD_B power domain if a
sufficiently high input voltage is detected. See Figure 3 below and see also section 2.1.1.6.
Figure 3: Supply of Backup Domain (VDD_B)
Limit V_BCKP and VDD_IO to 3.6 V.
2.1.1.5 RF supply voltages
The RF unit is supplied through the VDD_RF pin. This supply voltage can optionally be generated internally with
an LDO from the VDD_3V input. If the supply voltage is 1.8 V, then the VDD_3V must be shorted to the VDD_RF
pin, so that the internal LDO is shorted and there is no voltage drop.
Depending on the application, the RF supply voltage can be supplied from 3 different sources:
1. From the V_DCDC node of the baseband power supply, taking advantage of the optional DC/DC
converter.
2. From the VDD_IO node, in cases where the Main Battery voltage and/or V_DCDC are lower than the
minimum RF supply voltage.
3. From a source independent of the baseband power management pins, e.g. the Main Battery node or a
totally independent voltage source.
In all 3 cases, the connections to VDD_3V and VDD_RF must be made according to the supply voltage range that
is actually supplied.
The RF supply voltage shall be free of noise and low frequency modulations.
There are two other LDOs in the RF unit providing improved supply rejection at very low dropout voltage for the
noise sensitive parts of the RF-circuits.
Insert a ferrite bead (FB1) to isolate the RF supply from digital noise.
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2.1.1.6 Built-in supply voltage monitors
Built-in supply voltage monitors ensure that the system always operates within safe limits. The following
conditions need to be met in order for the system to run properly:
1. The core voltages VDD_C and VDD_B need to be within specification. These voltages are supervised by
internal supply monitors.
2. The I/O voltage VDD_IO needs to be within specification. This voltage is supervised by an internal supply
monitor. This supply monitor has a system configurable threshold done automatically by the Firmware.
3. The RF supply voltage needs to be within specification. This voltage is supervised at pin V_RESET by an
internal supply monitor. The threshold of this supply monitor can be configured using the V_TH pin. If
V_TH is open, the threshold is set for a nominal supply voltage of 1.8 V, if this pin is connected to GND
the threshold is set for a nominal supply voltage of 2.5 V and above.
4. If external memory is used, its supply voltage, i.e. VDD_IO, needs to be within the specification of this
part.
With respect to points 2 and 3 listed above, the voltage that defines the lowest operational boundary condition
of the system shall be supervised at the V_RESET pin. This is usually the RF IC supply voltage (VDD_3V). In
designs using EEPROM memory it may also be VDD_IO. Normally, higher system supply voltages take longer to
rise and fall faster than lower supply voltages, e.g. if in a given application, the RF section requires 1.8 V but
external memory requires 2.7 V, it is advisable to monitor VDD_IO rather than VDD_3V.
With respect to item 4 above the design must ensure that VDD_IO is present and within the operating range of
the external memory at system boot time. Else, the system may fail in detecting the external memory and the
memory will be ignored.
Initially at system start-up, the threshold of the VDD_IO supply monitor is set to its lowest value in order to
ensure the system only starts when I/Os are operational. Once external memory is detected, the threshold will be
adapted according to memory type in order to detect brown-out conditions in case VDD_IO would drop below
the operational range of external memory. The following rules do apply:
1. In case of EEPROM at DDC interface, the VDD_IO threshold is set to 1.8V. All EEPROMs used with u-blox
6 must support operation down to 1.8V. Only EEPROM types listed in Table 14 must be used.
2. In case of Serial FLASH memory at SPI interface, VDD_IO threshold is set according to its type. Only
FLASH memory types listed in Table 15 must be used.
Internally, VDD_B and VDD_C are supervised by power-on reset circuits. Reset signals on backup and core
domains are only released once the respective supply voltages fall within the operational conditions.
After release of the power-on reset on circuit at VDD_C the systems waits for 2048 clock cycles to stabilize
before the clock signal is fed into the core. This ensures system operation only with a clean clock signal.
An additional monitor switches the supply of the back-up region VDD_B (RTC and backup RAM) from VDD_IO to
V_BCKP, once VDD_IO falls below its operational specification. Thus, a separate supply source can be used to
maintain RTC and backup RAM information even if VDD_IO fails. If this feature is not needed, V_BCKP must be
connected to GND.
2.1.1.7 USB interface power supply
VDD_USB supplies the I/Os of the USB interface. If the USB interface is not used, the VDD_USB pin must be
connected to GND.
If the USB interface is being used the system can be either self-powered, i.e. powered independently from the
USB bus, or it can be bus-powered, i.e. powered through the USB connection. In bus-powered mode, the system
supply voltages need to be generated from the USB supply voltage VBUS. See section 2.3.2.
If the application uses USB, the correct USB power mode needs to be configured (bus-powered or self
powered). See the u-blox 6 Receiver Description including Protocol Specification [1].
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BB 1.4 V / RF 1.8 V
BB 1.4 V / RF 2.5 V
Continuous
Acquisition
Continuous
Acquisition
Continuous
Acquisition
mA
mA
mW
mW
mW
mW
RF-IC
20
20
36
36
50
50
BB-IC
17
27
24
38
24
38
Total
37
47
60
74
74
88
Supply Voltage V
LDO [mW]
Single 1.8V DCDC Converter [mW]
1.8
67
83
2.5
93
83 3 111
83
3.3
122
83
4.2
155
83 5 185
83
2.1.2 Power management configuration
Depending on the application, the power supply schematic will differ. Some examples are shown in the
following sections:
Supply voltage nominal 3.3 V (2.5–3.6V) see section 2.1.5
Supply voltage nominal 1.8 V (1.75–2.0V) see section 2.1.6
Direct supply of core voltages (1.75–2.0V for RF part, 1.4–3.6V for digital part) see section 2.1.7
Dual power supply using 3.0V and 1.4V (VDD_3V 3.0 V, V_DCDC 1.4 V) see section 2.1.8
Use of external DCDC converter 1.8V (1.75–2.0V) see section 2.1.9
2.1.3 System power consumption
This chapter is targeted at the design and dimensioning of the system power supply. In order to analyze the
power consumption and supply currents for various scenarios, Table 1 lists the respective supply currents at the
minimum supply voltages which are 1.4V for the baseband part and 1.8V for the RF part. Table 1 further shows
the power consumption if the RF section needs to be supplied with 2.5V
Table 1: Raw Current and Power Consumption (ECO Mode, moderate signal levels)
Table 2 and Table 3 compare the approximate power consumption for the different scenarios and different
system supply voltages. Table 2 shows the continuous power consumption when the system has acquired all
satellites and is running in steady state. Table 3 shows the peak power consumption during signal acquisition.
These two cases allow assessing the dimensioning of peak power and continuous power capabilities of the
power supply circuit. The green and red highlighting illustrates the best and the worst solution in terms of power
consumption.
The following 2 scenarios are being compared:
1. Using linear regulators (LDO) only. For supply voltages up to 3.6 V the built-in LDOs of u-blox 6 can be
used. For higher supply voltages, an additional external LDO is needed. There is no effect on power
consumption or efficiency regardless whether external or built-in LDOs are being used.
2. Using an additional external single output voltage DC/DC converter to generate the intermediate system
supply voltage of 1.8V which then is further regulated by the individual LDOs of base-band and RF-IC.
The maximum system supply voltage is only limited by the external DC/DC converter being used.
For the DC/DC converter, an efficiency of 80% has been assumed in calculating the power values shown in
Table 2 and Table 3. If power-efficiency at high system supply voltages is key for the application, use of an ultrahigh efficiency external DC/DC converter such as Linear Technology’s LTC3410 (2.0 × 2.0 mm2 SC70 package) is
recommended.
Table 2: Continuous Tracking Power Consumption (ECO Mode)
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Supply Voltage [V]
LDO [mW]
Single 1.8V DCDC Converter [mW]
1.8
85
106
2.5
118
106 3 141
106
3.3
155
106
4.2
197
106 5 235
106
Pin
Function
Comments
V_DCDC
Main Core (VDD_C) Supply
Always needs input. The current consumption varies over time (peak currents).
Keep series resistance low to prevent ripple on the power supply.
VDD_3V
Main RF Supply
Supplied by 2.5…3.6V or connected to VDD_RF, depends on supply scheme.
VDD_IO
I/O Supply Voltage
Always needs to be supplied.
V_BCKP
Backup voltage (VDD_B) supply
Connect to GND if not used.
VDD_B
Backup Core Voltage
Leave open.
VDD_C
Main Core Voltage
Leave open.
VDD_RF
RF Core Supply Voltage
Leave open or must be supplied by 1.75…2.0V, depends on supply scheme.
In case of supplied by 1.75…2.0V it also has to be shorted to VDD_3V.
VDD_ANA
Analog Power
Leave open.
VDD_LNA
LNA Power Supply
Leave open.
V_RESET
RESET input
Connect to supervising voltage, mostly to VDD_3V (see 2.1.1.6)
V_TH
Sets Threshold for V_RESET
V_TH = open: V_RESET supervised voltage at nominal 1.8 V.
V_TH= GND: V_RESET supervised voltage at nominal 2.5 V and above.
DCDC_EN
Enable for external DCDC
converter
Leave open if not used. Otherwise connect to enable pin of external DCDC
converter.
VDD_USB
Supply for USB interface
Connect to GND if not used.
Table 3: Acquisition Power Consumption (ECO Mode)
Some conclusions from Table 1 to Table 3:
The most efficient solution is to have a direct 1.4 V / 1.8 V supply available from the system. The respective
application circuit is shown in section 2.1.7
If a 1.8V supply is available the best solution is to supply RF and BB part directly. The respective application
circuit is shown in section 2.1.6.
For supply voltages above 2.5 V, a DC/DC converter having a 1.8 V output voltage should be used for good
efficiency. The respective application circuit is shown in section 2.1.9.
Using only the built-in LDOs of u-blox 6 at supply voltages between 2.5 V and 3.6 V is not efficient but very
cost effective in terms of BoM. The respective application circuit is shown in section 2.1.5
2.1.4 How to connect the power supply pins
Table 4 lists the power supply pins and their connection requirements.
Table 4: Power Supply Pins
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2.1.5 Single 2.5…3.6 V supply
A single 3.0V power supply is very easy to design but is not the most efficient solution to run u-blox 6 receivers
(see section 2.1.3 for details).
Figure 4: Single 2.5…3.6 V supply.
2.1.6 Single 1.75…2.0 V supply
The single 1.8V power supply is a very efficient configuration to run u-blox 6 receivers (see section 2.1.3 for
details).
Figure 5: Single 1.75…2.0 V supply
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2.1.7 Separate supplies of 1.8 V (1.75…2.0V) and 1.4 V (1.4…3.6V)
The dual 1.8V and 1.4V power supply the most efficient configuration to run u-blox 6 receivers (see section
2.1.3 for details). It assures stability since the sensitive RF supply is well separated from the fluctuating base band
power supply.
Figure 6: Separate supplies of 1.8 V and 1.4 V
2.1.8 Separate supplies of 3.0 V (2.5…3.6 V) and 1.4 V (1.4…3.6 V)
It assures a better stability than a single 3.0V power supply as the sensitive RF supply is well separated from the
fluctuating base band power supply.
Figure 7: Dual supplies of 3.0 V and 1.4 V
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2.1.9 External 1.8V DCDC converter
The external DCDC converter providing 1.8V is the most efficient solution for main supply voltages above 2.5V.
Figure 8: External 1.8V DCDC converter
2.1.10 Operating modes
The u-blox AMY-6M features one continuous operating mode (Eco Mode) Eco Mode
In Eco Mode, u-blox AMY-6M uses the acquisition engine to search for new satellites only when needed for
navigation:
In cold starts, u-blox AMY-6M searches for enough satellites to navigate and optimizes use of the acquisition
engine to download their ephemeris.
In non-cold starts, u-blox AMY-6M focuses on searching for visible satellites whose orbits are known from
the Almanac.
In Eco Mode, the u-blox AMY-6M acquisition engine limits use of its searching resources to minimize power
consumption.
u-blox AMY-6M 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.
Power Save Mode and Maximum Performance Mode are not supported by AMY-6M.
Power Save Mode requires an external RTC crystal to schedule system wake-up at pre-defined
intervals.
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2.1.11 Active antenna supply
With AMY-6M active antennas are supplied via an external coil or circuit. AMY-6M does not provide the antenna
bias voltage for active antennas on the RF_IN pin as other u-blox modules do. It is therefore necessary to provide
this voltage outside the module via an inductor as indicated in Figure 9. u-blox recommends using an inductor
from Murata (LQG15HS27NJ02). Alternative parts can be used if the inductor’s resonant frequency matches the
GPS frequency of 1575.42MHz.
Figure 9: Recommended wiring for active antennas
For C and L values see Component Selection Section B.
For optimal performance, it is important to place the inductor as close to the microstrip as possible. Figure
10 illustrates the recommended layout and how it should not be done.
Figure 10: Recommended layout for connecting the antenna bias voltage for AMY-6M
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2.2 System functions
2.2.1 EXTINT - external interrupt pin
EXTINT0 and EXTINT1 are external interrupt pins. It can be used for wake-up functions in low-power modes.
See the u-blox 6 Receiver Description including Protocol Specification [2].
2.2.2 System monitoring
The u-blox-6 GPS Receiver provides System Monitoring functions that allow the operation of the embedded
processor and associated peripherals to be supervised. These System Monitoring functions are being output as
part of the UBX protocol, class ‘MON’.
Please refer to the u-blox 6 Receiver Description including Protocol Specification [2]. For more information on
UBX messages, serial interfaces for design analysis and individual system monitoring functions.
2.2.3 Interference Monitor
New with firmware version 7 and above is the Interference Monitor feature. In contrast to the CW Jamming
Indicator, it is designed to detect both broad band and narrow band jammers. The receiver monitors the
background noise and reports any abnormal behavior.
For more information about the Interference Monitor refer to the u-blox 6 Receiver Description including
Protocol Specification [2].
2.3 Interfaces
u-blox AMY-6 receivers offer a number of different interfaces that can be used to connect to a host CPU: UART,
USB, DDC (I2C compatible), and SPI. Depending on the application any of these interfaces may be selected.
For debugging purposes it is recommended to have a second interface (unused by the actual application)
available on test-points.
New with firmware version 7 and above is the feature that each interface can define a corresponding pin, which
indicates if bytes are ready to be transmitted. The Tx-ready pin can be selected from all PIOs which are not in
use. Each Tx-ready pin is exclusively for one interface and cannot be shared.
See u-blox 6 Receiver Description including Protocol Specification [2] for description of the communication
protocols available at these interfaces and the respective configuration options.
2.3.1 UART
UART 1 (RxD1/TxD1) is the default serial interface. It supports data rates from 4.8 kbit/s to 115.2 kbit/s. An
interface based on RS232 standard levels (+/- 12 V) can be realized using external level shifters such as Maxim
MAX3232.
For the default settings on the messages on UART1 see the AMY-6M Data Sheet [1].
Hardware handshake signals and synchronous operation are not supported.
2.3.2 USB
The u-blox 6 USB interface supports the full-speed data rate of 12 Mbit/s.
2.3.2.1 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 11 and listed in Table 5.
In order to comply with USB specifications, VBUS must be connected through an LDO (U4) to pin VDD_USB of
the module.
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Name
Component
Function
Comments
U4
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 (U4) 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 U4
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 Ohms
A value of 22 Ohms is recommended.
R11
Resistor
Ensures a pull down when LDO
is disabled.
1k Ohms is recommended for USB self-powered setup. For bus-powered setup
R11 is not required.
FB1
Ferrite Bead
Filters Noise at GPS frequency
The AMY-6M can be either bus-powered or self-powered. Bus-powered means the AMY-6M is supplied by the
VBUS voltage from the USB. Self-powered means the AMY-6M is powered by another supply independent from
VBUS supply and just the USB interface VDD_USB is supplied by VBUS (through an LDO (U4)).
Depending on the characteristics of the LDO (U4) it is recommended to add a pull-down resistor (R11) at its
output to ensure VDD_USB is not floating if LDO (U4) is disabled or the USB cable is not connected i.e. VBUS is
not supplied.
All u-blox 6 receivers support both Bus and Self Powered Mode on the USB interface. Please be sure to use the
latest drivers from our website.
Connect VDD_USB to GND if not used.
With config pin CFG_COM0 the AMY-6M can be set to Bus (CFG_COM1=open) or Self Powered
(CFG_COM1=GND)
USB is not compatible with Power Save Mode with FW6.02 and below
Figure 11: USB Interface (bus powered setup)
Table 5: Summary of USB external components
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