LEA M8S / M8T Hardware Integration Manual (UBX 13003140)
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LEA-M8S / LEA-M8T u-blox M8 concurrent GNSS modules Hardware Integration Manual Abstract This document describes the features and specifications of the cost effective and high-performance LEA-M8S and LEA-M8T modules, which feature the u-blox M8 concurrent GNSS engine with reception of GPS, GLONASS, BeiDou and QZSS signals. www.u-blox.com UBX-13003140 - R08 LEA-M8S / LEA-M8T - Hardware Integration Manual Document Information Title LEA-M8S / LEA-M8T Subtitle u-blox M8 concurrent GNSS modules Document type Hardware Integration Manual Document number UBX-13003140 Revision and Date R08 Document status Production Information 21-Oct-2015 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. This document applies to the following products: Product name Type number ROM/FLASH version PCN reference LEA-M8S LEA-M8S-0-01 ROM 2.01 UBX-15015253 LEA-M8T LEA-M8T-0-01 ROM 2.01 / FLASH FW 2.30 TIMRAW 1.02 UBX-15012993 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 © 2015, 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. UBX-13003140 - R08 Production Information Page 2 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Contents Contents.............................................................................................................................. 3 1 Hardware description .................................................................................................. 4 1.1 Overview .................................................................................................................................................................................4 1.2 Configuration ..........................................................................................................................................................................4 1.3 Connecting power ...................................................................................................................................................................4 1.3.1 VCC: Main Supply Voltage ...................................................................................................................................................4 1.3.2 V_BCKP: Backup Supply Voltage ..........................................................................................................................................4 1.3.3 VDD_USB: USB interface power supply .................................................................................................................................5 1.3.4 VCC_RF: Output Voltage RF section......................................................................................................................................5 1.3.5 1.4 V_ANT: Antenna supply .......................................................................................................................................................5 Interfaces .................................................................................................................................................................................5 1.4.1 UART ..................................................................................................................................................................................5 1.4.2 USB.....................................................................................................................................................................................5 1.4.3 Display Data Channel (DDC) .................................................................................................................................................6 1.4.4 SPI (LEA-M8T ONLY) ............................................................................................................................................................6 1.4.5 1.5 TX Ready signal ...................................................................................................................................................................6 I/O pins ....................................................................................................................................................................................7 Electromagnetic interference on I/O lines ...........................................................................................................................................8 2 3 4 Design ........................................................................................................................... 9 2.1 Pin description .........................................................................................................................................................................9 2.2 Minimal design ......................................................................................................................................................................10 2.3 Footprint and paste mask .......................................................................................................................................................10 2.4 Antenna and Antenna supervision ..........................................................................................................................................11 2.4.1 Antenna design with passive antenna .................................................................................................................................11 2.4.2 Active antenna design........................................................................................................................................................12 Migration to u-blox M8 modules .............................................................................. 18 3.1 Migrating u-blox 6 designs to a u-blox M8 module ..................................................................................................................18 3.2 Hardware migration LEA-6N -> LEA-M8S ................................................................................................................................18 3.3 Hardware migration LEA-6T -> LEA-M8T .................................................................................................................................19 3.4 Software migration ................................................................................................................................................................19 Product handling ........................................................................................................ 20 4.1 Packaging, shipping, storage and moisture preconditioning .....................................................................................................20 4.2 Soldering ...............................................................................................................................................................................20 4.3 EOS/ESD/EMI precautions .......................................................................................................................................................23 4.4 Applications with cellular modules ..........................................................................................................................................26 Appendix .......................................................................................................................... 28 Recommended parts............................................................................................................................................................................28 A.1 Design-in recommendations in combination with cellular operation .........................................................................................29 Related documents........................................................................................................... 30 Revision history ................................................................................................................ 30 Contact .............................................................................................................................. 31 UBX-13003140 - R08 Production Information Contents Page 3 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual 1 Hardware description 1.1 Overview LEA-M8S and LEA-M8T are standalone GNSS positioning modules featuring the high performance u-blox M8 positioning engine. They are easy to integrate and combine exceptional positioning performance with highly flexible power, design, and connectivity options. 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. For specific product features, see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2]. To determine which u-blox product best meets your needs, see the product selector tables on the u-blox website. 1.2 Configuration The configuration settings can be modified using UBX protocol configuration messages, more information see the u-blox M8 Receiver Description Including Protocol Specification [3]. The modified settings remain effective until power-down or reset. If these settings have been stored in BBR (Battery Backed RAM), then the modified configuration will be retained, as long as the backup battery supply is not interrupted. The configuration can be saved permanently in flash of the LEA-M8T receiver. 1.3 Connecting power The LEA-M8S and LEA-M8T positioning modules have up to three power supply pins: VCC, V_BCKP and VDD_USB. 1.3.1 VCC: Main Supply Voltage The VCC pin provides the main supply voltage. During operation, the current drawn by the module can vary by some orders of magnitude, especially if enabling low-power operation modes. For this reason, it is important that the supply circuitry is able to support the peak power for a short time (see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2] for detail specification). When switching from backup mode to normal operation or at start-up, the LEA-M8S and LEA-M8T 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. Use a proper GND concept. Do not use any resistors or coils in the power line. 1.3.2 V_BCKP: Backup Supply Voltage If the module supply has a power failure, the V_BCKP pin supplies the real-time clock (RTC) and battery backed RAM (BBR). Use of valid time and the GNSS orbit data at start-up will improve the GNSS performance, i.e. enables hot and warm starts. If no backup battery is connected, the module performs a cold start at power-up. Avoid high resistance on the V_BCKP line: During the switch from main supply to backup supply, a short current adjustment peak can cause high voltage drop on the pin with possible malfunctions. If no backup supply voltage is available, connect the V_BCKP pin to VCC. As long as the LEA-M8S / LEA-M8T module is supplied via the VCC, the backup battery is disconnected from the RTC and the BBR to avoid unnecessary battery drain (see Figure 1). In this case, VCC supplies power to the RTC and BBR. UBX-13003140 - R08 Production Information Hardware description Page 4 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Figure 1: Backup battery and voltage (for exact pin orientation, see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2]) 1.3.3 VDD_USB: USB interface power supply 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 about correctly handling the VDD_USB pin, see section 1.4 1.3.4 VCC_RF: Output Voltage RF section The VCC_RF pin can supply an active antenna or external LNA. For more information, see section 2.4. 1.3.5 V_ANT: Antenna supply The V_ANT pin is available to provide antenna bias voltage to supply an optional external active antenna. For more information, see section 2.4. If not used, connect the V_ANT pin to GND. 1.4 Interfaces 1.4.1 UART The LEA-M8S and LEA-M8T positioning modules include a Universal Asynchronous Receiver Transmitter (UART) serial interface RxD/TxD, which supports configurable baud rates. The baud rates supported are specified in the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2]. The signal output and input levels are 0 V to VCC. An interface based on RS232 standard levels (+/- 12 V) can be implemented using level shifters such as Maxim MAX3232. Hardware handshake signals and synchronous operation are not supported. 1.4.2 USB A USB version 2.0 FS (Full Speed, 12 Mb/s) compatible interface is available for communication as an alternative to the UART. The USB_DP integrates a pull-up resistor to signal a full-speed device to the host. The VDD_USB pin supplies the USB interface. u-blox provides Microsoft® certified USB drivers for Windows Vista, and Windows 7 operating systems (also Windows 8 compatible). These drivers are available at our website at www.u-blox.com USB external components The USB interface requires some external components to implement the physical characteristics required by the USB 2.0 specification. These external components are shown in Figure 2 and listed in Table 1. To comply with USB specifications, VBUS must be connected through an LDO (U1) to pin VDD_USB on the module. The USB device is self-powered, the power supply (VCC) can be turned off and the digital block is not powered. In this case, since VBUS is still available, the USB host would still receive the signal indicating that the device is present and ready to communicate. This should be avoided by disabling the LDO (U1) using the enable signal (EN) of the VCC-LDO or the output of a voltage supervisor. 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 the LDO (U1) is disabled or the USB cable is not connected, i.e. VBUS is not supplied. UBX-13003140 - R08 Production Information Hardware description Page 5 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual USB bus powered is not supported. Figure 2: USB Interface 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) C23, C24 D2 Capacitors R4, R5 R11 Protection diodes Serial termination resistors Resistor Required according to the specification of LDO U1 Protect circuit from overvoltage / ESD when connecting. Establish a full-speed driver impedance of 28…44 Ω Use low capacitance ESD protection such as ST Microelectronics USBLC6-2. A value of 27 Ω is recommended. 100 kΩ is recommended for USB self-powered setup. For bus-powered setup, R11 can be ignored. Table 1: Summary of USB external components 1.4.3 Display Data Channel (DDC) 2 An I C compatible Display Data Channel (DDC) interface is available for serial communication with an external host CPU. The interface only supports operation in slave mode (master mode is not supported). The DDC 2 protocol and electrical interface are fully compatible with the Fast-Mode of the I C industry standard. DDC pins SDA and SCL have internal pull-up resistors. For more information about the DDC implementation, see the u-blox M8 Receiver Description Including Protocol Specification [3]. For bandwidth information, see the LEA-M8S Data Sheet [1]. For timing parameters, consult the I2C-bus specification [8]. The u-blox M8 DDC interface supports serial communication with u-blox cellular modules. See the specification of the applicable cellular module to confirm compatibility. 1.4.4 SPI (LEA-M8T ONLY) An SPI interface is available for communication to a host CPU with LEA-M8T module. SPI is not available in the default configuration, because its pins are shared with the UART and DDC interfaces. The SPI interface can be enabled by connecting D_SEL to ground. For speed and clock frequency, see the NEO/LEA-M8T Data Sheet [2] 1.4.5 TX Ready signal 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 UART TXD (PIO 06). The TX Ready function is disabled by default. The TX-ready functionality can be enabled and configured by AT commands sent to the involved u-blox cellular module supporting the feature. For more information, see the GPS Implementation and Aiding Features in u-blox wireless modules [9]. UBX-13003140 - R08 Production Information Hardware description Page 6 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual 1.5 I/O pins RESET_N: Reset input Driving RESET_N low activates a hardware reset of the system. Use this pin only to reset the module. Do not use RESET_N to turn the module on and off, since the reset state increases power consumption. With LEA-M8S and LEA-M8T modules RESET_N is an input only. RESET_N should be used only in critical situations to recover the system. The Real-Time Clock (RTC) will also be reset and thus immediately afterwards the receiver cannot perform a Hot Start. EXTINT: External interrupt EXTINT is an external interrupt pin with fixed input voltage thresholds with respect to VCC (see the LEA-M8S Data Sheet [1] or the NEO/LEA-M8T Data Sheet [2] for more information). It can be used for wake-up functions in Power Save Mode on all u-blox M8 modules and for aiding. Leave open if unused. SAFEBOOT_N If the SAFEBOOT_N pin is “low” at start up, the u-blox M8 module starts in Safe Boot Mode and doesn’t begin GNSS operation. The Safe Boot Mode can be used to recover from situations where the Flash has become corrupted. D_SEL: Interface select (LEA-M8T ONLY) The D_SEL pin selects the available interfaces. SPI cannot be used simultaneously with UART/DDC. If open, UART and DDC are available. If pulled low, the SPI interface is available. See the NEO/LEA-M8T Data Sheet [2]. Antenna Short circuit detection The LEA-M8S and LEA-M8T modules include internal short circuit antenna detection. For more information, see section 2.4. Antenna open circuit detection The LEA-M8S and LEA-M8T modules provide antenna open circuit detection (OCD) functionality over the AADET_N pin. AADET_N is an input pin used to report whether an external circuit has detected an external antenna or not. Low means an antenna has been detected (antenna consumes current), while high means no external antenna has been detected (no current drawn). This functionality is by default disabled. See section 2.4.2. TIMEPULSE 1 A configurable time pulse signal is available with all u-blox M8 modules. By default, the time pulse signal is configured to 1 pulse per second. For more information, see the u-blox M8 Receiver Description Including Protocol Specification [3]. TIMEPULSE 2 (LEA-M8T only) A configurable time pulse 2 signal is available on LEA-M8T module only. For more information see the u-blox M8 Receiver Description Including Protocol Specification [3]. UBX-13003140 - R08 Production Information Hardware description Page 7 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Electromagnetic interference on I/O lines Any I/O signal line with a length greater than approximately 3 mm can act as an antenna and may pick up arbitrary RF signals transferring them as noise into the GNSS receiver. This specifically applies to unshielded lines, in which the corresponding GND layer is remote or missing entirely, and lines close to the edges of the printed circuit board. If, for example, a cellular signal radiates into an unshielded high-impedance line, it is possible to generate noise in the order of volts and not only distort receiver operation but also damage it permanently. On the other hand, noise generated at the I/O pins will emit from unshielded I/O lines. Receiver performance may be degraded when this noise is coupled into the GNSS antenna (see Figure 19). To avoid interference by improperly shielded lines, it is recommended to use resistors (e.g. R>20 Ω), ferrite beads (e.g. BLM15HD102SN1) or inductors (e.g. LQG15HS47NJ02) on the I/O lines in series. These components should be chosen with care because they will affect also the signal rise times. Figure 3 shows an example of EMI protection measures on the RX/TX line using a ferrite bead. More information can be found in section 4.3. FB RX FB TX GNSS Receiver >10mm BLM15HD102SN1 Figure 3: EMI Precautions UBX-13003140 - R08 Production Information Hardware description Page 8 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual 2 Design 2.1 Pin description Function PIN No I/O Description Remarks Power VCC 6 I Supply Voltage Provide clean and stable supply. GND - Ground VCC_OUT 7, 13, 14, 15, 17 8 O Output Voltage (VCC) Assure a good GND connection to all GND pins of the module Leave open if not used. V_BCKP 11 I Backup Supply Voltage VDD_USB 24 I USB Power Supply RF_IN 16 I GNSS signal input from antenna VCC_RF 18 O Output Voltage RF section V_ANT 19 I Antenna Bias voltage Connect to GND (or leave open) if passive antenna is used. If an active antenna is used, add a 10 Ω resistor in front of V_ANT input to the Antenna Bias Voltage or VCC_RF EXTINT1/ AADET_N TxD (LEA-M8S) 20 I 3 O Ext. Interrupt /Active Antenna Detect Serial Port Ext. Interrupt Pin. Int. pull-up resistor to VCC./ Input pin for optional antenna supervisor circuitry. Leave open if not used. Communication interface can be programmed as TX Ready for DDC interface. Leave open if not used. Serial Port if D_SEL =1(or open) SPI MISO if D_SEL = 0 Serial port input with internal pull-up resistor to VCC. Leave open if not used. Do not use external pull up resistor. Serial Port if D_SEL =1(or open) SPI MOSI if D_SEL = 0 Antenna UART TxD / SPI MISO (LEA-M8T) RxD (LEA-M8S) 4 O TxD SPI MISO I Serial Port I RxD SPI MOSI I/O USB I/O line USB RxD /SPI MOSI (LEA-M8T) USB_DM 25 USB_DP 26 I/O USB I/O line System RESET_N 10 I TIMEPULSE 1 28 O Hardware Reset (Active Low) Timepulse 1 SAFEBOOT_N / 12 TIMEPULSE 2 (LEA-M8T) SAFEBOOT_N (LEA-M8S) EXTINT0 27 I/O Safeboot_N / Timepulse 2 Safeboot_N I Ext. Interrupt SDA (LEA-M8S) SDA /SPI CS_N (LEA-M8T) 1 I/O I/O SCL (LEA-M8S) SCL / SPI CLK (LEA-M8T) 2 I I/O DDC Pins SDA SPI CS_N DDC Pins SCL SPI CLK I/O It is recommended to connect a backup supply voltage to V_BCKP in order to enable Warm and Hot Start features on the positioning modules. Otherwise, connect to VCC. To use the USB interface connect this pin to 3.0 – 3.6V. If no USB serial port used connect to GND. Use a controlled impedance transmission line of 50 Ω to connect to RF_IN. Can be used to power external LNA or an external active antenna (VCC_RF connected to V_ANT with 10 Ω). The max power consumption of the antenna must not exceed the datasheet specification of the module. Leave open if not used. USB2.0 bidirectional communication pin. Leave open if unused. Implementations see section 1.4 Leave open if not used. Do not drive high. Configurable Timepulse signal (one pulse per second by default). Leave open if not used. Configurable Timepulse signal. Must not be held LO during start-up. Must not be held LO during start-up D_SEL (LEA-M8T) 5 Reserved(LEA-M8S) I - Interface Select Reserved Ext. Interrupt Pin. Int. pull-up resistor to VCC. Leave open if unused. DDC Data. Leave open if not used. DDC Data if D_SEL =1 (or open) SPI Chip Select if D_SEL = 0 DDC Clock. Leave open if not used. DDC Clock if D_SEL =1 (or open) SPI Clock if D_SEL = 0 D_SEL = 0 -> SPI, D_SEL =1 (or open) -> DDC Leave open Reserved - Reserved Leave open 9, 21, 22, 23 Table 2: Pinout LEA-M8S / LEA-M8T UBX-13003140 - R08 Production Information Design Page 9 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual 2.2 Minimal design This is a minimal setup for a GNSS receiver with a LEA-M8S / LEA-M8T module: • • • Passive antenna used No backup battery UART for communication Figure 4: LEA-M8S / LEA-M8T passive antenna design For active antenna design, see section 2.4 2.3 Footprint and paste mask Figure 5 describes the footprint and provides recommendations for the paste mask for the LEA-M8S and LEA-M8T modules. These are recommendations only and not specifications. Note that the copper and solder masks have the same size and position. To improve the wetting of the half vias, reduce the amount of solder paste under the module and increase the volume outside of the module by defining the dimensions of the paste mask to form a T-shape (or equivalent) extending beyond the copper mask. For the stencil thickness, see Figure 6. UBX-13003140 - R08 Production Information Design Page 10 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual 0.8 mm [31.5 mil] 2.15 mm [84.5 mil] 3.0 mm [118 mil] 22.4 mm [881.9 mil] 1.1 mm [43 mil] 0.8 mm [31.5 mil] 2.45 mm [96.5 mil] 1.0 mm [39 mil] 17.0 mm [669 mil] Figure 5: LEA-M8S / LEA-M8T footprint Figure 6: LEA-M8S / LEA-M8T paste mask 2.4 Antenna and Antenna supervision 2.4.1 Antenna design with passive antenna A design using a passive antenna requires more attention to the layout of the RF section. Typically, a passive antenna is located near electronic components; therefore, care should be taken to reduce electrical noise that may interfere with the antenna performance. Passive antennas do not require a DC bias voltage and can be directly connected to the RF input pin RF_IN. Sometimes they may also need a passive matching network to match the impedance to 50 Ω. Minimal setup with a good patch antenna Figure 7 shows a minimal setup for a design with a good GNSS patch antenna. Figure 7: Module design with passive antenna (for exact pin orientation see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2]) UBX-13003140 - R08 Production Information Design Page 11 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Setup for best performance with passive antenna Figure 8 shows a design using an external LNA to increase the sensitivity for best performance with passive antenna. Figure 8: Module design with passive antenna and an external LNA (for exact pin orientation see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2].) The VCC_RF output can be used to supply the LNA with a filtered supply voltage. For recommended parts, see Appendix A standard GNSS LNA has enough bandwidth to amplify GPS / GLONASS and BeiDou signals. 2.4.2 Active antenna design Active antennas have an integrated low-noise amplifier. Active antennas require a power supply that will contribute to the total GNSS system power consumption budget with additional 5 to 20 mA typically. If the customers do not want to make use of the internal antenna supervisor and the supply voltage of the LEAM8S / LEA-M8T module matches the supply voltage of the antenna (e.g. 3.0 V), they can use the filtered supply voltage VCC_RF output to supply the antenna (See Figure 9). This design is used for modules in combination with active antenna. In case of different supply voltage, use a filtered external supply, see Figure 10. Active antenna design using VCC_RF pin to supply the active antenna Figure 9: Active antenna design, external supply from VCC_RF (for exact pin orientation see the LEA-M8S Data Sheet [1]) UBX-13003140 - R08 Production Information Design Page 12 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Active antenna design powered from external supply Figure 10 shows a design with direct externally powered active antenna. This circuit has to be used if the active antenna has a different supply voltage than the VCC_RF (for example if a 5 V active antenna is used). Figure 10: Active antenna design, direct external supply (for exact pin orientation see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2]) For recommended parts, see Appendix. In case VCC_RF voltage does not match with the antenna supply voltage, use a filtered external supply as shown in Figure 10. Antenna design with active antenna using antenna supervisor An active antenna supervisor provides the means to check the antenna for open and short circuits and to shut off the antenna supply if a short circuit is detected. The Antenna Supervisor is configured using serial port UBX binary protocol message. Once enabled, the active antenna supervisor produces status messages, reporting in NMEA and/or UBX binary protocol. These indicate the particular state of the antenna supervisor shown in the state diagram (see Figure 11). UBX-13003140 - R08 Production Information Design Page 13 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual The current active antenna status can be determined by polling the UBX-MON-HW monitor command. If an antenna is connected, the initial state after power-up is “Active Antenna OK.” Powerup Disable Supervision No Supervision Disable Supervision Enable Supervision Antenna connected Open Circuit detected Active Antenna OK Periodic reconnection attempts open circuit detected, given OCD enabled Events AADET0_N User controlled events Short Circuit detected Short Circuit detected Short Circuit detected Figure 11: State diagram of active antenna supervisor The module firmware supports an active antenna supervisor circuit, which is connected to the AADET_N pin. For an example of an open circuit detection circuit, see Figure 14. High on AADET_N means that an external antenna is not connected. Status reporting At startup, and on every change of the antenna supervisor configuration, the LEA-M8S and LEA-M8T modules will output an NMEA ($GPTXT) or UBX (INF-NOTICE) message with the internal status of the antenna supervisor (disabled, short detection only, enabled). Abbreviation Description AC Antenna Control (e.g. the antenna will be switched on/ off controlled by the GNSS receiver) SD SR Short Circuit Detection Enabled Short Circuit Recovery Enabled OD PdoS Open Circuit Detection Enabled Power Down on short Table 3: Active Antenna Supervisor Message on startup (UBX binary protocol) To activate the antenna supervisor use the UBX-CFG-ANT message. For further information, refer to the u-blox M8 Receiver Description Including Protocol Specification [3]. Similar to the antenna supervisor configuration, the status of the antenna supervisor will be reported in an NMEA ($GPTXT) or UBX (INF-NOTICE) message at start-up and on every change. UBX-13003140 - R08 Production Information Design Page 14 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Message Description ANTSTATUS=DONTKNOW Active antenna supervisor is not configured and deactivated. ANTSTATUS=OK ANTSTATUS=SHORT Active antenna connected and powered Antenna short ANTSTATUS=OPEN Antenna not connected or antenna defective Table 4: Active antenna supervisor message on startup (NMEA protocol) Module design with active antenna, short circuit protection / detection If a suitably dimensioned R_BIAS series resistor is placed in front of the V_ANT pin, a short circuit can be detected in the antenna supply. The detection happens inside the u-blox M8 module, after which the antenna supply voltage will be immediately shut down. Afterwards, periodic attempts to re-establish antenna power are made by default. An internal switch (under control of the receiver) can turn off the supply to the external antenna whenever it is not needed. This feature helps to reduce power consumption in power save mode. To configure the antenna supervisor use the UBX-CFG-ANT message. For further information, see the u-blox M8 Receiver Description Including Protocol Specification [3]. Short circuits on the antenna input without limitation (R_BIAS) of the current can result in permanent damage to the receiver! Therefore, it is mandatory to implement an R_BIAS in all risk applications, such as situations where the antenna can be disconnected by the end-user or that have long antenna cables. In case VCC_RF voltage does not match with the antenna supply voltage, use a filtered external supply as shown in Figure 13. Supply from VCC_RF Figure 12 shows an active antenna supplied from the LEA-M8S and LEA-M8T modules. LEA-M8S and LEA-M8T modules includes a built in antenna bias supply for nominal 3V antennas enabled by linking the filtered VCC_RF supply output pin to the V_ANT antenna supply input pin with a 10 Ohm resistor in series. The module then controls the power supply to the antenna, applying power whenever the receiver is active and removing power during power-save idle times and if a short-circuit is detected. Short-circuit is detected if the voltage at the antenna supply falls close to zero and is indicated as an alarm in message MONHW Figure 12: Module design with active antenna, internal supply from VCC_RF (for exact pin orientation see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2].) For recommended parts, see Appendix. UBX-13003140 - R08 Production Information Design Page 15 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual External supply Figure 13 shows an externally powered active antenna design. Since the external bias voltage is fed into the most sensitive part of the receiver (i.e. the RF input), this supply should be free of noise. Usually, low frequency analog noise is less critical than digital noise of spurious frequencies with harmonics up to the GPS/QZSS band of 1.575 GHz, GLONASS band of 1.602 GHz and BeiDou band at 1.561 GHz. Therefore, it is not recommended to use digital supply nets to feed the V_ANT pin. Figure 13: Module design with active antenna, external supply (for exact pin orientation see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2]) Antenna supervision with open circuit detection (OCD) Optionally the AADET_N pin may be reassigned to antenna supervision allowing an external circuit to indicate to the module that the antenna is open-circuit. This condition is then reported by the module in message MONHW. Calculate the threshold current using Equation 1. Figure 14: Schematic of open circuit detection (for exact pin orientation see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2].) UBX-13003140 - R08 Production Information Design Page 16 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual R2 R 2 + R3 I= • Vcc _ RF Rbias Equation 1: Calculation of threshold current for open circuit detection If the antenna supply voltage is not derived from VCC_RF, do not exceed the maximum voltage rating of AADET_N. For recommended parts, see Appendix UBX-13003140 - R08 Production Information Design Page 17 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual 3 Migration to u-blox M8 modules 3.1 Migrating u-blox 6 designs to a u-blox M8 module u-blox is committed to ensuring that products in the same form factor are backwards compatible over several technology generations. Utmost care has been taken to ensure there is no negative impact on function or performance and to make u-blox M8 modules as fully compatible as possible with previous generations modules. If using BeiDou, check the bandwidth of the external RF components and the antenna. For information about power consumption, see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2]. It is highly advisable that customers consider a design review with the u-blox support team to ensure the compatibility of key functionalities. 3.2 Hardware migration LEA-6N -> LEA-M8S Pin Pin Name LEA-6N Typical Assignment Pin Name LEA-M8S Typical Assignment 1 SDA DDC Data SDA DDC Data No difference 2 3 SCL TxD DDC Clock Serial Port SCL TxD DDC Clock Serial Port No difference No difference 4 5 RxD NC Serial Port Not Connected RxD Reserved Serial Port Not Connected No difference No difference 6 7 VCC GND Supply voltage Ground (digital) VCC GND Supply voltage Ground (digital) No difference No difference 8 9 VCC_OUT NC Output voltage Not Connected VCC_OUT Reserved Output voltage Not Connected No difference No difference 10 RESET_N External Reset RESET_N External Reset No difference 11 V_BCKP Backup voltage supply V_BCKP Backup voltage supply If this was connected to GND on u-blox 6 module, OK to do the same on u-blox M8. 12 13 Safeboot_N GND Do not drive low Ground Safeboot_N GND Do not drive low Ground No difference No difference 14 15 GND GND Ground Ground GND GND Ground Ground No difference No difference 16 17 RF_IN GND GNSS signal input Ground RF_IN GND GNSS signal input Ground No difference No difference 18 VCC_RF Output Voltage RF section VCC_RF Output Voltage RF section No difference 19 20 V_ANT AADET_N Antenna Bias voltage Active Antenna Detect V_ANT AADET_N Antenna Bias voltage Active Antenna Detect No difference No difference 21 22 Reserved Reserved Not Connected Not Connected Reserved Reserved Not Connected Not Connected No difference No difference 23 24 Reserved VDD_USB Not Connected USB Supply Reserved VDD_USB Not Connected USB Supply No difference No difference 25 USB_DM USB Data USB_DM USB Data No difference 26 27 USB_DP EXTINT0 USB Data External Interrupt Pin USB_DP EXTINT0 USB Data External Interrupt Pin No difference No difference 28 TIMEPULSE Timepulse (1PPS) TIMEPULSE Timepulse (1PPS) No difference Remarks for Migration Table 5: Pin-out comparison LEA-6N vs. LEA-M8S UBX-13003140 - R08 Production Information Migration to u-blox M8 modules Page 18 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual 3.3 Hardware migration LEA-6T -> LEA-M8T LEA-6T Pin LEA-M8T Remarks for Migration 1 Pin Name SDA Typical Assignment DDC Data Pin Name SDA Typical Assignment DDC Data 2 SCL DDC Clock SCL DDC Clock No difference 3 4 TxD RxD Serial Port Serial Port TxD RxD Serial Port Serial Port No difference No difference 5 6 NC VCC Not Connected Supply voltage D_SEL VCC D_SEL =1(or open) Supply voltage Do not drive low No difference 7 8 GND VCC_OUT Ground (digital) Output voltage GND VCC_OUT Ground (digital) Output voltage No difference No difference 9 TIMEPULSE2 2nd Timepulse Not Connected Reserved 10 RESET_N External Reset RESET_N External Reset 11 V_BCKP Backup voltage supply V_BCKP Backup voltage supply If this was connected to GND on u-blox 6 module, OK to do the same on u-blox M8. 12 Safeboot_N Safeboot_N Safeboot_N /Timepulse 2 Must not be held LO during start-up. 13 GND Ground Safeboot_N/ TIMEPULSE2 GND Ground No difference 14 15 GND GND Ground Ground GND GND Ground Ground No difference No difference 16 RF_IN GNSS signal input RF_IN GNSS signal input No difference 17 GND Ground GND No difference 18 VCC_RF Output Voltage RF section VCC_RF 19 V_ANT Antenna Bias voltage V_ANT Ground Output Voltage RF section Antenna Bias voltage No difference No difference No difference Time Pulse 2 is now available on pin 12 (Safeboot_N / Time Pulse 2) No difference No difference 20 AADET_N Active Antenna Detect EXTINT1/AADET_N 21 Reserved Not Connected Reserved External Interrupt Pin/ Active Antenna Detect Not Connected 22 23 Reserved Reserved Not Connected Not Connected Reserved Reserved Not Connected Not Connected No difference No difference 24 VDD_USB USB Supply VDD_USB USB Supply No difference 25 26 USB_DM USB_DP USB Data USB Data USB_DM USB_DP USB Data USB Data No difference No difference 27 28 EXTINT0 TIMEPULSE1 External Interrupt Pin Timepulse (1PPS) EXTINT0 TIMEPULSE1 External Interrupt Pin Timepulse (1PPS) No difference No difference Table 6: Pin-out comparison LEA-6T vs. LEA-M8T 3.4 Software migration For overall description of the module software operation, see the u-blox M8 Receiver Description Including Protocol Specification [3]. All features requiring a flash on LEA-6N are not supported on LEA-M8S. (AssistNow offline / save config) UBX-13003140 - R08 Production Information Migration to u-blox M8 modules Page 19 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual 4 Product handling 4.1 Packaging, shipping, storage and moisture preconditioning For information pertaining to reels and tapes, Moisture Sensitivity levels (MSL), shipment and storage information, as well as drying for preconditioning see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2]. Population of Modules When populating the modules, make sure that the pick and place machine is aligned to the copper pins of the module and not on the module edge. 4.2 Soldering Soldering paste Use of “No Clean” soldering paste is strongly recommended, as it does not require cleaning after the soldering process has taken place. The paste listed in the example below meets these criteria. Soldering Paste: Alloy specification: OM338 SAC405 / Nr.143714 (Cookson Electronics) Sn 95.5/ Ag 4/ Cu 0.5 (95.5% Tin/ 4% Silver/ 0.5% Copper) Melting Temperature: 217 °C Stencil Thickness: See Figure 6. The final choice of the soldering paste depends on the approved manufacturing procedures. The paste-mask geometry for applying soldering paste should meet the recommendations. The quality of the solder joints on the connectors (’half vias’) should meet the appropriate IPC specification. Reflow soldering A convection type-soldering oven is highly recommended over the infrared type radiation oven. Convection heated ovens allow precise control of the temperature, and all parts will heat up evenly, regardless of material properties, thickness of components and surface color. As a reference, see the “IPC-7530 Guidelines for temperature profiling for mass soldering (reflow and wave) processes”, published in 2001. Preheat phase During the initial heating of component leads and balls, residual humidity will be dried out. Note that this preheat phase will not replace prior baking procedures. • Temperature rise rate: max. 3 °C/s. If the temperature rise is too rapid in the preheat phase it may cause excessive slumping. • Time: 60 – 120 s. If the preheat is insufficient, rather large solder balls tend to be generated. Conversely, if performed excessively, fine balls and large balls will be generated in clusters. • End Temperature: 150 – 200 °C. If the temperature is too low, non-melting tends to be caused in areas containing large heat capacity. Heating/ Reflow phase The temperature rises above the liquidus temperature of 217°C. Avoid a sudden rise in temperature as the slump of the paste could become worse. • Limit time above 217 °C liquidus temperature: 40 – 60 s • Peak reflow temperature: 245 °C UBX-13003140 - R08 Production Information Product handling Page 20 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Cooling phase A controlled cooling avoids negative metallurgical effects (solder becomes more brittle) of the solder and possible mechanical tensions in the products. Controlled cooling helps to achieve bright solder fillets with a good shape and low contact angle. • Temperature fall rate: max 4 °C/s To avoid falling off, the u-blox M8 GNSS module should be placed on the topside of the motherboard during soldering. The final soldering temperature chosen at the factory depends on additional external factors like choice of soldering paste, size, thickness and properties of the baseboard, etc. Exceeding the maximum soldering temperature in the recommended soldering profile may permanently damage the module. Figure 15: Recommended soldering profile u-blox M8 modules must not be soldered with a damp heat process. Optical inspection After soldering the u-blox M8 module, consider an optical inspection step to check whether: • The module is properly aligned and centered over the pads • All pads are properly soldered • No excess solder has created contacts to neighboring pads, or possibly to pad stacks and vias nearby Cleaning In general, cleaning the populated modules is strongly discouraged. Residues underneath the modules cannot be easily removed with a washing process. • Cleaning with water will lead to capillary effects where water is absorbed in the gap between the baseboard and the module. The combination of residues of soldering flux and encapsulated water leads to short circuits or resistor-like interconnections between neighboring pads. • Cleaning with alcohol or other organic solvents can result in soldering flux residues flooding into the two housings, areas that are not accessible for post-wash inspections. The solvent will also damage the sticker and the ink-jet printed text. • Ultrasonic cleaning will permanently damage the module, in particular the quartz oscillators. The best approach is to use a “no clean” soldering paste and eliminate the cleaning step after the soldering. UBX-13003140 - R08 Production Information Product handling Page 21 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Repeated reflow soldering Only single reflow soldering processes are recommended for boards populated with u-blox M8 modules. u-blox M8 modules should not be submitted to two reflow cycles on a board populated with components on both sides in order to avoid upside down orientation during the second reflow cycle. In this case, the module should always be placed on that side of the board, which is submitted into the last reflow cycle. The reason for this (besides others) is the risk of the module falling off due to the significantly higher weight in relation to other components. Two reflow cycles can be considered by excluding the above described upside down scenario and taking into account the rework conditions described in section 4. Repeated reflow soldering processes and soldering the module upside down are not recommended. Wave soldering Baseboards with combined through-hole technology (THT) components and surface-mount technology (SMT) devices require wave soldering to solder the THT components. Only a single wave soldering process is encouraged for boards populated with u-blox M8 modules. Hand soldering Hand soldering is allowed. Use a soldering iron temperature-setting equivalent to 350 °C. Place the module precisely on the pads. Start with a cross-diagonal fixture soldering (e.g. pins 1 and 15), and then continue from left to right. Rework The u-blox M8 module can be unsoldered from the baseboard using a hot air gun. When using a hot air gun for unsoldering the module, a maximum of one reflow cycle is allowed. In general, we do not recommend using a hot air gun because this is an uncontrolled process and might damage the module. Attention: use of a hot air gun can lead to overheating and severely damage the module. Always avoid overheating the module. After the module is removed, clean the pads before placing and hand soldering a new module. Never attempt a rework on the module itself, e.g. replacing individual components. Such actions immediately terminate the warranty. In addition to the two reflow cycles, manual rework on particular pins by using a soldering iron is allowed. Manual rework steps on the module can be done several times. Conformal coating ® Certain applications employ a conformal coating of the PCB using HumiSeal or other related coating products. These materials affect the HF properties of the GNSS module and it is important to prevent them from flowing into the module. The RF shields do not provide 100% protection for the module from coating liquids with low viscosity; therefore, care is required in applying the coating. Conformal Coating of the module will void the warranty. Casting If casting is required, use viscose or another type of silicon pottant. The OEM is strongly advised to qualify such processes in combination with the u-blox M8 module before implementing this in the production. Casting will void the warranty. UBX-13003140 - R08 Production Information Product handling Page 22 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Grounding metal covers Attempts to improve grounding by soldering ground cables, wick or other forms of metal strips directly onto the EMI covers is done at the customer’s own risk. The numerous ground pins should be sufficient to provide optimum immunity to interferences and noise. u-blox makes no warranty for damages to the u-blox M8 module caused by soldering metal cables or any other forms of metal strips directly onto the EMI covers. Use of ultrasonic processes Some components on the u-blox M8 module are sensitive to Ultrasonic Waves. Use of any Ultrasonic Processes (cleaning, welding etc.) may cause damage to the GNSS Receiver. u-blox offers no warranty against damages to the u-blox M8 module caused by any Ultrasonic Processes. 4.3 EOS/ESD/EMI precautions When integrating GNSS positioning modules into wireless systems, careful consideration must be given to electromagnetic and voltage susceptibility issues. Wireless systems include components that can produce Electrical Overstress (EOS) and Electro-Magnetic Interference (EMI). CMOS devices are more sensitive to such influences because their failure mechanism is defined by the applied voltage, whereas bipolar semiconductors are more susceptible to thermal overstress. The following design guidelines are provided to help in designing robust yet cost effective solutions. To avoid overstress damage during production or in the field it is essential to observe strict EOS/ESD/EMI handling and protection measures. To prevent overstress damage at the RF_IN of your receiver, never exceed the maximum input power (see the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2]). Electrostatic discharge (ESD) Electrostatic discharge (ESD) is the sudden and momentary electric current that flows between two objects at different electrical potentials caused by direct contact or induced by an electrostatic field. The term is usually used in the electronics and other industries to describe momentary unwanted currents that may cause damage to electronic equipment. ESD handling precautions ESD prevention is based on establishing an Electrostatic Protective Area (EPA). The EPA can be a small working station or a large manufacturing area. The main principle of an EPA is that there are no highly charging materials near ESD sensitive electronics, all conductive materials are grounded, workers are grounded, and charge build-up on ESD sensitive electronics is prevented. International standards are used to define typical EPA and can be obtained for example from International Electrotechnical Commission (IEC) or American National Standards Institute (ANSI). GNSS positioning modules are sensitive to ESD and require special precautions when handling. Particular care must be exercised when handling patch antennas, due to the risk of electrostatic charges. In addition to standard ESD safety practices, the following measures should be taken into account whenever handling the receiver. • Unless there is a galvanic coupling between the local GND (i.e. the work table) and the PCB GND, then the first point of contact when handling the PCB must always be between the local GND and PCB GND. • Before mounting an antenna patch, connect ground of the device UBX-13003140 - R08 Production Information Product handling Page 23 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual • When handling the RF pin, do not come into contact with any charged capacitors and be careful when contacting materials that can develop charges (e.g. patch antenna ~10 pF, coax cable ~50 – 80 pF/m, soldering iron, …) • To prevent electrostatic discharge through the RF input, do not touch any exposed antenna area. If there is any risk that such exposed antenna area is touched in non ESD protected work area, implement proper ESD protection measures in the design. • When soldering RF connectors and patch antennas to the receiver’s RF pin, make sure to use an ESD safe soldering iron (tip). Failure to observe these precautions can result in severe damage to the GNSS module! ESD protection measures GNSS positioning modules are sensitive to Electrostatic Discharge (ESD). Special precautions are required when handling. For more robust designs, employ additional ESD protection measures. Using an LNA with appropriate ESD rating can provide enhanced GNSS performance with passive antennas and increases ESD protection. C LNA L RF_IN B GNSS Receiver A RF_IN Active antennas GNSS Receiver Passive antennas (>2 dBic or performance sufficient) RF_IN Small passive antennas (<2 dBic and performance critical) D GNSS Receiver Most defects caused by ESD can be prevented by following strict ESD protection rules for production and handling. When implementing passive antenna patches or external antenna connection points, then additional ESD measures can also avoid failures in the field as shown in Figure 16. LNA with appropriate ESD rating Figure 16: ESD Precautions Protection measure A is preferred because it offers the best GNSS performance and best level of ESD protection. Electrical Overstress (EOS) Electrical Overstress (EOS) usually describes situations when the maximum input power exceeds the maximum specified ratings. EOS failure can happen if RF emitters are close to a GNSS receiver or its antenna. EOS causes damage to the chip structures. If the RF_IN is damaged by EOS, it is hard to determine whether the chip structures have been damaged by ESD or EOS. UBX-13003140 - R08 Production Information Product handling Page 24 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual EOS protection measures For designs with GNSS positioning modules and wireless (e.g. GSM/GPRS) transceivers in close proximity, ensure sufficient isolation between the wireless and GNSS antennas. If wireless power output causes the specified maximum power input at the GNSS RF_IN to be exceeded, employ EOS protection measures to prevent overstress damage. For robustness, EOS protection measures, as shown in Figure 17, are recommended for designs combining wireless communication transceivers (e.g. GSM, GPRS) and GNSS in the same design or in close proximity. E F GPS Bandpass Filtler LNA LNA with appropriate ESD rating and maximum input power GPS Bandpass Filtler L GNSS Receiver D RF_IN Active antennas (without internal filter which need the module antenna supervisor circuits) GNSS Receiver Passive antennas (>2 dBic or performance sufficient) RF_IN Small passive antennas (<2 dBic and performance critical) GNSS Band pass Filter: SAW or Ceramic with low insertion loss and appropriate ESD rating Figure 17: EOS and ESD Precautions Electromagnetic interference (EMI) Electromagnetic interference (EMI) is the addition or coupling of energy causing a spontaneous reset of the GNSS receiver or resulting in unstable performance. In addition to EMI degradation due to self-jamming (see section 1.5) any electronic device near the GNSS receiver can emit noise that can lead to EMI disturbances or damage. The following elements are critical regarding EMI: • Unshielded connectors (e.g. pin rows etc.) • Weakly shielded lines on PCB (e.g. on top or bottom layer and especially at the border of a PCB) • Weak GND concept (e.g. small and/or long ground line connections) EMI protection measures are recommended when RF emitting devices are near the GNSS receiver. To minimize the effect of EMI a robust grounding concept is essential. To achieve electromagnetic robustness follow the standard EMI suppression techniques. http://www.murata.com/products/emc/knowhow/index.html http://www.murata.com/products/emc/knowhow/pdf/4to5e.pdf Improved EMI protection can be achieved by inserting a resistor or better yet a ferrite bead or an inductor (see Table 7) into any unshielded PCB lines connected to the GNSS receiver. Place the resistor as close as possible to the GNSS receiver pin. Alternatively, feed-thru capacitors with good GND connection can be used to protect e.g. the VCC supply pin against EMI. A selection of feed-thru capacitors are listed in Table 7. UBX-13003140 - R08 Production Information Product handling Page 25 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual 4.4 Applications with cellular modules GSM uses power levels up to 2 W (+33 dBm). Consult the LEA-M8S Data Sheet [1] and the NEO/LEA-M8T Data Sheet [2] for the absolute maximum power input at the GNSS receiver. See the GPS Implementation and Aiding Features in u-blox wireless modules [9]. Isolation between GNSS and GSM antenna In a handheld type design, an isolation of approximately 20 dB can be reached with careful placement of the antennas. If such isolation cannot be achieved, e.g. in the case of an integrated GSM/GNSS antenna, an additional input filter is needed on the GNSS side to block the high energy emitted by the GSM transmitter. Examples of these kinds of filters would be the SAW Filters from Epcos (B9444 or B7839) or Murata. Increasing interference immunity Interference signals come from in-band and out-band frequency sources. In-band interference With in-band interference, the signal frequency is very close to the GNSS constellation frequency used, e.g. GPS frequency of 1575 MHz (see Figure 18). Such interference signals are typically caused by harmonics from displays, micro-controller, bus systems, etc. Power [dBm] Jamming signal 0 GPS Carrier 1575.4 MHz GPS signals Jammin g signal GPS input filter characteristics -110 Frequency [MHz] 1525 1550 1575 1600 1625 Figure 18: In-band interference signals Figure 19: In-band interference sources UBX-13003140 - R08 Production Information Product handling Page 26 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Measures against in-band interference include: • Maintaining a good grounding concept in the design • Shielding • Layout optimization • Filtering • Placement of the GNSS antenna • Adding a CDMA, GSM, WCDMA band pass filter before handset antenna Out-band interference Out-band interference is caused by signal frequencies that are different from the GNSS carrier (see Figure 20). The main sources are wireless communication systems such as GSM, CDMA, WCDMA, Wi-Fi, BT, etc. GSMGSM 900 950 Power [dBm] GPS signals GPS 1575 GSM GSM 1800 1900 0 GPS input filter characteristics -110 Frequency [MHz] 0 500 1000 1500 2000 Figure 20: Out-band interference signals Measures against out-band interference include maintaining a good grounding concept in the design and adding a SAW or band pass ceramic filter (as recommend in section 4) into the antenna input line to the GNSS receiver (see Figure 21). Figure 21: Measures against in-band interference UBX-13003140 - R08 Production Information Product handling Page 27 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Appendix Recommended parts Recommended parts are selected on data sheet basis only. Other components may also be used. Manufacturer Part ID Remarks Parameters to consider Diode ON Semiconductor ESD9R3.3ST5G ESD9L3.3ST5G Standoff Voltage>3.3 V Standoff Voltage>3.3 V Low Capacitance < 0.5 pF Standoff Voltage > Voltage for active antenna SAW TDK/ EPCOS ESD9L5.0ST5G B8401: B39162-B8401-P810 Standoff Voltage>5 V GPS+GLONASS Low Inductance High attenuation TDK/ EPCOS TDK/ EPCOS B3913: B39162B3913U410 B4310: B39162B4310P810 GPS+GLONASS+BeiDou GPS+GLONASS For automotive application Compliant to the AEC-Q200 standard ReyConns muRata NDF9169 SAFFB1G56KB0F0A GPS+ BeiDou GPS+GLONASS+BeiDou Low insertion loss, Only for mobile application Low insertion loss, Only for mobile application muRata SAFEA1G58KB0F00 GPS+GLONASS Low insertion loss, only for mobile application muRata muRata SAFEA1G58KA0F00 SAFFB1G58KA0F0A GPS+GLONASS GPS+GLONASS High attenuation, only for mobile application High attenuation, only for mobile application muRata TAI-SAW SAFFB1G58KB0F0A TA1573A GPS+GLONASS GPS+GLONASS Low insertion loss, Only for mobile application Low insertion loss TAI-SAW TA1343A GPS+GLONASS+BeiDou Low insertion loss TAI-SAW JRC TA0638A NJG1143UA2 GPS+GLONASS+BeiDou LNA Low insertion loss Low noise figure, up to 15 dBm RF input power Avago ALM-GN001 LNA Avago ALM-GN002 LNA Low noise figure, with pre-LNA filter, concurrent GNSS Very low noise figure, with post-LNA filter, concurrent GNSS Inductor Murata LQG15HS27NJ02 L, 27 nH Impedance @ freq GNSS > 500 Ω Capacitor Ferrite Bead Murata Murata GRM1555C1E470JZ01 BLM15HD102SN1 C, 47 pF FB DC-block High IZI @ fGSM Feed thru Capacitor for Signal Feed thru Capacitor Murata NFL18SP157X1A3 NFA18SL307V1A45 Monolithic Type Array Type For data signals, 34 pF load capacitance For data signals, 4 circuits in 1 package Murata NFM18PC …. NFM21P…. 0603 2A 0805 4A Rs < 0.5 Ω LNA Resistor 10 Ω ± 10%, min 0.250 W Rbias 560 Ω ± 5% R2 100 kΩ ± 5% R3, R4 Table 7: Recommended parts Recommended antennas Manufacturer Hirschmann (www.hirschmann-car.com) Taoglas (www.taoglas.com ) Order No. GLONASS 9 M AA.160.301111 Comments GPS+GLONASS active 36*36*4 mm, 3-5V 30mA active Taoglas (www.taoglas.com ) INPAQ (www.inpaq.com.tw) AA.161.301111 B3G02G-S3-01-A 36*36*3 mm, 1.8 to 5.5V / 10mA at 3V active 2.7 to 3.9 V / 10 mA active Amotech (www.amotech.co.kr) B35-3556920-2J2 35x35x3 mm GPS+GLONASS passive Amotech (www.amotech.co.kr) Amotech (www.amotech.co.kr) A25-4102920-2J3 A18-4135920-AMT04 25x25x4 mm GPS+GLONASS passive 18x18x4 mm GPS+GLONASS passive Amotech (www.amotech.co.kr) Amotech AGA363913S0-A1 ACM4-5036-A1-CC-S GPS+GLONASS+ BeiDou active INPAQ (www.inpaq.com.tw) 5.2 x 3.7 x 0.7 mm GPS+GLONASS passive Additional antenna Manufacturer: Allis Communications, Tallysman Wireless Table 8: Recommend antenna UBX-13003140 - R08 Production Information Appendix Page 28 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual A.1 Design-in recommendations in combination with cellular operation Cellular and GNSS Simultaneous operation Receiver Chain MAX-7 NEO-7 EVA-M8 MAX-M8 NEO-M8 LEA-M8 PAM-7 CAM-M8 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Active GNSS Antenna 3G/4G cellular • 2G cellular SAW SAW LNA SAW Any Any Any M C W Q N M P M C W Q N M Q T S T Q C Q On-chip LNA MAX-6 NEO-6 LEA-6 EVA-7 Antenna Family Variant Passive GNSS Antenna 2G/3G/4G cellular Product = optimal performance • = integrated Table 9: Combinations of u-blox GNSS modules with different cellular technologies (2G/3G/4G). See the GPS Implementation and Aiding Features in u-blox wireless modules [9]. UBX-13003140 - R08 Production Information Appendix Page 29 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Related documents [1] LEA-M8S Data Sheet, Docu. No. UBX-14001841 [2] [3] NEO/LEA-M8T Data Sheet Docu. No. UBX-14006196 u-blox M8 Receiver Description Including Protocol Specification (Public version), Docu. No. UBX-13003221 [4] [5] GNSS Firmware 2.01 for u-blox M8 Release Note, Docu. No. UBX-13004697 GPS Antenna Application Note, Docu. No. GPS-X-08014 [6] UBX-M8030 Data Sheet, Docu. No. UBX-13001634 [7] [8] GPS Compendium, Docu. No. GPS-X-02007 I2C-bus specification, Version 2.1, Jan 2000, http://www.nxp.com/acrobat_download/literature/9398/39340011_21.pdf [9] GPS Implementation and Aiding Features in u-blox wireless modules, Docu. No. GSM.G1-CS-09007 For regular updates to u-blox documentation and to receive product change notifications please register on our homepage (http://www.u-blox.com) Revision history Revision Date Name Status / Comments R01 29-Jan-2014 jfur Objective Specification R02 2-Jul-2014 jfur R03 R04 02-Sep-2014 28-Oct-2014 julu jfur R05 R06 07-Jan-2015 20-Apr-2015 julu amil/jfur Advance Information. Updated Table 8 (added Amotech GPS+GLONASS+ BeiDou active antenna); added Table 9: Combinations of u-blox GNSS modules with different cellular technologies (2G/3G/4G). Early Production Information Added LEA-M8T variant, updated EXTINT1/AADET_N (Pin 20) in Table 2, added SAFEBOOT_N pin description in Figure 4, Table 2, Table 5 and Table 6. Production Information Updated Section 1.3 (power), updated Table 7 (Recommended parts) and Table 9, LEA-M8T PCN FW TIMRAW 1.02 R07 R08 02-Jun-2015 21-Oct-2015 julu julu UBX-13003140 - R08 Updated section 1.5 (added Electromagnetic interference on I/O lines). Updated product type number to LEA-M8S-0-01 and added relevant PCN reference Production Information Appendix Page 30 of 31 LEA-M8S / LEA-M8T - Hardware Integration Manual Contact For complete contact information, visit us at www.u-blox.com u-blox Offices North, Central and South America u-blox America, Inc. Phone: E-mail: +1 703 483 3180 info_us@u-blox.com Regional Office West Coast: Phone: +1 408 573 3640 E-mail: info_us@u-blox.com Headquarters Europe, Middle East, Africa Asia, Australia, Pacific u-blox AG Phone: E-mail: Support: Phone: E-mail: Support: +41 44 722 74 44 info@u-blox.com support@u-blox.com Technical Support: Phone: E-mail: +1 703 483 3185 support_us@u-blox.com u-blox Singapore Pte. Ltd. +65 6734 3811 info_ap@u-blox.com support_ap@u-blox.com Regional Office Australia: Phone: +61 2 8448 2016 E-mail: info_anz@u-blox.com Support: support_ap@u-blox.com Regional Office China (Beijing): Phone: +86 10 68 133 545 E-mail: info_cn@u-blox.com Support: support_cn@u-blox.com Regional Office China (Chongqing): Phone: E-mail: Support: +86 23 6815 1588 info_cn@u-blox.com support_cn@u-blox.com Regional Office China (Shanghai): Phone: E-mail: Support: +86 21 6090 4832 info_cn@u-blox.com support_cn@u-blox.com Regional Office China (Shenzhen): Phone: E-mail: Support: +86 755 8627 1083 info_cn@u-blox.com support_cn@u-blox.com Regional Office India: Phone: +91 959 1302 450 E-mail: info_in@u-blox.com Support: support_in@u-blox.com Regional Office Japan (Osaka): Phone: +81 6 6941 3660 E-mail: info_jp@u-blox.com Support: support_jp@u-blox.com Regional Office Japan (Tokyo): Phone: E-mail: Support: +81 3 5775 3850 info_jp@u-blox.com support_jp@u-blox.com Regional Office Korea: Phone: +82 2 542 0861 E-mail: info_kr@u-blox.com Support: support_kr@u-blox.com Regional Office Taiwan: Phone: +886 2 2657 1090 E-mail: info_tw@u-blox.com Support: support_tw@u-blox.com UBX-13003140 - R08 Production Information Contact Page 31 of 31
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