Telit Wireless Solutions JF2 Hardware User's Manual
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Telit Wireless Solutions JF2 Hardware User's Manual

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JF2
Hardware User Guide
1vv0300985 Rev.5
2018-05-04

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Summary of Contents for Telit Wireless Solutions JF2

  • Page 1 Hardware User Guide 1vv0300985 Rev.5 2018-05-04...

  • Page 2: Notices

    JF2 Hardware User Guide Notices SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE NOTICES While reasonable efforts have been made to ensure the accuracy of this document, Telit assumes no liability resulting from any inaccuracies or omissions in this document, or from use of the information obtained herein.

  • Page 3: Usage And Disclosure Restrictions

    JF2 Hardware User Guide Notices USAGE AND DISCLOSURE RESTRICTIONS License Agreements The software described in this document is the property of Telit and its licensors. It is furnished by express license agreement only and may be used only in accordance with the terms of such an agreement.

  • Page 4: Product Applicability

    JF2 Hardware User Guide Product Applicability PRODUCT APPLICABILITY PRODUCT Table 0-1 Product Applicability Table 1vv0300985 Page 4 of 43 2018-05-04 Rev. 5...

  • Page 5: Table Of Contents

    JF2 Hardware User Guide Contents CONTENTS NOTICES ..........................2 COPYRIGHTS ........................2 COMPUTER SOFTWARE COPYRIGHTS ................2 USAGE AND DISCLOSURE RESTRICTIONS ..............3 PRODUCT APPLICABILITY ....................4 CONTENTS ........................... 5 TABLES ..........................8 FIGURES ..........................8 INTRODUCTION ......................9 Purpose ......................... 9 Audience ........................
  • Page 6 JF2 Hardware User Guide Contents 1.8V Supply Voltage ..................... 15 4.1.1 EEPROM Powerdown ..................16 4.1.2 Capacitance ....................16 Understanding ON-OFF and SYSTEM-ON ............17 4.2.1 Auto-ON Configuration (GPIO8 Control) ............17 4.2.2 Powerup Sequence ..................18 4.2.3 Powerdown Sequence ..................19 Reset Design Details ....................
  • Page 7 JF2 Hardware User Guide Contents Reflow ........................35 Assembly Issues ....................35 PCB LAYOUT DETAILS ..................36 SAFETY RECOMMENDATIONS................37 GLOSSARY AND ACRONYMS ................38 DOCUMENT HISTORY .................... 42 1vv0300985 Page 7 of 43 2018-05-04 Rev. 5...

  • Page 8: Tables

    Table 7-3 – SPI Mode Pin Assignments ..................23 FIGURES Figure 4-1 Initial Application of Power ..................18 Figure 10-1 JF2 Reference Design – Active Antenna ..............32 Figure 11-1 Label for Moisture Sensitive Devices ................34 Figure 12-1 JF2 Pad Design .......................36 1vv0300985...

  • Page 9: Introduction

    JF2 Hardware User Guide Introduction INTRODUCTION Purpose The purpose of this document is to provide information regarding the function, features, and usage of the Telit products listed in Section Product Applicability Please refer to that section for details of the members of the product family.

  • Page 10: Text Conventions

    JF2 Hardware User Guide Introduction Text Conventions All dates are in ISO 8601 format, i.e. YYYY-MM-DD. Danger – This information MUST be followed or catastrophic equipment failure or bodily injury may occur. Caution or Warning – Alerts the user to important points about integrating the module, if these points are not followed, the module and end user Equipment may fail or malfunction.

  • Page 11: Product Variants

    JF2 Hardware User Guide Product Variants PRODUCT VARIANTS The JF2 module has three variants which have different memory architectures: Flash – Memory is implemented using flash and is therefore capable of being reprogrammed to update the firmware image. ROM – Memory is implemented using read-only and cannot be updated.

  • Page 12: Firmware Features And Configuration

    Firmware Features and Configuration FIRMWARE FEATURES AND CONFIGURATION The JF2 can be configured by means of firmware in order to fit better into the overall system. This section describes certain aspects of the receiver that can be configured. Low Power Modes The JF2 module can be operated in one of four power management modes;...

  • Page 13: Internal Lna

    Firmware Features and Configuration Internal LNA The JF2 offers two modes of operation, high gain mode and low gain mode, for the internal LNA. The high gain mode is the default mode and provides 16 to 20dB of gain. The low gain mode provides 6 to 10dB of gain.

  • Page 14: Advanced Features

    L1 frequency for jammers. Any number of jammers that occur outside of a +/-1MHz center band are removed by the JF2 with a 2MHz band pass filter. Up to eight jammers inside this center band are removed using a notch filter.

  • Page 15: Powering The Jf2

    “hibernate”, whereas logic high indicates the module is in “operate” state. If the 1.8 volt DC supply is removed from the JF2 (regardless of power state) it will lose current RTC time and will lose the contents of the internal SRAM. Serial EEPROM corruption is also possible if SYSTEM-ON is high.

  • Page 16: Eeprom Powerdown

    4. Remove power. 4.1.2 Capacitance Aluminum electrolytic capacitors are not recommended at the input to the JF2 due to their high ESR. Tantalum capacitors are recommended with a minimum value of 10uF in parallel with a 0.1uF ceramic capacitor. Ceramic capacitors are also recommended, but make sure the LDO is stable with such capacitors tied to the output.

  • Page 17: Understanding On-Off And System-On

    When power is first applied to the JF2, the internal RTC must start up before the state machine can begin operating. ON-OFF signals applied before the state machine is ready for them may cause unpredictable startup.

  • Page 18: Powerup Sequence

    JF2 Hardware User Guide Powering the JF2 4.2.2 Powerup Sequence Powerup Sequence (with GPIO8 low) – 1. The ON-OFF input must be low. 2. Apply power. 3. Wait for the short pulse from SYSTEM-ON 4. Send a pulse to the ON-OFF pin. Note: see 4.2.1 Auto-ON Configuration (GPIO8 Control)for alternative method.

  • Page 19: Powerdown Sequence

    If an external reset is desired, the signal must be either open collector or open drain without any form of pullup. Do not pull this line high with either a pullup or a driven logic one. When this line is pulled low, the JF2 will immediately drop into hibernate mode with some loss of data.

  • Page 20: Updating The Firmware: Flash Module (Only)

    However, if the internal flash memory needs to be updated, the following steps should be performed to place the JF2 module into a state suitable for programming the internal flash memory. 1. Either remove all power to the module, or force the module into hibernate state by pulsing the ON-OFF signal.

  • Page 21: Updating Patch Code: Eeprom Modules And Rom Modules With Host Memory

    JF2 Hardware User Guide Updating Patch Code: EEPROM modules and ROM modules with Host Memory UPDATING PATCH CODE: EEPROM MODULES AND ROM MODULES WITH HOST MEMORY Both EEPROM modules and ROM modules that use external Host memory support firmware patching. Firmware patches for the EEPROM module are stored inside the I2C serial EEPROM device.

  • Page 22: Main Serial Port

    The GPIO6 pin should be pulled high through a 10K resistor to the 1.8 volt supply. The GPIO7 pin can be left open or pulled high. Upon power up, the JF2 will communicate using a standard asynchronous 8 bit protocol with messages appearing on the TX line, and commands and data being entered on the RX line.

  • Page 23: I2C Mode

    The GPIO7 pin should be pulled low through a 10K resistor to GND. The GPIO6 pin can be left open or pulled low. Upon power up, the JF2 acts as a master transmitter and a slave receiver. Pull- ups to a 1.8V to 3.6V power supply in the range of 1K to 2.2K are required on the RXA and TXA lines when used in I2C mode.

  • Page 24: Host Message Protocols

    If the JF2 is operated in TricklePower mode, a baud rate of at least 38400 is recommended. This reduces the time required for data output and allows the receiver to drop into the lowest power state for a longer average time.

  • Page 25: Mems Sensor/Eeprom Interface

    JF2 Hardware User Guide MEMS Sensor/EEPROM Interface MEMS SENSOR/EEPROM INTERFACE The DR I2C port is used for connecting to MEMS sensors, such as accelerometer or magnetometer. Pullup resistors of approximately 2.2Kohm to 1.8 volts are required on the DR I2C CLK and DR I2C IO lines for proper operation.

  • Page 26: Rf Front End Design

    200E, and the signal level typically goes higher as the satellites have higher elevation angles. The JF2 will display a reported C/No of 40 dB-Hz for a signal level of -130 dBm into the RF input. Each GPS satellite presents its own signal to the JF2, and best performance is obtained when the signal levels are between -125 dBm and -117 dBm.
  • Page 27 JF2 Hardware User Guide RF Front End Design of the remaining satellites will result is a lower accuracy of position. The JF2 reports this geometry in the form of PDOP, HDOP and VDOP. For example, in a vehicular application, the GPS antenna may be placed embedded into the dashboard or rear package tray of an automobile.

  • Page 28: Gps Antenna Polarization

    JF2 Hardware User Guide RF Front End Design GPS Antenna Polarization The GPS signal as broadcast is a right hand circularly polarized signal. The best antenna to receive the GPS signal is a right hand circularly (RHCP) polarized antenna. Remember that IS-GPS-200E specifies the receive power level with a linearly polarized antenna.

  • Page 29: Active Versus Passive Antenna

    LNA is used, either a resistive Pi or T attenuator can be inserted after the LNA to bring the gain down to 14 dB or the JF2 can be switched into a low gain mode by issuing an OSP command to do so.

  • Page 30: Powering An External Lna (Active Antenna)

    The JF2 module contains a SAW filter used in a pre-select configuration with the built in LNA, that is the RF input of the JF2 ties directly into the SAW filter. Any circuit connected to the input of the JF2 would see a complex impedance presented by the SAW filter, particularly out of band, rather than the relatively broad and flat return loss presented by the LNA.

  • Page 31: Rf Trace Losses

    As mentioned earlier, the GPS signals are at - 130 dBm and lower. If signal higher than this are presented to the receiver it can be overwhelmed. The JF2 can reject up to 8 CW in-band jamming signals, but would still be affected by non-CW signals.

  • Page 32: Reference Design

    JF2 Hardware User Guide Reference Design REFERENCE DESIGN Along with power and ground, the minimum signals required to operate the JF2 properly are four digital signals and one RF signal. Figure 10-1 JF2 Reference Design – Active Antenna The RF input can be connected directly to a GPS passive antenna.

  • Page 33: Serial Interface (Uart)

    100 microseconds to change the power state. SYSTEM-ON will then go to a logic one. If the user wishes the JF2 to power up into the ON state and is willing to live with reduced power management options, then ON-OFF can be tied directly to SYSTEM-ON. In this case, GPIO8 should be pulled high with a pullup resistor to VDD_18.

  • Page 34: Handling And Soldering

    This rating is assigned due to some of the components used within the JF2. The JF2 is supplied in trays or tape and reel and is hermetically sealed with desiccant and humidity indicator card. The JF2 parts must be placed and reflowed within 168 hours of first opening the hermetic seal provided the factory conditions are less than 30°C and less than 60% and the...

  • Page 35: Esd

    “Classification Reflow Profiles”. Although IPC/JEDEC J-STD-020 allows for three reflows, the assembly process for the JF2 uses one of those profiles. Therefore, the JF2 is limited to two reflows. Note: JEDEC standards are available for free from the JEDEC website http://www.jedec.org.

  • Page 36: Pcb Layout Details

    PCB Layout Details PCB LAYOUT DETAILS The PCB footprint on the receiving board should match the JF2 pad design shown below. The solder mask opening is generally determined by the component geometry of other parts on the board and can be followed here.

  • Page 37: Safety Recommendations

    JF2 Hardware User Guide Safety Recommendations SAFETY RECOMMENDATIONS PLEASE READ CAREFULLY Be sure that the use of this product is allowed in the country and in the environment required. The use of this product may be dangerous and must be avoided in the following areas: •...

  • Page 38: Glossary And Acronyms

    JF2 Hardware User Guide Glossary and Acronyms GLOSSARY AND ACRONYMS AGPS: Assisted (or Aided) GPS AGPS provides ephemeris data to the receiver to allow faster cold start times than would be possible using only broadcast data. This extended ephemeris data could be either server-generated or locally-generated.
  • Page 39 JF2 Hardware User Guide Glossary and Acronyms GAGAN: The Indian SBAS system. Galileo: The European GNSS currently being built by the European Union (EU) and European Space Agency (ESA). GDOP: Geometric Dilution of Precision A factor used to describe the effect of satellite geometry on the accuracy of the time and position solution of a GNSS receiver.
  • Page 40 JF2 Hardware User Guide Glossary and Acronyms Extended Ephemeris (i.e. predicted) data, calculated by the receiver from broadcast data received from satellites, which is stored in memory. It is usually useful for up to three days. See AGPS. MSAS: MTSAT Satellite Augmentation System The Japanese SBAS system.
  • Page 41 JF2 Hardware User Guide Glossary and Acronyms Electromechanical device used in radio frequency applications. SAW filters are useful at frequencies up to 3 GHz. SBAS: Satellite Based Augmentation System A system that uses a network of ground stations and geostationary satellites to provide differential corrections to GNSS receivers.

  • Page 42: Document History

    JF2 Hardware User Guide Document History DOCUMENT HISTORY Revision Date Changes 2011-01-19 First issue 2012-11-14 Made corrections for Figure 2 2012-11-29 Added ON_OFF notes in section 2.3 and update Figure 4 and 10.1 2013-03-19 Updated ON-OFF section and added ROM2.2 features...
  • Page 43 Mod. 0815...

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