Telit Communications S p A LM940 LM940 User Manual User Guide

Telit Communications S.p.A. LM940 User Guide

User Guide

   [01.2017] Mod.0818 2017-01 Rev.0            LM940  HW Design Guide 1VV0301352 Rev. 2 –2017-07-19
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 2 of 68  2017-07-19  SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE NOTICE   While reasonable efforts have been made to assure 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. The information in this document has been carefully checked  and  is  believed  to  be  reliable.  However,  no  responsibility  is  assumed  for inaccuracies  or  omissions.  Telit  reserves  the  right  to  make  changes  to  any  products described herein and reserves the right to revise this document and to make changes from time to time in content hereof with no obligation to notify any person of revisions or changes. Telit  does  not  assume  any  liability  arising  out  of  the  application  or  use  of  any  product, software, or circuit described herein; neither does it convey license under its patent rights or the rights of others. It  is  possible  that  this  publication  may  contain  references  to,  or  information  about  Telit products (machines and programs), programming, or services that are not announced in your  country.  Such  references  or  information  must  not  be  construed  to  mean  that  Telit intends to announce such Telit products, programming, or services in your country. COPYRIGHTS This instruction manual and the Telit products described in this instruction manual may be, include  or  describe  copyrighted  Telit  material,  such  as  computer  programs  stored  in semiconductor memories or other media. Laws in the Italy and other countries preserve for Telit  and  its  licensors  certain  exclusive  rights  for  copyrighted  material,  including  the exclusive right to copy, reproduce in any form, distribute and make derivative works of the copyrighted  material.  Accordingly,  any  copyrighted  material  of  Telit  and  its  licensors contained herein or in the Telit products described in this instruction manual may not be copied,  reproduced,  distributed,  merged  or  modified  in  any  manner  without  the  express written permission of Telit. Furthermore, the purchase of Telit products shall not be deemed to  grant  either  directly  or  by  implication,  estoppel,  or  otherwise,  any  license  under  the copyrights, patents or patent applications of Telit, as arises by operation of law in the sale of a product. COMPUTER SOFTWARE COPYRIGHTS The  Telit  and  3rd  Party  supplied  Software  (SW)  products  described  in  this  instruction manual  may  include  copyrighted  Telit  and  other  3rd  Party  supplied  computer  programs stored in semiconductor memories or other media. Laws  in  the  Italy  and  other countries preserve for Telit and other 3rd Party supplied SW certain exclusive rights for copyrighted computer  programs,  including  the  exclusive  right  to  copy  or  reproduce  in  any  form  the copyrighted  computer  program.  Accordingly,  any  copyrighted  Telit or other 3rd Party supplied SW computer programs contained in the Telit products described in this instruction manual may not be copied (reverse engineered) or reproduced in any manner without the express written permission of Telit or the 3rd Party SW supplier. Furthermore, the purchase of Telit products shall not be deemed to grant either directly or by implication, estoppel, or otherwise, any license under the copyrights, patents or patent applications of Telit or other 3rd Party supplied SW, except for the normal non-exclusive, royalty free license to use that arises by operation of law in the sale of a product.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 3 of 68  2017-07-19  USAGE AND DISCLOSURE RESTRICTIONS I.  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. II.  Copyrighted Materials Software  and  documentation  are  copyrighted  materials.  Making  unauthorized  copies  is prohibited  by  law.  No  part  of  the  software  or  documentation  may  be  reproduced, transmitted,  transcribed,  stored  in  a  retrieval  system,  or  translated into  any  language  or computer language, in any form or by any means, without prior written permission of Telit III.  High Risk Materials Components, units, or third-party products used in the product described herein are NOT fault-tolerant and are NOT designed, manufactured, or intended for use as on-line control equipment  in  the  following  hazardous  environments  requiring  fail-safe  controls:  the operation of Nuclear Facilities, Aircraft Navigation or Aircraft Communication Systems, Air Traffic  Control,  Life  Support,  or  Weapons  Systems  (High  Risk  Activities").  Telit  and  its supplier(s) specifically disclaim any expressed or implied warranty of fitness for such High Risk Activities. IV.  Trademarks TELIT  and  the  Stylized  T  Logo  are  registered  in  Trademark  Office.  All  other  product  or service names are the property of their respective owners.  V.  Third Party Rights The software may include Third Party Right software. In this case you agree to comply with all terms and conditions imposed on you in respect of such separate software. In addition to Third Party Terms, the disclaimer of warranty and limitation of liability provisions in this License shall apply to the Third Party Right software. TELIT  HEREBY  DISCLAIMS  ANY  AND  ALL  WARRANTIES  EXPRESS  OR  IMPLIED FROM ANY THIRD PARTIES REGARDING ANY SEPARATE FILES, ANY THIRD PARTY MATERIALS INCLUDED IN THE SOFTWARE, ANY THIRD PARTY MATERIALS FROM WHICH  THE  SOFTWARE  IS  DERIVED  (COLLECTIVELY  “OTHER  CODE”),  AND  THE USE OF ANY OR ALL THE OTHER CODE IN CONNECTION  WITH  THE  SOFTWARE, INCLUDING  (WITHOUT  LIMITATION)  ANY  WARRANTIES  OF  SATISFACTORY QUALITY OR FITNESS FOR A PARTICULAR PURPOSE. NO THIRD PARTY LICENSORS OF OTHER CODE SHALL HAVE ANY LIABILITY FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS), HOWEVER CAUSED AND  WHETHER  MADE  UNDER  CONTRACT,  TORT  OR  OTHER  LEGAL  THEORY, ARISING IN ANY WAY OUT OF THE USE OR DISTRIBUTION OF THE OTHER CODE OR  THE  EXERCISE  OF  ANY  RIGHTS  GRANTED  UNDER  EITHER  OR  BOTH  THIS LICENSE AND THE LEGAL TERMS APPLICABLE TO ANY SEPARATE FILES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 4 of 68  2017-07-19  Applicability Table PRODUCTS  LM940
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 5 of 68  2017-07-19  Contents NOTICE  2 COPYRIGHTS .................................................................................................. 2 COMPUTER SOFTWARE COPYRIGHTS ....................................................... 2 USAGE AND DISCLOSURE RESTRICTIONS ................................................ 3 APPLICABILITY TABLE .................................................................................. 4 CONTENTS ...................................................................................................... 5 1. INTRODUCTION ............................................................................ 9  Scope ............................................................................................. 9  Audience ........................................................................................ 9  Contact Information, Support ......................................................... 9  Text Conventions ......................................................................... 11  Related Documents ...................................................................... 12 2. GENERAL PRODUCT DESCRIPTION ........................................ 13  Overview ...................................................................................... 13  Product Variants and Frequency Bands ....................................... 13 2.2.1. RF Bands per Regional Variant .................................................... 13  Target market ............................................................................... 14  Main features ................................................................................ 14  Block Diagram .............................................................................. 16  TX Output Power .......................................................................... 17  RX Sensitivity ............................................................................... 17  Mechanical specifications ............................................................. 18 2.8.1. Dimensions ................................................................................... 18 2.8.2. Weight .......................................................................................... 18  Environmental Requirements ....................................................... 18 2.9.1. Temperature Range ..................................................................... 18 2.9.2. RoHS Compliance ........................................................................ 19 3. PINS ALLOCATION .................................................................... 20  Pin-out .......................................................................................... 20  LM940 Signals That Must Be Connected ..................................... 24  Pin Layout .................................................................................... 25
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 6 of 68  2017-07-19  4. POWER SUPPLY ........................................................................ 26  Power Supply Requirements ........................................................ 26  Power Consumption ..................................................................... 26  General Design Rules .................................................................. 27 4.3.1. Electrical Design Guidelines ......................................................... 27 4.3.1.1. + 5V Input Source Power Supply – Design Guidelines ................ 27 4.3.2. Thermal Design Guidelines .......................................................... 27 4.3.3. Power Supply PCB layout Guidelines .......................................... 28  RTC .............................................................................................. 29  Reference Voltage ........................................................................ 29  Internal LDO for GNSS bias ......................................................... 30 5. ELECTRICAL SPECIFICATIONS ................................................ 31  Absolute Maximum Ratings – Not Operational ............................. 31  Recommended Operating Conditions .......................................... 31 6. DIGITAL SECTION ...................................................................... 32  Logic Levels ................................................................................. 32 6.1.1. 1.8V Pins – Absolute Maximum Ratings ...................................... 32 6.1.2. 1.8V Standard GPIOs ................................................................... 32 6.1.3. 1.8V SIM Card Pins ...................................................................... 33 6.1.4. 2.85V Pins – Absolute Maximum Ratings .................................... 33 6.1.5. SIM Card Pins @2.85V ................................................................ 33  Power On ..................................................................................... 34 6.2.1. Initialization and Activation State .................................................. 34  Power Off ..................................................................................... 35  Unconditional Hardware Reset ..................................................... 36  Communication ports ................................................................... 37 6.5.1. USB Interface ............................................................................... 37 6.5.2. SIM Interface ................................................................................ 39 6.5.2.1. SIM Schematic Example .............................................................. 40 6.5.3. Control Signals ............................................................................. 41 6.5.3.1. W_DISABLE_N ............................................................................ 41 6.5.3.2. WAKE_N ...................................................................................... 41 6.5.3.3. WAN_LED_N ............................................................................... 42 6.5.4. General Purpose I/O .................................................................... 42 6.5.4.1. Using a GPIO Pin as Input ........................................................... 43 6.5.4.2. Using a GPIO Pin as Output ........................................................ 43 6.5.5. I2C – Inter-integrated circuit ......................................................... 43
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 7 of 68  2017-07-19   Using the Temperature Monitor Function ..................................... 44 7. RF SECTION ................................................................................ 45  Antenna requirements .................................................................. 45  Main Antenna Requirements ........................................................ 45  Antenna Diversity Requirements .................................................. 45  GNSS Receiver ............................................................................ 46 7.4.1. GNSS RF Front End Design......................................................... 46  Antenna connection ...................................................................... 47 7.5.1. Antenna Connector ...................................................................... 47 7.5.2. Antenna Cable .............................................................................. 48 7.5.3. Antenna Installation Guidelines .................................................... 48 8. AUDIO SECTION ......................................................................... 50  Audio Interface ............................................................................. 50  Digital Audio ................................................................................. 50 9. MECHANICAL DESIGN............................................................... 51  General ......................................................................................... 51  Finishing & Dimensions ................................................................ 51  Drawing ........................................................................................ 51 10. APPLICATION GUIDE ................................................................. 52  Debug of the LM940 Module in Production .................................. 52  Bypass Capacitor on Power Supplies .......................................... 52  EMC Recommendations .............................................................. 53 11. PACKAGING ............................................................................... 56  Tray .............................................................................................. 56 12. CONFORMITY ASSESSMENT ISSUES ..................................... 58  Approvals ..................................................................................... 58  Declaration of Conformity ............................................................. 58  FCC certificates ............................................................................ 58  IC certificates ................................................................................ 58  FCC/IC Regulatory notices ........................................................... 58 13. SAFETY RECOMMENDATIONS ................................................. 62  READ CAREFULLY ..................................................................... 62 14. REFERENCE TABLE OF RF BANDS CHARACTERISTICS ..... 63 15. ACRONYMS ................................................................................ 65
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 8 of 68  2017-07-19  16. DOCUMENT HISTORY ................................................................ 67
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 9 of 68  2017-07-19  1.  INTRODUCTION   Scope This  document  introduces  the  Telit  LM940  module  and  presents  possible  and recommended hardware solutions for developing a product based on the LM940 module. All the features and solutions detailed in this document are applicable to all LM940 variants, where “LM940” refers to the variants listed in the Applicability Table. If a specific feature is applicable to a specific product only, it will be clearly marked.   Information  –  LM940  refers  to  all  modules  listed  in  the  Applicability Table.  This  document  takes  into  account  all  the  basic  functions  of  a  wireless  module;  a  valid hardware  solution  is  suggested  for  each  function,  and  incorrect  solutions  and  common errors to be avoided are pointed out. Obviously, this document cannot embrace every hardware solution or every product that can be designed. Where the suggested hardware configurations need not be considered mandatory, the information given should be used as a guide and a starting point for properly developing your product with the Telit LM940 module.   Information  –  The  integration  of  the  WCDMA/HSPA+/LTE  LM940 cellular module  within a user application must  be  done according to the design rules described in this manual.     Audience This  document  is  intended  for  Telit  customers,  especially  system  integrators,  about  to implement their applications using the Telit LM940 module.    Contact Information, Support For  general  contact,  technical  support  services,  technical  questions  and  report documentation errors contact Telit Technical Support at:    TS-EMEA@telit.com   TS-AMERICAS@telit.com  TS-APAC@telit.com   TS-SRD@telit.com
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 10 of 68  2017-07-19  Alternatively, use: http://www.telit.com/en/products/technical-support-center/contact.php  For detailed information about where you can buy the Telit modules or for recommendations on accessories and components visit: http://www.telit.com  To register for product news and announcements or for product questions contact Telit’s Technical Support Center (TTSC). Our aim is to make this guide as helpful as possible. Keep us informed of your comments and suggestions for improvements. Telit appreciates feedback from the users of our information.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 11 of 68  2017-07-19    Text Conventions   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.     Tip  or  Information  –  Provides  advice  and  suggestions  that  may  be useful when integrating the module.   All dates are in ISO 8601 format, i.e. YYYY-MM-DD.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 12 of 68  2017-07-19    Related Documents   LM940 SW User Guide, 1VV0301343   LM940 AT Commands Reference Guide, 80545ST10791A   Generic EVB HW User Guide, 1VV0301249   LM940 Interface Board HW User Guide, 1VV0301384   SIM Integration Design Guide Application Note Rev10, 80000NT10001A   Antenna Detection Application Note, 80000NT10002A
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 13 of 68  2017-07-19  2.  GENERAL PRODUCT DESCRIPTION  Overview The aim of this document is to present possible and recommended hardware solutions useful for developing a product with the Telit LM940 Mini PCIe module. LM940 is Telit’s platform for Mini PCIe module for applications, such as M2M applications, industrial mobile router and table PC, based on the following technologies:    LTE / WCDMA networks for data communication   Designed for industrial grade quality  In its most basic use case, LM940 can be applied as a wireless communication front-end for mobile router products, offering mobile communication features to an external host CPU through its rich interfaces. LM940 can further support customer software applications and security features. LM940 provides a software application development environment with sufficient system resources for creating rich on-board applications. Thanks to a dedicated application processor and embedded security resources, product developers and manufacturers can create products that guarantee fraud prevention and tamper evidence without extra effort for additional security precautions.   LM940 is available in hardware variants as listed in Applicability Table The designated RF band sets per each variant are detailed in Section 2.2,  Product Variants and Frequency Bands.    Product Variants and Frequency Bands The operating frequencies in LTE & WCDMA modes conform to the 3GPP specifications. 2.2.1.  RF Bands per Regional Variant This table summarizes the LM940, showing the supported band sets and the supported band pairs and triple for carrier aggregation. RF Bands and Carrier Aggregation  LTE FDD  LTE TDD  HSPA+ Bands  1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 20, 25, 26, 28, 29, 30, 66 38, 40, 41  1, 2, 4, 5, 8 GNSS  GPS, GLONASS, BeiDou, Galileo LTE 2DL carrier aggregation combinations North America B2+B2, B2+B4, B2+B5, B2+B12, B2+B13, B2+B17, B2+B29, B2+B30, B4+B4, B4+B5, B4+B7, B4+B12, B4+B13, B4+B17, B4+B29, B4+B30, B5+B30, B12+B12, B12+B30, B25+B25, B25+B26, B25+B41, B26+B41, B29+B30, B41+B41 Europe  B1+B20, B3+B3, B3+B7, B3+B20, B3+B38, B7+B7, B7+B8, B7+B20, B38+B38
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 14 of 68  2017-07-19  Australia  B1+B3,  B1+B7, B1+B28, B3+B8, B3+B28, B5+B7, B5+B40, B7+B8, B7+B20 LTE 3DL carrier aggregation combinations North America B2+B2+B12/17, B2+B2+B13, B2+B2+B4, B2+B4+B5, B2+B4+B12, B2+B4+B13, B2+B4+B29, B2+B5+B30, B2+B12+B12, B2+B12+B30, B2+B29+B30, B4+B4+B5, B4+B4+B7, B4+B4+B12, B4+B4+B13, B4+B5+B30, B4+B12+B12, B4+B12+B30, B4+B29+B30, B25+B26+B41, B25+B41+B41, B26+B41+B41, B41+B41+B41 Europe  B1+B3+B20, B1+B7+B20, B3+B3+B7, B3+B3+B20, B3+B7+B20, B3+B7+B7, B3+B20+B38, B3+B38+B38 Australia  B3+B3+B5, B3+B3+B8, B3+B7+B7,  B3+B7+B28, B7+B7+B28, B28+B40+B40, B40+B40+B40 Refer to Chapter 13 for details information about frequencies and bands.    Target market LM940  can  be  used for  telematics  applications  where  tamper-resistance,  confidentiality, integrity, and authenticity of end-user information are required, for example:   Mobile router   Industrial equipment   Home network   Internet connectivity   Main features The LM940 family of industrial grade cellular modules features LTE and multi-RAT module together with an on-chip powerful application processor and a rich set of interfaces. The major functions and features are listed below. Main Features Function  Features Module    Multi-RAT  cellular module for data communication o  LTE FDD/TDD Cat11(600/75 Mbps DL/UL) o  WCDMA up to DC HSPA+, Rel.9   Support for GPS, GLONASS, BeiDou, Galileo Audio subsystem   Support digital audio interface (optional)
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 15 of 68  2017-07-19  Function  Features Two USIM ports – dual voltage   Support for dual SIM   Class B and Class C support    Clock rates up to 4 MHz  Application processor Application processor to run customer application code    32 bit ARM Cortex-A7 up to 1.19 GHz running the Linux operating system   4Gbit NAND Flash + 2Gbit LPDDR2 MCP is supported to allow for customer’s own software applications Interfaces   Rich set of interfaces, including:    USB2.0 / USB3.0 – USB port is typically used for: o  Flashing of firmware and module configuration o  Production testing o  Accessing the Application Processor’s file system o  AT command access o  High-speed WWAN access to external host o  Diagnostic monitoring and debugging o  Communication between Java application environment and an external host CPU o  NMEA data to an external host CPU   Peripheral Ports – GPIOs Major software features   Advanced security features o  Boot integrity of firmware up to customer applications o  Disable/secure re-enable of debug o  Embedded security   FOTA (optional)    Telit Unified AT command set Form factor  Mini PCIe Form factor (50.95x30x2.7mm), accommodating the multiple RF bands
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 16 of 68  2017-07-19  Function  Features Environment and quality requirements The entire module is designed and qualified by Telit for satisfying the environment and quality requirements for use in applications1. Single supply module The module generates all its internal supply voltages. RTC  The real-time clock is supported. Operating temperature Range -40 °C to +85 °C  (conditions as defined in Section 2.9.1, Temperature Range)    Block Diagram Below figure shows an overview of the internal architecture of the LM940 module.   LM940 Block Diagram   It includes the following sub-functions:   Application processor, Module subsystem and Location processing with their external interfaces. These three functions are contained in a single SOC.   RF front end                                                  1InaccordancewithTelit’sRobustnessValidation,usingAEC‐Q100‐definedqualificationtests
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 17 of 68  2017-07-19    Rich IO interfaces. Depending on which LM940 software features are enabled, some of its interfaces that are exported through multiplexing may be used internally and thus may not be usable by the application.   PMIC with the RTC function inside     TX Output Power  Band  Power class 3G WCDMA  Class 3 (0.2W) LTE All Bands  Class 3 (0.2W)    RX Sensitivity Below the 3GPP measurement conditions used to define the RX sensitivity: Technology  3GPP Compliance 4G LTE  Throughput >95% 10MHz Dual Receiver 3G WCDMA  BER <0.1% 12.2 Kbps Dual Receiver  Product  Band  Typical Rx Sensitivity (dBm) * / ** (LTE BW = 10 MHz) LM940  LTE FDD B1 LTE FDD B2 LTE FDD B3 LTE FDD B4 LTE FDD B5 LTE FDD B7 LTE FDD B8 LTE FDD B12 LTE FDD B13 LTE FDD B17 LTE FDD B20 -101.5 -101.0 -101.5 -101.0 -102.5 -99.5 -102.5 -102.0 -102.0 -102.0 -102.0
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 18 of 68  2017-07-19  LTE FDD B25 LTE FDD B26 LTE FDD B28 LTE FDD B30 LTE FDD B66 LTE TDD B38 LTE TDD B40 LTE TDD B41 -101.0 -102.0 -102.0 -100.5 -101.0 -100.0 -100.0 -99.5 LM940  WCDMA FDD B1 WCDMA FDD B2 WCDMA FDD B4 WCDMA FDD B5 WCDMA FDD B8 -108.5 -108.5 -108.5 -109.5 -109.5 * LTE Rx Sensitivity shall be verified by using both (all) antenna ports simultaneously.** 3.3 Voltage / Room temperature   Mechanical specifications 2.8.1.  Dimensions  The LM940 module’s overall dimensions are:    Length: 50.95 mm, +/- 0.15 mm tolerance   Width: 30.00 mm, +/- 0.15 mm tolerance   Thickness: 2.70 mm, +/- 0.15 mm tolerance 2.8.2.  Weight  The nominal weight of the LM940 module is 9.6 gram.    Environmental Requirements 2.9.1.  Temperature Range   Note Operating Temperature Range –20°C ~ +55°C This  range  is  defined  by  3GPP  (the  global standard for wireless mobile communication). Telit guarantees its modules to comply with all the  3GPP  requirements  and  to  have  full functionality of the module with in this range.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 19 of 68  2017-07-19    Note –40°C ~ +85°C Telit  guarantees  full  functionality  within  this range  as  well.  However,  there  may  possibly be  some  performance  deviations  in  this extended  range  relative  to  3GPP requirements,  which  means  that  some  RF parameters  may  deviate  from  the  3GPP specification  in  the  order  of  a  few  dB.  For example:  receiver  sensitivity  or  maximum output power may be slightly degraded.  Even  so,  all  the  functionalities,  such  as  call connection,  SMS,  USB  communication, UART activation etc., will be maintained, and the effect of such degradations will not lead to malfunction. Storage and non-operating Temperature Range –40°C ~ +85°C   2.9.2.  RoHS Compliance As a part of the Telit corporate policy of environmental protection, the LM940 complies with the RoHS (Restriction of Hazardous Substances) directive of the European Union (EU directive 2011/65/EU).
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 20 of 68  2017-07-19  3.  PINS ALLOCATION  Pin-out LM940 Pin-out Pin  Signal  I/O  Function  Type  Comment USB HS 2.0 Communication Port 38  USB_D+  I/O  USB 2.0 Data Plus  Analog   36  USB_D-  I/O  USB 2.0 Data Minus  Analog   USB SS 3.0 Communication Port 25  USB_SS_TX_P O USB 3.0 super-speed transmit – plus Analog   23  USB_SS_TX_M O USB 3.0 super-speed transmit – minus Analog   33  USB_SS_RX_P I USB 3.0 super-speed receive – plus Analog   31  USB_SS_RX_M I USB 3.0 super-speed receive – minus Analog   SIM Card Interface 1 8  SIMVCC1  O  Supply output for an external UIM1 card 1.8V / 2.85V Power 10  SIMIO1  I/O  Data connection with an external UIM1 card 1.8V / 2.85V  12  SIMCLK1  O  Clock output to an external UIM1 card 1.8V / 2.85V  14  SIMRST1  O  Reset output to an external UIM1 card 1.8V / 2.85V
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 21 of 68  2017-07-19  SIM Card Interface 2 13  SIMVCC2  O  Supply output for an external UIM2 card 1.8 / 2.85V  Power 19  SIMIO2  I/O  Data connection with an external UIM2 card 1.8 / 2.85V   17  SIMCLK2  O  Clock output to an external UIM2 card 1.8 / 2.85V   7  SIMRST2  O  Reset output to an external UIM2 card 1.8 / 2.85V   Digital I/O (GPIOs) 3  GPIO_01   I/O  General purpose I/O, SIMIN1  depending on product 1.8V   5  GPIO_02   I/O  General purpose I/O, SIMIN2 depending on product 1.8V   44  GPIO_03   I/O  General purpose I/O  1.8V   46  GPIO_04  I/O  General purpose I/O  1.8V   Control Signal 1  WAKE_N  O  Host wake-up  1.8V   20  W_DISABLE_N  I  RF disable  1.8V   42  WAN_LED_N  O  LED control  1.8V   Miscellaneous Functions 11  VREG_L6_1P8  O  Reference Voltage  1.8V  Power
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 22 of 68  2017-07-19  22  SYSTEM_RESET_N  I  Reset Input  1.8V   Digital Audio Interface 45  DVI _CLK  O  PCM Clock  1.8V   47  DVI _TX  O  PCM Data Out  1.8V   49  DVI _RX  I  PCM Data In  1.8V   51  DVI _WAO  O  PCM Frame Sync  1.8V   I2C Interface 30  I2C_SCL  O  I2C Clock  1.8V   32  I2C_SDA  I/O  I2C Data  1.8V   Power Supply 2  VBATT  I  Power supply  Power   24  VBATT  I  Power supply  Power   39  VBATT  I  Power supply  Power   41  VBATT  I  Power supply  Power   52  VBATT  I  Power supply  Power   GROUND 4  GND  -  Ground  Ground   9  GND  -  Ground  Ground   15  GND  -  Ground  Ground   18  GND  -  Ground  Ground
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 23 of 68  2017-07-19     Information – If the DVI and I2C interface are not used, the signals can be left floating.   21  GND  -  Ground  Ground   26  GND  -  Ground  Ground   27  GND  -  Ground  Ground   29  GND  -  Ground  Ground   34  GND  -  Ground  Ground   35  GND  -  Ground  Ground   37  GND  -  Ground  Ground   40  GND  -  Ground  Ground   43  GND  -  Ground  Ground   50  GND  -  Ground  Ground   Reserved 6  Reserved  -  Reserved (NC)     16  Reserved  -  Reserved (NC)     28  Reserved  -  Reserved (NC)     48  Reserved  -  Reserved (NC)
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 24 of 68  2017-07-19    Information – Unless otherwise specified, RESERVED  pins  must  be left unconnected (Floating).     LM940 Signals That Must Be Connected Below table specifies the LM940 signals that must be connected for a debugging purpose even if not used by the end application: Mandatory Signals Pin  Signal  Notes 2, 24, 39, 41, 52  VBATT    4, 9, 15, 18, 21, 26, 27, 29, 34, 35, 37, 40, 43, 50 GND   38  USB_D+  If not used, connect to a test point or an USB connector 36  USB_D-  If not used, connect to a test point or an USB connector
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 25 of 68  2017-07-19    Pin Layout
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 26 of 68  2017-07-19  4.  POWER SUPPLY  The power supply circuitry and board layout are very important parts of the full product design, with critical impact on the overall product performance. Read the following requirements and guidelines carefully to ensure a good and proper design.    Power Supply Requirements The LM940 power requirements are as follows: Power Supply Requirements Nominal supply voltage  3.3V Supply voltage range  3.10V – 3.6V Maximum ripple on module input supply  30 mV    Power Consumption Below table provides typical current consumption values of LM940 for various operation modes. LM940 Current Consumption Mode  Average [Typ.]  Mode Description IDLE Mode IDLE Mode  60.0 mA  No call connection USB3.0 is connected to a host  Operative Mode (LTE) LTE (22 dBm)  750 mA  LTE data call (Non-CA BW 5MHz, RB=1)   1250 mA LTE data call (CA_3A+7A+20A, 20MHz+20MHz+20MHz, Full RB, 256QAM DL / 64QAM UL, FDD 600Mbps DL / 75Mbps UL) Operative Mode (WCDMA) WCDMA Voice  650 mA  WCDMA voice call (Tx = 23 dBm)WCDMA HSPA (22 dBm)  650 mA  WCDMA data call (DC-HSDPA up to 42 Mbps, Max Throughput) * Worst/best case current values depend on network configuration - not under module control. ** Applied MPR –2dB 16-QAM full RB *** 3.3 voltage / room temperature
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 27 of 68  2017-07-19    Information – The electrical design for the power supply must ensure a peak current output of at least 2A.     General Design Rules The principal guidelines for the Power Supply Design embrace three different design steps:   Electrical design   Thermal design   PCB layout 4.3.1.  Electrical Design Guidelines The electrical design of the power supply depends strongly on the power source where this power is drained.  4.3.1.1.  + 5V Input Source Power Supply – Design Guidelines   The desired output for the power supply is 3.8V. So, the difference between the input source and the desired output is not big, and therefore a linear regulator can be used. A switching power supply is preferred to reduce power consumption.  When using a linear regulator, a proper heat sink must be provided to dissipate the power generated.  A bypass low ESR capacitor of adequate capacity must be provided to cut the current absorption peaks close to the LE925A4 module. A 100 μF tantalum capacitor is usually suitable (on both VPH_PWR and VPH_PWR_RF together).  Make sure that the low ESR capacitor on the power supply output (usually a tantalum one) is rated at least 10V.  A protection diode must be inserted close to the power input to protect the LE925A4 module from power polarity inversion.Figure  shows an example of linear regulator with 5V input.      4.3.2.  Thermal Design Guidelines The thermal design for the power supply heat sink must be done with the following specifications:
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 28 of 68  2017-07-19    Average current consumption during RF transmission @PWR level max in LM940 as shown in Section 4.2, Power Consumption table.   Information – The average consumption during transmission depends on the power level at which the device is requested to transmit via the network.  Therefore, the average current consumption varies significantly.     Information – The thermal design for the power supply must be made keeping an  average consumption at  the maximum  transmitting level during calls of LTE/HSPA.   Considering the very low current during Idle, especially if the Power Saving function is enabled, it is possible to consider from the thermal point of view that the device absorbs significant current only during Data session.  In LTE/WCDMA/HSPA mode, the LM940 emits RF signals continuously during transmission. Therefore, you must pay special attention how to dissipate the heat generated. While designing the application board, the designer must make sure that the LM940 module is located on a large ground area of the application board for effective heat dissipation.    Information – The LM940 must be connected to the ground and metal chassis  of  the  host  board  for  best  RF  performance  and  thermal dispersion as well as to have module fixed.   The two holes at the top of the module and the main ground of the host board must be fastened together.   The shield cover of the module and the main board of the host board or the metal chassis of the host device should be connected with conductive materials.   4.3.3.  Power Supply PCB layout Guidelines As seen in the electrical design guidelines, the power supply must have a low ESR capacitor on the output to cut the current peaks and a protection diode on the input to protect the supply from spikes and polarity inversion. The placement of these components
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 29 of 68  2017-07-19  is crucial for the correct operation of the circuitry. A misplaced component can be useless or can even decrease the power supply performances.   The bypass low ESR capacitor must be placed close to the LM940 power input pins, or if the power supply is of a switching type, it can be placed close to the inductor to cut the ripple, as long as the PCB trace from the capacitor to LM940 is wide enough to ensure a drop-less connection even during the 2A current peaks.   The protection diode must be placed close to the input connector where the power source is drained.   The PCB traces from the input connector to the power regulator IC must be wide enough to ensure that no voltage drops occur during the 2A current peaks.    The PCB traces to LM940 and the bypass capacitor must be wide enough to ensure that no significant voltage drops occur when the 2A current peaks are absorbed. This is needed for the same above-mentioned reasons. Try to keep these traces as short as possible.   The PCB traces connecting the switching output to the inductor and the switching diode must be kept as short as possible by placing the inductor and the diode very close to the power switching IC (only for the switching power supply). This is done to reduce the radiated field (noise) at the switching frequency (usually 100-500 kHz).   Use a good common ground plane.   Place the power supply on the board in a way to guarantee that the high current return paths in the ground plane do not overlap any noise sensitive circuitry, such as the microphone amplifier/buffer or earphone amplifier.   The power supply input cables must be kept separate from noise sensitive lines, such as microphone/earphone cables.   RTC The RTC within the LM940 module does not have a dedicated RTC supply pin. The RTC block is supplied by the VBATT supply. If VBATT power is removed, RTC is not maintained so if maintaining an internal RTC is needed, VBATT must be supplied continuously.    Reference Voltage 1.8V regulated power supply output is provided as the reference voltage to a host board. This output is active when the module is ON and goes OFF when the module is shut down. This table lists the VREG_L6_IP8 signal of LM940. LM940 Reference Voltage PIN  Signal  I/O  Function  Type  Comment 11  VREG_L6_1P8  O  Reference Voltage  power  1.8V
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 30 of 68  2017-07-19    Internal LDO for GNSS bias The LDO for GNSS bias is applied inside the LM940 model. The voltage supply come from LM940’s LDO to GNSS active antenna. This table lists the LDO for GNSS bias of LM940. LM940 Reference Voltage Symbol  Parameter  Min  Typ  Max  Unit VGNSS DC bias  Voltage of Internal LDO for GNSS bias  2.9  3.1  3.3  [V] IGNSS DC bias  Current of Internal LDO for GNSS bias  -  -  50  [mA]
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 31 of 68  2017-07-19  5.  ELECTRICAL SPECIFICATIONS    Absolute Maximum Ratings – Not Operational   Caution  –  A  deviation  from  the  value  ranges  listed  below  may harm the LM940 module.  Absolute Maximum Ratings – Not Operational Symbol  Parameter  Min  Max  Unit VBATT  Battery supply voltage on pin VBATT  -0.5  +4.0  [V]    Recommended Operating Conditions Recommended Operating Conditions Symbol  Parameter  Min  Typ  Max  Unit Tamb  Ambient temperature  -40  +25  +85  [°C] VBATT  Battery supply voltage on pin VBATT  3.1  3.3  3.6  [V] IVBATT +  IVBATT_PA Peak current to be used to dimension decoupling capacitors on pin VBATT  -  80  2500  [mA]
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 32 of 68  2017-07-19  6.  DIGITAL SECTION    Logic Levels Unless otherwise specified, all the interface circuits of the LM940 are 1.8V CMOS logic. Only USIM interfaces are capable of dual voltage I/O. The following tables show the logic level specifications used in the LM940 interface circuits. The data specified in the tables below is valid throughout all drive strengths and the entire temperature ranges.   Caution – Do not connect LM940’s digital logic signal directly to OEM’s digital logic signal with a level higher than 2.3V for 1.8V CMOS signals.   6.1.1.  1.8V Pins – Absolute Maximum Ratings Absolute Maximum Ratings – Not Functional Parameter  Min  Max Input level on any digital pin when on  --  +2.16V Input voltage on analog pins when on  --  +2.16 V  6.1.2.  1.8V Standard GPIOs Operating Range – Interface Levels (1.8V CMOS) Parameter  Min  Max  Unit  Comment VIH  Input high level  1.17V  2.1V  [V]   VIL  Input low level  -0.3V  0.63V  [V]   VOH  Output high level  1.35V  1.8V  [V]   VOL  Output low level  0V  0.45V  [V]   IIL  Low-level input leakage current -1  --  [uA]  No pull-up IIH  High-level input leakage current --  1  [uA]  No pull-down IILPU  Low-level input leakage current -97.5  -27.5  [uA]  With pull-up
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 33 of 68  2017-07-19  Parameter  Min  Max  Unit  Comment IIHPD  High-level input leakage current 27.5  97.5  [uA]  With pull-down CI/o  I/O capacitance  --  5  [pF]    6.1.3.  1.8V SIM Card Pins Operating Range – SIM Pins Working at 1.8V Parameter  Min  Max  Unit  Comment VIH  Input high level  1.26V  2.1V  [V]   VIL  Input low level  -0.3V  0.36V  [V]   VOH  Output high level  1.44V  1.8V  [V]   VOL  Output low level  0V  0.4V  [V]   IIL  Low-level input leakage current --  1000  [uA]  No pull-up IIH  High-level input leakage current -20  20  [uA]  No pull-down  6.1.4.  2.85V Pins – Absolute Maximum Ratings Absolute Maximum Ratings – Not Functional Parameter  Min  Max Input level on any digital pin when on  --  +3.42V Input voltage on analog pins when on  --  +3.42 V  6.1.5.  SIM Card Pins @2.85V Operating Range – For SIM Pins Operating at 2.85V Parameter  Min  Max  Unit  Comment VIH  Input high level  1.995V  3.15V  [V]   VIL  Input low level  -0.3V  0.57V  [V]   VOH  Output high level  2.28V  2.85V  [V]   VOL  Output low level  0V  0.4V  [V]
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 34 of 68  2017-07-19  Parameter  Min  Max  Unit  Comment IIL  Low-level input leakage current --  1000  [uA]  No pull-up IIH  High-level input leakage current -20  20  [uA]  No pull-down    Power On The LM940 is automatically turning on when the VBATT is supplied.   Information – To turn on the LM940 module, the W_DISABLE_N pin must not be asserted low.   6.2.1.  Initialization and Activation State After turning on the LM940 module, the LM940 is not yet activated because the SW initialization process of the LM940 module is still in process internally. It takes some time to fully complete the HW and SW initialization of the module. For this reason, it is impossible to access LM940 during the Initialization state. As shown in below figure, the LM940 becomes operational (in the Activation state) at least 15 seconds after the VBATT is supplied.  LM940 Initialization and Activation InitializationState ActivationStateInternalStateVREG_L6_1P8W_DISABLE_NOFFStateTBDsecUSBDriverLoadedAllInterfacesAndPinsConfiguredVBATTTBDsec
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 35 of 68  2017-07-19    Information  –  To  check  if  the  LM940  has  completely  powered  on, LM940 and the host must be connected via USB. When USB driver completely  loaded,  the  module  has  completely  powered  on  and  is ready to accept AT commands.  Information – During SW initialization of the LM940, the SW configures all  pins  and  interfaces  to their  desired  mode. When  VREG_L6_1P8 goes  high,  this  indicates  that  the  initialization  of  all  I/O  pins  is completed.  Information – Active low signals are labeled with a name that ends with “_N”     Information – To avoid a back-powering effect, it is recommended to avoid having any HIGH logic level signal applied to the digital pins of the module when it is powered OFF or during an ON/OFF transition.     Power Off  The LM940 module can be shut down by a software command. When a shutdown command is sent, LM940 goes into the Finalization state and at the end of the finalization process shuts down VREG_L6_1P8. The duration of the finalization state can differ according to the current situation of the module, so a value cannot be defined. Usually, it will take more than 12 seconds from sending a shutdown command until reaching a complete shutdown. The DTE should monitor the status of VREG_L6_1P8 to observe the actual power-off.   Information  –  To  completely  shut  down  the  LM940  module,  the W_DISABLE_N pin must be asserted low. Otherwise, the LM940 will turn on again after shut down.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 36 of 68  2017-07-19    Information – To avoid a back-powering effect, it is recommended to avoid having any HIGH logic level signal applied to the digital pins of the module when it is powered OFF or during an ON/OFF transition.   Shutdown by Software Commnad FinalizationState OFFStateInternalStateVREG_L6_1P8VPH_PWRActivationStateAT#SHDNVariableAboveTBDsecMonitoringStatusW_DISABLE_NMustBeAssertedLow.    Unconditional Hardware Reset To unconditionally restart the LM940 module, the SYSTEM_RESET_N pin must be asserted low for a between 100 milliseconds and 150milliseconds then released. Below figure shows a simple circuit for this action. Circuit for Unconditional Hardware Reset GNDR1R2Q1UnconditionalResetImpulse100 ms<HoldTime<150msSYSTEM_RESET_N   Information – The Unconditional Hardware Reset must be used only as  an  emergency  exit  procedure,  and  not  as  a  normal  power-off operation.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 37 of 68  2017-07-19    Information – Do not use any pull-up resistor on the RESET_N line or any totem pole digital output. Using a pull-up resistor may cause latch-up problems on the LM940 power regulator and improper functioning of the module. The RESET_N line must be connected only in an open-collector configuration.     Communication ports Below table summarizes all the hardware interfaces of the LM940 module. LM940 Hardware Interfaces  6.5.1.  USB Interface The LM940 module includes super-speed USB3.0 with high-speed USB2.0 backward compatibility. It is compliant with Universal Serial Bus Specification, Revision 3.0 and can be used for control and data transfers as well as for diagnostic monitoring and firmware update. The USB port is typically the main interface between the LM940 module and OEM hardware. USB 3.0 needs series capacitors on the TX lines in both directions for AC coupling. In order to interface USB3.0 with an application board of customer, 0.1uF capacitors should be installed on USB_SS_RX_P/M lines of the LM940. There are already series capacitors on USB_SS_TX_P/M lines inside LM940 module.  The USB interface suggested connection is the following: Connection for USB Interface Interface  LM940 USB  Super-speed USB3.0 with high-speed USB2.0 USIM  x2, dual voltage each (1.8V/2.85V) Control Signals  W_DISABLE_N, WAKE_N, WAN_LED_N GPIO  X4, GPIO I2C  I2C (optional) Audio I/F  PCM (optional) Antenna ports  2 for Cellular, 1 for GNSS
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 38 of 68  2017-07-19     Information  –  The  USB  signal  traces  must  be  routed  carefully. Minimize trace  lengths,  number  of  vias, and  capacitive  loading. The impedance  value  should  be  as  close  as  possible  to  90  Ohms differential.   Below table lists the USB interface signals. USB Interface Signals PIN  Signal  I/O  Function  Type  Comment 38  USB_D+  I/O  USB 2.0 Data Plus  Analog    36  USB_D-  I/O  USB 2.0 Data Minus  Analog    33  USB_SS_RX_P  I  USB 3.0 super-speed receive – plus  Analog   31  USB_SS_RX_M  I  USB 3.0 super-speed receive – minus  Analog   25  USB_SS_TX_P  O  USB 3.0 super-speed transmit – plus  Analog   23  USB_SS_TX_M  O  USB 3.0 super-speed transmit – minus  Analog      Information – Even if USB communication is not used, it is still highly recommended to place an optional USB connector on the application board. At  least  test  points  of  the  USB  signals  are  required  since  the  USB physical communication is needed in the case of SW update.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 39 of 68  2017-07-19    Information  –  Consider  placing  a  low-capacitance  ESD  protection component to protect LM940 against ESD strikes    If an ESD protection should be added, the suggested connectivity is as follows: ESD Protection for USB2.0   ESD Protection for USB3.0   6.5.2.  SIM Interface The LM940 supports two external SIM interfaces (1.8V or 2.85V).  Below table lists the SIM interface signals.  SIM Interface Signals PIN Signal I/O Function Type Comment SIM Card Interface 1
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 40 of 68  2017-07-19   6.5.2.1.  SIM Schematic Example The following Figures illustrate in particular how the application side should be designed.  SIM Schematics  SIM_CARDLM940SIMIOSIMCLKSIMRSTSIMVCC C1C2C3C5C6C712345678C1C2C3C4...33pF(DNI)33pF(DNI)33pF(DNI)100nF.SIMIN 8 SIMVCC1 O Supply output for an external UIM1 card 1.8V / 2.85V Power 10 SIMIO1 I/O Data connection with an external UIM1 card 1.8V / 2.85V  12 SIMCLK1 O Clock output to an external UIM1 card 1.8V / 2.85V  14 SIMRST1 O Reset output to an external UIM1 card 1.8V / 2.85V  SIM Card Interface 2 13 SIMVCC2 O Supply output for an external UIM2 card 1.8 / 2.85V Power 19 SIMIO2 I/O Data connection with an external UIM2 card 1.8 / 2.85V  17 SIMCLK2 O Clock output to an external UIM2 card 1.8 / 2.85V  7 SIMRST2 O Reset output to an external UIM2 card 1.8 / 2.85V  Digital I/O (GPIOs) 3 GPIO_01 I UIM1 Card Present Detect 1.8V GPIO_01 can be used as  SIMIN1 5 GPIO_02 I UIM2 Card Present Detect 1.8V GPIO_02 can be used as  SIMIN2
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 41 of 68  2017-07-19    Information – LM940 contains an internal pull-up resistor on SIMIO. It is not necessary to install external pull – up resistor.  6.5.3.  Control Signals The LM940 supports the following control signals:   W_DISABLE_N  WAKE_N   WAN_LED_N  Below table lists the control signals of LM940. Module Control Signal PIN  Signal  I/O  Function  Type  Comment 20  W_DISABLE_N  I  RF disable (airplane mode)  1.8V   1  WAKE_N  O  Host wake-up  1.8V   42  WAN_LED_N  O  LED control  1.8V    6.5.3.1.  W_DISABLE_N The W_DISABLE_N signal is provided to make the LM940 goes into the airplane mode:   Enter into the airplane mode: Low    Normal operating mode: High or Leave the W_DISABLE_N not connected The W_DISABLE_N should be controlled when the LM940 to either turn on or off.   6.5.3.2.  WAKE_N The WAKE_N signal wakes the host when specific events occur. Recommended WAKE_N connection is the following: Recommended WAKE_N connection LM940WAKE_NOpencollectorHostInputR1VCC
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 42 of 68  2017-07-19  6.5.3.3.  WAN_LED_N The WAN_LED_N signal drives the LED output. The recommended WAN_LED_N connection is the following: Recommended WAN_LED_N connection   6.5.4.  General Purpose I/O The general-purpose I/O pins can be configured to act in three different ways:   Input   Output   Dedicate Function (Customer Requirement) Input pins can only be read and report digital values (high or low) present on the pin at the read time. Output pins can only be written or queried and set the value of the pin output.  The following GPIOs are always available as a primary function on the LM940. Below table lists the GPIO signals of LM940. GPIOs Pin no.  Signal  I/O  Function  Type  Drive Strength 3  GPIO_01  I/O  Configurable GPIO CMOS 1.8V 2-16 mA 5  GPIO_02  I/O  Configurable GPIO CMOS 1.8V 2-16 mA 44  GPIO_03   I/O  Configurable GPIO CMOS 1.8V 2-16 mA 46  GPIO_04  I/O  Configurable GPIO CMOS 1.8V 2-16 mA
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 43 of 68  2017-07-19  6.5.4.1.  Using a GPIO Pin as Input GPIO pins, when used as inputs, can be tied to a digital output of another device and report its status, provided the device interface levels are compatible with the GPIO 1.8V CMOS levels.  If a digital output of a device is tied to GPIO input, the pin has interface levels different than 1.8V CMOS. It can be buffered with an open collector transistor with a 47 kΩ pull-up resistor to 1.8V.  6.5.4.2.  Using a GPIO Pin as Output GPIO pins, when used as outputs, can drive 1.8V CMOS digital devices or compatible hardware. When set as outputs, the pins have a push-pull output, and therefore the pull-up resistor can be omitted. GPIO Output Pin Equivalent Circuit   6.5.5.  I2C – Inter-integrated circuit The LM940 supports an I2C interface on the following pins: Below table lists the I2C signals of LM940.     Module I2C Signal PIN  Signal  I/O  Function  Type  Comment 30  I2C_SCL  O  I2C Clock  CMOS 1.8V   32  I2C_SDA  I/O  I2C Data CMOS 1.8V  The I2C interface is used for controlling peripherals inside the module (such as codec, etc.).
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 44 of 68  2017-07-19    Information  –  I2C  is  supported  only  on  from  Modem  side  as  SW emulation of I2C on GPIO lines. Please contact us if you use it.     Information – If the I2C interface is not used, the signals can be left floating.     Using the Temperature Monitor Function The Temperature Monitor permits to monitor the module’s internal temperature and, if properly set (see the #TEMPSENS command in LM940 AT Commands Reference Guide ), raises a GPIO to High Logic level when the maximum temperature is reached.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 45 of 68  2017-07-19  7.  RF SECTION    Antenna requirements The antenna connection is one of the most important aspect in the full product design as it strongly  affects  the  product  overall  performance.  Hence  read  carefully  and  follow  the requirements and the guidelines for a proper design. The LM940 is provided with three RF connectors.  The available connectors are:   Main RF antenna: TX/RX path   Auxiliary RF antenna: Combined Diversity and GNSS   GNSS RF antenna: Dedicated GNSS    Main Antenna Requirements The antenna for the LM940 device must meet the following requirements: WCDMA / LTE Antenna Requirements Frequency range  Depending by frequency band(s) provided by the network operator, the customer shall use the most suitable antenna for that/those band(s)  The bands supported by the LM940 is provided in Section 2.2,  Product Variants and Frequency Bands. Impedance  50 Ohm Input power  > 24 dBm average power in WCDMA & LTE VSWR absolute max  <= 10:1 VSWR recommended  <= 2:1    Antenna Diversity Requirements This product includes an input for a second Rx antenna to improve radio sensitivity. The function is called Antenna Diversity. Antenna Diversity Requirements Frequency range  Depending by frequency band(s) provided by the network operator, the customer shall use the most suitable antenna for that/those band(s)   The bands supported by the LM940 is provided in Section 2.2,  Product Variants and Frequency Bands. Impedance  50Ω VSWR recommended  ≤  2:1
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 46 of 68  2017-07-19  The second Rx antenna should not be located in the close vicinity of main antenna. In order to improve Diversity Gain, Isolation and reduce mutual interaction, the two antennas should be located at the maximum reciprocal distance possible, taking into consideration the available space into the application. For the same reason, the Rx antenna should also be cross-polarized with respect to the main antenna.  Isolation between main antenna and Rx antenna must be at least 10 dB in all uplink frequency bands.  Envelope Correlation Coefficient (ECC) value should be as close as possible to zero, for best diversity performance. ECC values below 0.5 on all frequency bands are recommended.    GNSS Receiver The LM940 integrates a GNSS receiver that could be used in Standalone mode and in A-GPS (assisted GPS), according to the different configurations.  LM940 supports an active antenna. Frequency range  • Wide-band GNSS: 1560–1606 MHz recommended • Narrow-band GPS: 1575.42 MHz ± 2 MHz minimum • Narrow-band Galileo: 1575.42 MHz ± 2 MHz minimum • Narrow-band BeiDou: 1561.098 MHz ± 2 MHz minimum • Narrow-band GLONASS: 1601.72 MHz ± 4.2 MHz minimum. Gain  1.5 dBi < Gain < 3 dBi Impedance  50 Ohm Amplification   18 dB < Gain < 21 dB Supply Voltage  3.1 V Current consumption  20 mA Typical  7.4.1.  GNSS RF Front End Design The LM940 contains an integrated LNA and pre-select SAW filter.  This allows the module to work well with a passive GNSS antenna. If the antenna cannot be located near the LM940, then an active antenna (that is, an antenna with a low noise amplifier built in) can be used with an external dedicated power supply circuit.  GNSS rescive path uses either the dedicated GNSS connector or the shared AUX connector.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 47 of 68  2017-07-19    NOTE – Please refer to the LM940 AT Commands Reference Guide, 80545ST10791A  for  detailed  information  about  GNSS  operating modes and GNSS Antenna selection.     Antenna connection 7.5.1.  Antenna Connector The LM940 is equipped with a set of 50 Ω RF U.FL. connectors from Hirose U.FL-R-SMT-1(10).   The available connectors are:   Main RF antenna: TX/RX path   Auxiliary RF antenna: Combined Diversity and GNSS   GNSS RF antenna: Dedicated GNSS  See the picture on the below for their position on the interface.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 48 of 68  2017-07-19  For more information about mating connectors visit the website http://www.hirose-connectors.com/  7.5.2.  Antenna Cable Connecting cables between the module and the antenna must have 50 Ω impedance.  If the impedance of the module is mismatched, RF performance is reduced significantly.  If the host device is not designed to use the module’s diversity or GNSS antenna, terminate the interface with a 50Ω load. Minimize Antenna Cable Requirements Impedance  50 Ohm Max cable loss  0.5 dB Avoid coupling with other signals.  7.5.3.  Antenna Installation Guidelines   Install the antenna in a location with access to the network radio signal.   The antenna must be installed such that it provides a separation distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any other antenna or transmitter.   The antenna must not be installed inside metal cases.    The antenna must be installed according to the antenna manufacturer’s instructions.  Furthermore, if the device is developed for the US and/or Canada market, it must comply with the FCC and/or IC approval requirements.  Information This device  is  to  be  used  only  for mobile and fixed application. The antenna(s)  used  for  this  transmitter  must  be  installed  to  provide  a separation distance of at least 20 cm from all persons and must not be co-located  or  operating  in  conjunction  with  any  other  antenna  or transmitter.  End-Users  must  be  provided  with  transmitter  operation conditions  for  satisfying  RF  exposure  compliance.  OEM  integrators must ensure that the end user has no manual instructions to remove or install the LM940 module. Antennas used for this OEM module must not  exceed  gain  of  below  table  for  mobile  and  fixed  operating configurations. In the event that these conditions cannot be met (for example certain laptop configurations or co-location with another transmitter), then the FCC/IC authorization is no longer considered valid and the FCC/IC ID cannot be used on the final product. In these circumstances, the OEM integrator  will  be  responsible  for  re-evaluating  the  end  product (including  the  transmitter)  and  obtaining  a  separate  FCC/IC authorization.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 49 of 68  2017-07-19    Manual Information to the End User  The OEM integrator has to be aware not to provide information to the end  user  regarding  how  to  install  or  remove  this  RF  module  in  the user’s manual of the end  product  which  integrates this module. The end  user  manual  shall  include  all  required  regulatory information/warning as show in this manual.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 50 of 68  2017-07-19  8.  AUDIO SECTION    Audio Interface The LM940 module supports digital audio interfaces.    Digital Audio The LM940 module can be connected to an external codec through the digital interface. The product provides a single Digital Audio Interface on the following pins: Digital Audio Interface Signals Pin no.  Signal  I/O  Function  Type  COMMENT 51  DVI_WAO  O  PCM Frame Sync  B-PD 1.8V   49  DVI_RX  I  PCM Data In  B-PD 1.8V   47  DVI _TX  O  PCM Data Out  B-PD 1.8V   45  DVI _CLK  O  PCM Clock  B-PD 1.8V    LM940 PCM has the following characteristics:   PCM Master mode using short or long frame sync modes   16 bit linear PCM format   PCM clock rates of 256 kHz, 512 kHz, 1024 kHz and 2048 kHz (Default)   Frame size of 8, 16, 32, 64, 128 & 256 bits per frame   Sample rates of 8 kHz and 16 kHz    NOTE – If the Digital Audio Interface is not used, the signals can be left floating.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 51 of 68  2017-07-19  9.  MECHANICAL DESIGN   General The LM940 module was designed to be compliant with a standard lead-free SMT process. Moreover, it is compatible with the Mini PCIe card 52-pin card edge-type connector.    Finishing & Dimensions The LM940 module’s overall dimensions are:    Length:     50.95 mm   Width:     30.00 mm   Thickness:  2.70 mm  The module complies with the standard dimensions specified in the PCI Express Mini Card Electromechanical Specification Revision 1.1   Drawing This figure shows the mechanical dimensions of the LM940 module.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 52 of 68  2017-07-19  10.  APPLICATION GUIDE   Debug of the LM940 Module in Production To test and debug the mounting of the LM940 module, we strongly recommend to add several test pins on the host PCB for the following purposes:   Checking the connection between the LM940 itself and the application   Testing the performance of the module by connecting it with an external computer Depending on the customer application, these test pins include, but are not limited to the following signals:   SYSTEM_RESET_N, W_DISABLE_N, WAKE_N   VBATT, GND   VREG_L6_1P8   USB_D-, USB_D+   USB_SS_TX_M, USB_SS_TX_P, USB_SS_RX_M, USB_SS_RX_P  In addition, the following signals are also recommended (but not mandatory):   WAN_LED_N   GPIO_01, GPIO_02, GPIO_03, GPIO_04    Bypass Capacitor on Power Supplies When a sudden voltage step is asserted to or a cut from the power supplies, the steep transition causes some reactions such as overshoot and undershoot. This abrupt voltage transition can affect the device causing it to not operate or to malfunction. Bypass capacitors are needed to alleviate this behavior. The behavior can appear differently depending on the various applications. Customers must pay special attention to this issue when they design their application board. The length and width of the power lines must be considered carefully, and the capacitance of the capacitors must be selected accordingly. The capacitor will also prevent ripple of the power supplies and the switching noise caused in TDMA systems such as GSM.  Especially, a suitable bypass capacitor must be mounted on the following lines on the application board:   VBATT Recommended values are:   100uF for VBATT Customers must still consider that the capacitance mainly depends on the conditions of their application board. Generally, more capacitance is required when the power line is longer. And if customers use the fast power down function, then more bypass capacitors should be mounted on the application board.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 53 of 68  2017-07-19    EMC Recommendations EMC protection on the pins in the table below should be designed by application side according to the customer’s requirement.  EMC Recommendations Pin  Signal  I/O  Function  Type  Comment USB HS 2.0 Communication Port 38  USB_D+  I/O  USB 2.0 Data Plus  Analog   36  USB_D-  I/O  USB 2.0 Data Minus  Analog   USB SS 3.0 Communication Port 33  USB_SS_RX_P  I  USB 3.0 super-speed receive – plus Analog   31  USB_SS_RX_M  I  USB 3.0 super-speed receive – minus Analog   25  USB_SS_TX_P O USB 3.0 super-speed transmit – plus Analog   23  USB_SS_TX_M O USB 3.0 super-speed transmit – minus Analog   SIM Card Interface 1 14  SIMRST1  O  Reset output to an external UIM1 card 1.8 / 2.85V   12  SIMCLK1  O  Clock output to an external UIM1 card 1.8 / 2.85V   10  SIMIO1  I/O  Data connection with an external UIM1 card 1.8 / 2.85V
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 54 of 68  2017-07-19  8  SIMVCC1  O  Supply output for an external UIM1 card 1.8 / 2.85V  Power SIM Card Interface 2 7  SIMRST2  O  Reset output to an external UIM2 card 1.8 / 2.85V   17  SIMCLK2  O  Clock output to an external UIM2 card 1.8 / 2.85V   19  SIMIO2  I/O  Data connection with an external UIM2 card 1.8 / 2.85V   13  SIMVCC2  O  Supply output for an external UIM2 card 1.8 / 2.85V  Power Digital I/O (GPIOs) 3  GPIO_01  I/O  General purpose I/O  1.8V   5  GPIO_02  I/O  General purpose I/O  1.8V   44  GPIO_03  I/O  General purpose I/O  1.8V   46  GPIO_04  I/O  General purpose I/O  1.8V   1  WAKE_N  O  Host wake-up  1.8V  Active Low 42  WAN_LED_N  O  LED control  1.8V   Power ON/OFF Reset IN/OUT 20  W_DISABLE_N  I  Module & RF ON/OFF Control 1.8V  Active Low 22  SYSTEM_RESET_N  I  Reset Input  1.8V  Active Low 1.8V Voltage Regulator 11  VREG_L6_1P8  O  LDO out for 1.8V  Power
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 55 of 68  2017-07-19  All other pins have the following characteristics: Human Body Model (HBM): ± 1000 V Charged Device Model (CDM) JESD22-C101-C: ± 250 V  All Antenna pins up to ± 4 kV    Warning  –  Do  not  touch  without  proper  electrostatic  protective equipment.  The  product  must  be  handled  with  care,  avoiding  any contact with the pins because electrostatic discharge may damage the product itself.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 56 of 68  2017-07-19  11.  PACKAGING   Tray The LM940 modules are packaged on trays of 20 pieces each. These trays can be used in SMT processes for pick & place handling.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 57 of 68  2017-07-19
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 58 of 68  2017-07-19  12.  CONFORMITY ASSESSMENT ISSUES   Approvals   Fully type approved confirming with R&TTE directive   CE, GCF   FCC, IC, PTCRB    RoHS and REACH   Approvals for major Mobile Network Operators    Declaration of Conformity  The DoC is available here: www.telit.com/RED/     FCC certificates The FCC Certifcate is available here: www.fcc.gov/oet/ea/fccid     IC certificates The IC Certifcate is available here:  https://sms-sgs.ic.gc.ca/equipmentSearch/searchRadioEquipments?execution=e1s1&lang=en     FCC/IC Regulatory notices Modification statement Telit has not approved any changes or modifications to this device by the user. Any changes or modifications could void the user’s authority to operate the equipment.  Telit n’approuve aucune modification apportée à l’appareil par l’utilisateur, quelle qu’en soit la nature. Tout changement ou modification peuvent annuler le droit d’utilisation de l’appareil par l’utilisateur.  Interference statement This device complies with Part 15 of the FCC Rules and Industry Canada licence-exempt RSS standard(s). Operation is subject to the following two conditions: (1) this device may not  cause  interference,  and  (2)  this  device  must  accept  any  interference,  including interference that may cause undesired operation of the device.  Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de licence. L'exploitation est autorisée aux deux conditions suivantes : (1) l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter tout
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 59 of 68  2017-07-19  brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le fonctionnement.  RF exposure This  equipment  complies  with  FCC  and  ISED  radiation  exposure  limits  set  forth  for  an uncontrolled  environment.  The  antenna  should  be  installed  and  operated  with  minimum distance of 20 cm between the radiator and your body. Antenna gain must be below:  Cet appareil est conforme aux limites d'exposition aux rayonnements de l’ISED pour un environnement non contrôlé. L'antenne doit être installé de façon à garder une distance minimale de 20 centimètres entre la source de rayonnements et votre corps. Gain de l'antenne doit être ci-dessous:  WCDMA / LTE Antenna (except Band 30)   Brand : HNS (HANKOOK Network Solution)   Model Number : WE14-LF-07   Type : Dipole Antenna  LTE Antenna for Band 30   Brand : SAE HAN ANTENNA CO.,LTD   Model Number : DH-23T-ANT   Type : Dipole Antenna   Mode Band Antenna Gain (dBi) LTE  FDD 2100 – B1 FDD 1900 PCS – B2 FDD 1800+ – B3 FDD 1800 AWS-1 – B4 FDD 850 – B5 FDD 2600 – B7 FDD 900 – B8 FDD 700a – B12 FDD 700c – B13 FDD 700b – B17 FDD 800 – B20 3.5 3.5 3.5 3.5 3.0 4.0 3.0 3.0 3.0 3.0 3.0
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 60 of 68  2017-07-19  FDD 1900+ – B25 FDD 850+ – B26 FDD 700 APT – B28 FDD 700d – B29 FDD 2300 WCS – B30 FDD AWS-3 – B66 TDD 2600 – B38 TDD 2300 – B40 TDD 2500 – B41 3.5 3.0 3.0 3.0 1.5 3.5 4.0 4.0 4.0 WCDMA  2100 – B1 1900 PCS – B2 1800 AWS-1 – B4 850 – B5 900 – B8 3.5 3.5 3.5 3.0 3.0  This transmitter must not be co-located or operating in conjunction with any other antenna or transmitter.  L'émetteur ne doit pas être colocalisé ni fonctionner conjointement avec à autre antenne ou autre émetteur.  FCC Class B digital device notice This equipment has been tested and found to comply with the limits for a Class B digital device,  pursuant  to  part  15  of  the  FCC  Rules.  These  limits  are  designed  to  provide reasonable  protection  against  harmful  interference  in  a  residential  installation.  This equipment generates, uses and can radiate radio frequency energy and, if not installed and used  in  accordance  with  the  instructions,  may  cause  harmful  interference  to  radio communications.  However,  there  is  no  guarantee  that  interference  will  not  occur  in  a particular  installation.  If  this  equipment  does  cause  harmful  interference  to  radio  or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:    Reorient or relocate the receiving antenna.   Increase the separation between the equipment and receiver.    Connect the equipment into an outlet on a circuit  different  from that to which the receiver is connected.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 61 of 68  2017-07-19    Consult the dealer or an experienced radio/TV technician for help.  Labelling Requirements for the Host device The host device shall be properly labelled to identify the modules within the host device. The certification label of the module shall be clearly visible at all times when installed in the host device, otherwise the host device must be labelled to display the FCC ID and ISED of the module, preceded by the words "Contains transmitter module", or the word "Contains", or similar wording expressing the same meaning, as follows:  L'appareil hôte doit être étiqueté comme il faut pour permettre l'identification des modules qui s'y trouvent. L'étiquette de certification du module donné doit être posée sur l'appareil hôte à un endroit bien en vue en tout temps. En l'absence d'étiquette, l'appareil hôte doit porter une étiquette donnant le FCC ID et l’ISED du module, précédé des mots « Contient un module d'émission », du mot « Contient » ou d'une formulation similaire exprimant le même sens, comme suit :  LM940 Contains FCC ID: RI7LM940 Contains IC: 5131A-LM940  CAN ICES-3 (B) / NMB-3 (B) This Class B digital apparatus complies with Canadian ICES-003.  Cet appareil numérique de classe B est conforme à la norme canadienne ICES-003.
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 62 of 68  2017-07-19  13.  SAFETY RECOMMENDATIONS   READ CAREFULLY  Be sure the use of this product is allowed in the country and in the environment required. The use of this product may be dangerous and has to be avoided in the following areas:   Where  it  can  interfere  with  other  electronic  devices  in  environments  such  as hospitals, airports, aircrafts, etc.   Where there is risk of explosion such as gasoline stations, oil refineries, etc. It is the responsibility  of  the  user  to  enforce  the  country  regulation  and  the  specific environment regulation. Do  not  disassemble  the  product;  any  mark  of  tampering  will  compromise  the  warranty validity. We recommend following the instructions of the hardware user guides for correct wiring of the product. The product has to be supplied with a stabilized voltage source and the wiring has to be conformed to the security and fire prevention regulations. The product has  to  be  handled  with  care,  avoiding  any  contact  with  the  pins  because  electrostatic discharges may damage the product itself. Same cautions have to be taken for the SIM, checking carefully the  instruction  for  its  use. Do  not  insert  or  remove  the  SIM when  the product is in power saving mode. The system integrator is responsible for the functioning of the final product; therefore, care has  to  be  taken  to  the  external  components  of  the  module,  as  well  as  any  project  or installation issue, because the risk of disturbing the GSM network or external devices or having  impact  on  the  security.  Should there  be  any  doubt,  please  refer  to  the technical documentation and the regulations in force. Every module has to be equipped with a proper antenna with specific characteristics. The antenna has to be installed with care in order to avoid  any  interference  with  other  electronic  devices  and  has  to  guarantee  a  minimum distance from the body (20 cm). In case this requirement cannot be satisfied, the system integrator has to assess the final product against the SAR regulation. The  European  Community  provides  some  Directives  for  the  electronic  equipment introduced  on  the  market.  All  of  the  relevant  information  is  available  on  the  European Community website: http://europa.eu.int/comm/enterprise/rtte/dir99-5.htm The text of the Directive 99/05 regarding telecommunication equipment is available, while the applicable Directives (Low Voltage and EMC) are available at: http://europa.eu.int/comm/enterprise/rtte/dir99-5.htm
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 63 of 68  2017-07-19  14.  REFERENCE TABLE OF RF BANDS CHARACTERISTICS RF Bands Characteristics Mode  Freq. Tx (MHz) Freq. Rx (MHz) Channels  Tx-Rx Offset WCDMA 2100 – B1 1920 ~ 1980  2110 ~ 2170  Tx: 9612 ~ 9888 Rx: 10562 ~ 10838 190 MHz WCDMA 1900 – B2 1850 ~ 1910  1930 ~ 1990  Tx: 9262 ~ 9538 Rx: 9662 ~ 9938 80 MHz WCDMA AWS – B4 1710 ~ 1755  2110 ~ 2155  Tx: 1537 ~ 1738 Rx: 1312 ~ 1513 400 MHz WCDMA 850 – B5  824 ~ 849  869 ~ 894  Tx: 4132 ~ 4233 Rx: 4357 ~ 4458 45 MHz WCDMA 900 – B8  880 ~ 915  925 ~ 960  Tx: 2712 ~ 2863 Rx: 2937 ~ 3088 45 MHz LTE 2100 – B1  1920 ~ 1980  2110 ~ 2170  Tx: 18000 ~ 18599 Rx: 0 ~ 599  190 MHz LTE 1900 – B2  1850 ~ 1910  1930 ~ 1990  Tx: 18600 ~ 19199 Rx: 600 ~ 1199 80 MHz LTE 1800+ – B3  1710 ~ 1785  1805 ~ 1880  Tx: 19200 ~ 19949 Rx: 1200 ~ 1949 95 MHz LTE AWS-1 – B4  1710 ~ 1755  2110 ~ 2155  Tx: 19950 ~ 20399 Rx: 1950 ~ 2399 400 MHz LTE 850 – B5  824 ~ 849  869 ~ 894  Tx: 20400 ~ 20649 Rx: 2400 ~ 2649 45 MHz LTE 2600 – B7  2500 ~ 2570  2620 ~ 2690  Tx: 20750 ~ 21449 Rx: 2750 ~ 3449 120 MHz LTE 900 – B8  880 ~ 915  925 ~ 960  Tx: 21450 ~ 21799 Rx: 3450 ~ 3799 45 MHz LTE 700a – B12  699 ~ 716  729 ~ 746  Tx : 23010 ~ 23179Rx : 5010 ~ 5179 30 MHz LTE 700c – B13  777 ~ 787  746 ~ 756  Tx : 27210 ~ 27659Rx : 9210 ~ 9659 -31 MHz
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 64 of 68  2017-07-19  Mode  Freq. Tx (MHz) Freq. Rx (MHz) Channels  Tx-Rx Offset LTE 700b – B17  704 ~ 716  734 ~ 746  Tx: 23730 ~ 23849 Rx: 5730 ~ 5849 30 MHz LTE 800 – B20  832 ~ 862  791 ~ 821  Tx: 24150 ~ 24449 Rx: 6150 ~ 6449 -41 MHz LTE 1900+ – B25  1850 ~ 1915  1930 ~ 1995  Tx: 8040 ~ 8689 Rx: 26040 ~ 26689 80 MHz LTE 850+ – B26  814 ~ 849  859 ~ 894  Tx: 8690 ~ 9039 Rx: 26690 ~ 27039 45 MHz LTE 700 APT – B28 703 ~ 748  758 ~ 803  Tx: 9210 ~ 9659 Rx: 27210 ~ 27659 55 MHz LTE 700 d – B29  Downlink only 717 ~ 728  Rx: 9660 ~ 9769  – LTE 2300 WCS – B30 2305 ~ 2315  2350 ~ 2360  Tx: 9770 ~ 9869 Rx: 27660 ~ 27759 45 MHz LTE AWS-3 – B66  1710 ~ 1780  2110 ~ 2200  Tx: 66436 ~ 67335 Rx: 131972 ~ 132671 400 MHz LTE TDD 2600 – B38 2570 ~ 2620  2570 ~ 2620  Tx: 37750 ~ 38250 Rx: 37750 ~ 38250 0 MHz LTE TDD 2300 – B40 2300 ~ 2400  2300 ~ 2400  Tx: 38650 ~ 39650 Rx: 38650 ~ 39650 0 MHz LTE TDD 2500 – B41 2496 ~ 2690  2496 ~ 2690  Tx: 39650 ~ 41589 Rx: 39650 ~ 41589 0 MHz
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 65 of 68  2017-07-19  15.  ACRONYMS  TTSC  Telit Technical Support Centre USB  Universal Serial Bus HS  High Speed DTE  Data Terminal Equipment UMTS  Universal Mobile Telecommunication System WCDMA  Wideband Code Division Multiple Access HSDPA  High Speed Downlink Packet Access HSUPA  High Speed Uplink Packet Access UART  Universal Asynchronous Receiver Transmitter HSIC  High Speed Inter Chip SIM  Subscriber Identification Module SPI  Serial Peripheral Interface ADC  Analog – Digital Converter DAC  Digital – Analog Converter I/O  Input Output GPIO  General Purpose Input Output CMOS  Complementary Metal – Oxide Semiconductor MOSI  Master Output – Slave Input MISO  Master Input – Slave Output CLK  Clock MRDY  Master Ready
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 66 of 68  2017-07-19   SRDY  Slave Ready CS  Chip Select RTC  Real Time Clock PCB  Printed Circuit Board ESR  Equivalent Series Resistance VSWR  Voltage Standing Wave Radio VNA  Vector Network Analyzer FDD  Frequency division duplex I2C  Inter-integrated circuit LTE  Long term evolution SOC  System-on-Chip
LM940 HW Design Guide   1VV0301352 Rev. 2   Page 67 of 68  2017-07-19  16.  DOCUMENT HISTORY  Revision  Date  Changes 0  2017-01-17  First Draft  1  2017-06-23  Changed document form  2  2017-07-19  Updated 7. RF section Updated 12.5 RF exposure
   [01.2017] Mod.0818 2017-01 Rev.0

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