Telit Wireless Solutions LM940 1.0 Guide

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LM940
Translation Board HW Design Guide
1VV0301384 Rev. 1 –2021-06-16
Telit Technical Documentation

LM940 TLB Hardware Design Guide
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Not Subject to NDA
APPLICABILITY TABLE
PRODUCTS
LM940, 1.0
LM940, 2.0

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CONTENTS
APPLICABILITY TABLE 2
CONTENTS 3
1. INTRODUCTION 5
Scope 5
Audience 5
Contact Information, Support 5
Symbol Conventions 6
Related Documents 6
2. GENERAL PRODUCT DESCRIPTION 7
Overview 7
TLB View 8
Low Power Mode (LPM) 10
Antenna Ports 11
Evaluation Board Connections 13
3. COMPONENT ASSEMBLY DIAGRAM 15
Searchable Layout 15
4. SCHEMATICS 19
5. PRODUCT AND SAFETY INFORMATION 22
Copyrights and Other Notices 22
5.1.1. Copyrights 22
5.1.2. Computer Software Copyrights 22
Usage and Disclosure Restrictions 23
5.2.1. License Agreements 23
5.2.2. Copyrighted Materials 23
5.2.3. High Risk Materials 23
5.2.4. Trademarks 23
5.2.5. Third Party Rights 24
5.2.6. Waiwer of Liability 24
Safety Recommendations 24

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6. GLOSSARY 26
7. DOCUMENT HISTORY 27

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1. INTRODUCTION
Scope
This document describes the LM940 TLB which is part of complete LM940 Development Kit
(Dev-Kit).
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 of
documentation errors contact Telit Technical Support at:
• TS[email protected]
• TS[email protected]
• TS[email protected]
• TS[email protected]
• TS[email protected]
Alternatively, use:
https://www.telit.com/contact-us/
For detailed information about where you can buy the Telit modules or for
recommendations on accessories and components visit:
https://www.telit.com
Our aim is to make this guide as helpful as possible. Keep us informed of your comments
and suggestions for improvements.
Telit appreciates the user feedback on our information.

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Symbol Conventions
Danger: This information MUST be followed or catastrophic equipment
failure or personal injury may occur.
Warning: Alerts the user on important steps about the module
integration.
Note/Tip: Provides advice and suggestions that may be useful when
integrating the module.
Electro-static Discharge: Notifies the user to take proper grounding
precautions before handling the product.
Table 1: Symbol Conventions
All dates are in ISO 8601 format, that is YYYY-MM-DD.
Related Documents
•LM940 Hardware User Guide, 1VV301352
•Generic Evaluation Board Hardware User Guide, 1VV0301249
•LM940 SW User Guide, 1VV0301343

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2. GENERAL PRODUCT DESCRIPTION
Overview
The Translation Board (TLB) is custom-designed to interface the Telit LM940 module with
the Telit Generic Evaluation Board (EVB), thus forming the complete LM940 Development
Kit.
The TLB maps Telit the signals and functions of the Telit module into generic EVB signals
and functions.
The LM940 TLB design includes the following items:
•LM940 socket
•RF SMA connectors
•Board to Board connectors for interfacing to EVB main board
•Module specific circuitry which is not part of the generic EVB circuitry
Power supply and control interface for the module is provided by the EVB through the
board-to-board (B2B) connectors.
To monitor the temperature, a thermistor is placed close to the module on the upper
ground plane: this in order to properly measure the temperature of the rear of the module.
Under the module, the bottom plane PCB solder-mask is cutout to optimally mount/attach
a heatsink aiming to cool the module.
The board is designed to accommodate modules according to the LM940 MINI PCIE (50.95
x 30.00 x 2.70mm, +/- 0.15 mm tolerance and 52 pins) updated pin mapping.
PCB reference numbers:
Board
PCB Code
EVB
CS1742E
TLB
CS1824A, CS1914B
Module
LM940 1.0, LM940 2.0 (CS1822x)
Table 2: PCB reference numbers

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TLB View
The below pictures show the TLB top and bottom view.
LM940 1.0 TLB Top View
Figure 1: LM940 1.0 TLB Top View
LM940 1.0 TLB Bottom View
Figure 2: LM940 1.0 TLB Bottom View

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LM940 2.0 TLB Top View
Figure 3: LM940 2.0 TLB Top View
LM940 2.0 TLB Bottom View
Figure 4: LM940 2.0 TLB Bottom View

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Low Power Mode (LPM)
Figure 5: Low Power Mode
This section contains how to switch to LPM mode by means of a header jumper.
Jumper Header
Description
2 –3: Low
LPM mode
W_DISABLE_N
The W_DISABLE_N signal is provided to trigger
the LM940 to switch to Low Power Mode (also
known as “Airplane Mode”).
Table 3: how to switch to LPM mode by means of a header jumper

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Antenna Ports
LM940 1.0 TLB
Figure 6: LM940 1.0 TLB Antenna Ports

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LM940 2.0 TLB
Figure 7: LM940 2.0 TLB Antenna Ports
Note: For more detailed information regarding Antenna ports, please
refer to 1VV0301352 LM940 HW Design Guide, Chapter “Antenna
requirements”.

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Evaluation Board Connections
Figure 8: Telit Evaluation Board
Note: For more detailed information regarding power supply source
selection, please refer to 1VV0301249 Telit Evaluation Board (EVB) HW
User Guide, Chapter “Supply Source Selection”.
Figure 9: 12V AC Adaptor

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Figure 10: Interface of Telit Evaluation Board
Interface
Desciption
SIM Card
Both SIM 1 and SIM2 sockets on the EVB can be used
Power ON
To Power-ON the Telit module, connect an AC adaptor
Power OFF
To Power-OFF the Telit module, unplug an adaptor
Modem Reset
To reset the Telit module, press the reset button for
more than 2 seconds
AT Commands / DATA port
Connect the USB 2.0/3.0 cable to a Windows or Linux PC
only after installing the appropriate drivers. Refer to the
LM940 SW User Guide for details
Table 4: Interface and Description of Telit EVB

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3. COMPONENT ASSEMBLY DIAGRAM
Searchable Layout
LM940 1.0 Component Diagram TOP View
Figure 11: LM940 1.0 Component Diagram TOP View

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LM940 1.0 Component Diagram BOTTOM View
Figure 12: LM940 1.0 Component Diagram BOTTOM View

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LM940 2.0 Component Diagram TOP View
Figure 13: LM940 2.0 Component Diagram TOP View

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LM940 2.0 Component Diagram BOTTOM View
Figure 14: LM940 2.0 Component Diagram BOTTOM View

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4. SCHEMATICS
Searchable PDF
LM940 1.0 TLB
Figure 15: LM940 1.0 TLB Schematic (1/2)
Figure 16: LM940 1.0 TLB Schematic (2/2)

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LM940 2.0 TLB
Figure 17: LM940 2.0 TLB Schematic (1/2)
Figure 18: LM940 2.0 TLB Schematic (1/2)