Telit Communications S p A LE920NA1 User Manual

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LE920 Hardware User Guide

1vv0301026 Rev.9 - 2016-03-29

PRODUCT

LE920-EUG (cs1550f-B)

LE920-NAG (cs1550f-A)

LE920-EU (cs1647c)

LE920-NA (cs1701)

LE920-CN (cs1648D)

LE920-NA AUTO S (cs1717)

LE920 Hardware User Guide

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APPLICABILITY TABLE

APPLICABILITY TABLE 1

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SPECIFICATIONS 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 entirely 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.

LE920 Hardware User Guide

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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.

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

High Risk Materials

Components, units, or third-party products used in the product described herein are NOT faulttolerant 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.

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.

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Contents

1. Introduction ................................................. 9

1.1. Scope ..................................................... 9

1.2. Audience .................................................. 9

1.3. Contact Information, Support .............................. 9

1.4. Document Organization .................................... 10

1.5. Text Conventions ......................................... 11

1.6. Related Documents ........................................ 11

2. General Product Description ................................. 12

2.1. Overview ................................................. 12

2.2. LE920 Mechanical Dimensions .............................. 13

2.3. Weight ................................................... 13

2.4. Environmental requirements ............................... 14

2.4.1. Temperature range .......................................... 14

2.4.2. RoHS compliance ............................................ 14

2.5. Operating Frequency ...................................... 15

2.5.1. LE920-EUG(cs1550f-B), LE920-EU (cs1647c) ................... 15

2.5.2. LE920-NAG (cs1550f-A) ...................................... 15

2.5.3. LE920-NA (cs1701), LE920-NA AUTO S (cs1717) ................ 16

2.5.4. LE920-CN (cs1648D) ......................................... 17

2.6. Sensitivity .............................................. 18

2.7. Conformity assessment issues .............................. 18

2.7.1. FCC/IC Regulatory notices .................................. 18

2.7.1.1. Modification statement .................................. 18

2.7.1.2. Interference statement .................................. 18

2.7.1.3. RF exposure ............................................. 18

2.7.1.4. FCC Class B digital device notice ....................... 19

2.7.1.5. Labelling Requirements for the Host device .............. 19

3. LE920 Module Connections .................................... 21

3.1. PIN-OUT .................................................. 21

3.1.1. LGA Pads Layout ............................................ 28

4. Hardware Commands ........................................... 29

4.1. Turning ON the LE920 ..................................... 29

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4.2. Initialization and Activation state ...................... 29

4.3. Turning OFF the LE920 .................................... 30

4.3.1. Shutdown by Software Command ............................... 31

4.3.2. Hardware Shutdown .......................................... 32

4.3.3. Hardware Unconditional Restart (RESET) ..................... 33

4.3.4. Hardware Unconditional Shutdown ............................ 34

4.4. Summary of Turning ON and OFF the module ................. 35

5. Power Supply ................................................ 36

5.1. Power Supply Requirements ................................ 36

5.2. General Design Rules ..................................... 38

5.2.1. Electrical Design Guidelines ............................... 38

5.2.1.1. + 5V Input Source Power Supply Design Guidelines ........ 38

5.2.1.2. + 12V Input Source Power Supply Design Guidelines ....... 39

5.2.1.3. Battery Source Power Supply Design Guidelines ........... 41

5.2.2. Thermal Design Guidelines .................................. 42

5.2.3. Power Supply PCB Layout Guidelines ......................... 43

6. Antenna(s) .................................................. 45

6.1. GSM/WCDMA/LTE Antenna Requirements ....................... 45

6.2. GSM/WCDMA/LTE Antenna – PCB line Guidelines .............. 46

6.3. GSM/WCDMA/LTE Antenna – Installation Guidelines .......... 47

6.4. Antenna Diversity Requirements ........................... 47

6.5. GPS/GNSS Antenna Requirements ............................ 48

6.5.1. Combined GPS/GNSS Antenna .................................. 49

6.5.2. Linear and Patch GPS/GNSS Antenna .......................... 49

6.5.3. Front End Design Considerations ............................ 49

6.5.4. GPS/GNSS Antenna - PCB Line Guidelines ..................... 50

6.5.5. GPS/GNSS Antenna – Installation Guidelines ................. 50

7. Logic Level Specifications .................................. 51

8. USB Port .................................................... 52

9. Serial Ports ................................................ 53

9.1. Modem Serial Port 1 ...................................... 54

9.2. Modem Serial Port 2 ...................................... 55

9.3. RS232 Level Translation .................................. 55

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10. Peripheral Ports ............................................ 57

10.1. SPI – Serial Peripheral Interface ...................... 57

10.2. I2C - Inter-integrated circuit ......................... 58

10.3. SDIO – Secure Digital I/O .............................. 58

10.4. Wi-Fi (SDIO) control Interface ......................... 60

11. Audio Section Overview ...................................... 61

11.1. Analog Audio ........................................... 61

11.2. Digital Audio .......................................... 61

12. General Purpose I/O ......................................... 63

12.1. Logic Level Specifications ............................. 64

12.2. Using a GPIO Pad as Input .............................. 64

12.3. Using a GPIO Pad as Output ............................. 65

12.4. Using the Temperature Monitor Function ................. 65

12.4.1. Short Description ........................................ 65

12.5. Indication of Network Service Availability ............. 66

12.6. RTC Bypass ............................................. 67

12.7. VAUX Power Output ...................................... 67

13. ADC section ................................................. 68

13.1. ADC Converter .......................................... 68

13.1.1. Description .............................................. 68

13.1.2. Using ADC Converter ...................................... 68

14. Mounting the module on your board ........................... 69

14.1. General ................................................ 69

14.2. Finishing & Dimensions ................................. 69

14.3. Recommended foot print for the application ............. 70

14.4. Stencil ................................................ 71

14.5. PCB Pad Design ......................................... 71

14.6. Recommendations for PCB Pad Dimensions (mm) ............ 72

14.7. Solder Paste ........................................... 73

14.7.1. Solder Reflow ............................................ 73

15. Application guide ........................................... 75

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15.1. Debug of the LE920 in production ....................... 75

15.2. Bypass capacitor on Power supplies ..................... 76

15.3. SIM interface .......................................... 77

15.3.1. SIM schematic example .................................... 77

15.3.2. eSIM interface guidelines ................................ 78

15.4. EMC recommendations .................................... 80

15.5. Download and Debug Port ................................ 81

16. Packing system .............................................. 82

16.1. Tray Drawing ........................................... 84

16.2. Moisture Sensitivity ................................... 85

17. Safety Recommendations ...................................... 86

18. Document History ............................................ 87

- Adding section 2.7 Conformity assessment issues ............................. 88

1. Introduction

1.1. Scope

The aim of this document is to present possible and recommended hardware solutions useful for developing a product with the Telit LE920 module. All the features and solutions detailed are applicable to all LE920, where “LE920” refers to the modules listed in the applicability table.

If a specific feature is applicable to a specific product, it will be clearly highlighted.

NOTICE:

The description text “LE920” refers to all modules listed in the APPLICABILITY TABLE 1.

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1.2. Audience

This document is intended for Telit customers, especially system integrators, about to implement their applications using our LE920 module.

1.3. Contact Information, Support

For general contact, technical support, to report documentation errors and to order manuals, contact Telit’s Technical Support Center (TTSC) at:

TS-EMEA@telit.com TS-NORTHAMERICA@telit.com TS-LATINAMERICA@telit.com TS-APAC@telit.com

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.

1.4. Document Organization

This document contains the following chapters:

Chapter 1: “Introduction” provides a scope for this document, target audience, contact and

support information, and text conventions.

Chapter 2: “General Product Description” gives an overview of the features of the product.

Chapter 3: “LE920 Module Connections” deals with the pin out configuration and layout.

Chapter 4: “Hardware Commands” instructs how to control the module via hardware

Chapter 5: “Power Supply” deals with supply and consumption.

Chapter 6: “Antenna” The antenna connection and board layout design are the most important

parts in the full product design

Chapter 7: “Logic Level specifications” Specific values adopted in the implementation of

logic levels for this module.

Chapter 8: “USB Port”

Chapter 9: “Serial Ports”

Chapter 10: “Peripheral Ports”

Chapter 11: “Audio Section Overview”

Chapter 12: “General Purpose I/O” How the general purpose I/O pads can be configured.

Chapter 13 “DAC and ADC Section” Deals with these two kind of analog converters.

Chapter 14: “Mounting the module on your board”

Chapter 15: “Application Guides”

Chapter 16: “Packing System”

Chapter 17: “Safety Recommendations”

Chapter 18: “Document History”

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1.5. 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.

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1.6. Related Documents

 LE920-EUG/NAG Product Description, 80407ST10118A

 LE920-EUG/NAG AT command reference guide, 80407ST10116A

 Telit EVK2 User Guide, 1vv0300704

 Telit xE920 Audio Settings Application Note, 80404NT10095A

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2. General Product Description

2.1. Overview

The aim of this document is to present possible and recommended hardware solutions useful for developing a product with the Telit LE920 module.

In this document all the basic functions of a wireless module will be taken into account; for each one of them a valid hardware solution will be suggested and usually incorrect solutions and common errors to be avoided will be highlighted. Obviously this document cannot embrace every hardware solution or every product that may be designed. Obviously avoiding invalid solutions must be considered as mandatory. Whereas 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 LE920 module.

NOTICE:

The integration of the GSM/GPRS/EGPRS/WCDMA/HSPA+/LTE LE920 cellular module within user application must be done according to the design rules described in this manual.

The information presented in this document is believed to be accurate and reliable. However, no responsibility is assumed by Telit Communication S.p.A. for its use, such as any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent rights of Telit Communication S.p.A. other than for circuitry embodied in Telit products. This document is subject to change without notice.

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2.2. LE920 Mechanical Dimensions

The Telit LE920 module overall dimensions are:

• Length: 34 mm , +/- 0.15 mm Tolerance

• Width: 40 mm , +/- 0.15 mm Tolerance

• Thickness: 2.9 mm , +/- 0.13 mm Tolerance

2.3. Weight

The module weight of LE920 is about 9.0 gram.

LE920 Hardware User Guide

Operating Temperature Range

–40°C ~ +85°C

Storage and non-operating Temperature Range

–40°C ~ +85°C

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2.4. Environmental requirements

2.4.1. Temperature range

2.4.2. RoHS compliance

LE920 Hardware User Guide

As a part of Telit corporate policy of environmental protection, the LE920 complies with the RoHS (Restriction of Hazardous Substances) directive of the European Union (EU directive 2011/65/EU).

Mode

Freq. TX (MHz)

Freq. RX (MHz)

Channels

TX - RX offset

GSM850

824 ~ 849

869 ~ 894

128 ~ 251

45 MHz

EGSM900 890 ~ 915

935 ~ 960

0 ~ 124

45 MHz

880 ~ 890

925 ~ 935

975 ~ 1023

45 MHz

DCS1800

1710 ~ 1785

1805 ~ 1880

512 ~ 885

95MHz

PCS1900

1850 ~ 1910

1930 ~ 1990

512 ~ 810

80MHz

WCDMA2100 – B1

1920 ~ 1980

2110 ~ 2170

Tx: 9612 ~ 9888 Rx: 10562 ~ 10838

190MHz

WCDMA1800 – B3

1710 ~ 1785

1805 ~ 1880

Tx: 937 ~ 1288 Rx: 1162 ~ 1513

95MHz

WCDMA900 – B8

880 ~ 915

925 ~ 960

Tx: 2712 ~ 2863 Rx: 2937 ~ 3088

45MHz

LTE2100 – B1

1920 ~ 1980

2110 ~ 2170

Tx: 18000 ~ 18599 Rx: 0 ~ 599

190MHz

LTE1800 – B3

1710 ~ 1785

1805 ~ 1880

Tx: 19200 ~ 19949 Rx: 1200 ~ 1949

95MHz LTE2600 – B7

2500 ~ 2570

2620 ~ 2690

Tx: 20750 ~ 21449 Rx: 2750 ~ 3449

120MHz

LTE900 – B8

880 ~ 915

925 ~ 960

Tx: 21450 ~ 21799 Rx: 3450 ~ 3799

45MHz

LTE800 – B20

832 ~ 862

791 ~ 821

Tx: 24150 ~ 24449 Rx: 6150 ~ 6449

-41MHz Mode

Freq. TX (MHz)

Freq. RX (MHz)

Channels

TX - RX offset

GSM850

824 ~ 849

869 ~ 894

128 ~ 251

45 MHz

EGSM900 890 ~ 915

935 ~ 960

0 ~ 124

45 MHz

880 ~ 890

925 ~ 935

975 ~ 1023

45 MHz

DCS1800

1710 ~ 1785

1805 ~ 1880

512 ~ 885

95MHz

PCS1900

1850 ~ 1910

1930 ~ 1990

512 ~ 810

80MHz

WCDMA2100 – B1

1920 ~ 1980

2110 ~ 2170

Tx: 9612 ~ 9888 Rx: 10562 ~ 10838

190MHz

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2.5. Operating Frequency

The operating frequencies in GSM850, EGSM900, DCS1800, PCS1900, WCDMA & LTE modes are conformed to the 3GPP specifications.

2.5.1. LE920-EUG(cs1550f-B), LE920-EU (cs1647c)

2.5.2. LE920-NAG (cs1550f-A)

LE920 Hardware User Guide

WCDMA1900 – B2

1850 ~ 1910

1930 ~ 1990

Tx: 9262 ~ 9538 Rx: 9662 ~ 9938

80MHz

WCDMA1700 – B4

1710 ~ 1755

2110 ~ 2155

Tx: 1312 ~ 1513 Rx: 1537 ~ 1738

400 MHz

WCDMA850 – B5

824 ~ 849

869 ~ 894

Tx: 4132 ~ 4233 Rx: 4357 ~ 4458

45MHz

WCDMA800 – B6

830 ~ 840

875 ~ 885

Tx: 4162 ~ 4188 Rx: 4387 ~ 4413

45MHz LTE2100 – B1

1920 ~ 1980

2110 ~ 2170

Tx: 18000 ~ 18599 Rx: 0 ~ 599

190MHz

LTE1900 – B2

1850 ~ 1910

1930 ~ 1990

Tx: 18600 ~ 19199 Rx: 600 ~ 1199

80MHz LTE1700 – B4

1710~ 1755

2110 ~ 2155

Tx: 19950 ~ 20399 Rx: 1950 ~ 2399

400MHz

LTE850 – B5

824 ~ 849

869 ~ 894

Tx: 20400 ~ 20649 Rx: 2400 ~ 2649

45MHz

LTE700 – B17

704 ~ 716

734 ~ 746

Tx: 23730 ~ 23849 Rx: 5730 ~ 5849

30MHz

WCDMA1900 – B2

1850 ~ 1910

1930 ~ 1990

Tx: 9262 ~ 9538 Rx: 9662 ~ 9938

80MHz

WCDMA1700 – B4

1710 ~ 1755

2110 ~ 2155

Tx: 1312 ~ 1513 Rx: 1537 ~ 1738

400 MHz

WCDMA850 – B5

824 ~ 849

869 ~ 894

Tx: 4132 ~ 4233 Rx: 4357 ~ 4458

45MHz LTE1900 – B2

1850 ~ 1910

1930 ~ 1990

Tx: 18600 ~ 19199 Rx: 600 ~ 1199

80MHz

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2.5.3. LE920-NA (cs1701), LE920-NA AUTO S (cs1717)

Mode Freq. TX (MHz) Freq. RX (MHz) Channels TX - RX offset

LE920 Hardware User Guide

LTE1700 – B4

1710~ 1755

2110 ~ 2155

Tx: 19950 ~ 20399 Rx: 1950 ~ 2399

400MHz

LTE850 – B5

824 ~ 849

869 ~ 894

Tx: 20400 ~ 20649 Rx: 2400 ~ 2649

45MHz

LTE2600 – B7

2500 ~ 2570

2620 ~ 2690

Tx: 20750 ~ 21449 Rx: 2750 ~ 3449

120MHz

30MHz Mode

Freq. TX (MHz)

Freq. RX (MHz)

Channels

TX - RX offset

EGSM900 890 ~ 915

935 ~ 960

0 ~ 124

45 MHz

880 ~ 890

925 ~ 935

975 ~ 1023

45 MHz

DCS1800

1710 ~ 1785

1805 ~ 1880

512 ~ 885

95MHz

WCDMA2100 – B1

1920 ~ 1980

2110 ~ 2170

Tx: 9612 ~ 9888 Rx: 10562 ~ 10838

190MHz

WCDMA1800 – B3

1710 ~ 1785

1805 ~ 1880

Tx: 937 ~ 1288 Rx: 1162 ~ 1513

95MHz WCDMA900 – B8

880 ~ 915

925 ~ 960

Tx: 2712 ~ 2863 Rx: 2937 ~ 3088

45MHz

LTE2100 – B1

1920 ~ 1980

2110 ~ 2170

Tx: 18000 ~ 18599 Rx: 0 ~ 599

190MHz

LTE1800 – B3

1710 ~ 1785

1805 ~ 1880

Tx: 19200 ~ 19949 Rx: 1200 ~ 1949

95MHz LTE900 – B8

880 ~ 915

925 ~ 960

Tx: 21450 ~ 21799 Rx: 3450 ~ 3799

45MHz

LTE TDD 2600 – B38

2570 ~ 2620

Tx: 37750 ~ 38250 Rx: 37750 ~ 38250

0MHz LTE TDD 1900 – B39

1880 ~ 1920

Tx: 38250 ~ 38650 Rx: 38250 ~ 38650

0MHz LTE TDD 2300 – B40

2300 ~ 2400

Tx: 38650 ~ 39650 Rx: 38650 ~ 39650

0MHz LTE TDD 2500 – B41

2496 ~ 2690

Tx: 39650 ~ 41590 Rx: 39650 ~ 41590

0MHz TDSCDMA2000 – B34

2010 ~ 2025

Tx: 10054 ~ 10121 Rx: 10054 ~ 10121

0MHz TDSCDMA1900 – B39

1880 ~ 1920

Tx: 9404 ~ 9596 Rx: 9404 ~ 9596

0MHz

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LTE700 – B17 704 ~ 716 734 ~ 746

2.5.4. LE920-CN (cs1648D)

Tx: 23730 ~ 23849 Rx: 5730 ~ 5849

Frequency band

Antenna gain

700 MHz

5,66 dBi

850 MHz

6,13 dBi

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2.6. Sensitivity

LE920 maximum sensitivity levels are as follow:

 -113 dBm @ 2G

 -112 dBm @ 3G

 -111 dBm @ TD-SCDMA (BW=1.6MHz)

 -102 dBm @ 4G FDD (BW=5MHz)

 -101 dBm @ 4G TDD (BW=5MHz)

2.7. Conformity assessment issues

2.7.1. FCC/IC Regulatory notices

2.7.1.1. 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.

2.7.1.2. 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 brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le fonctionnement.

2.7.1.3. RF exposure

This equipment complies with FCC and IC 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:

1700 MHz

5,00 dBi

1900 MHz

8,01 dBi

2600 MHz

8,01 dBi

Bande de fréquence

Gain de l'antenne

700 MHz

5,66 dBi

850 MHz

6,13 dBi

1700 MHz

5,00 dBi

1900 MHz

8,01 dBi

2600 MHz

8,01 dBi

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This transmitter must not be co-located or operating in conjunction with any other antenna or transmitter.

Cet appareil est conforme aux limites d'exposition aux rayonnements de la IC 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:

L'émetteur ne doit pas être colocalisé ni fonctionner conjointement avec à autre antenne ou autre émetteur.

2.7.1.4. 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.

- Consult the dealer or an experienced radio/TV technician for help.

2.7.1.5. 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 IC of the module, preceded by the words "Contains transmitter module", or the word "Contains", or similar wording expressing the same meaning, as follows:

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Contains FCC ID: RI7LE920NA1 Contains IC: 5131A-LE920NA1

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 le IC du module, précédé des mots « Contient un module d'émission », du mot « Contient » ou d'une formulation similaire exprimant le même sens, comme suit:

Contains FCC ID: RI7LE920NA1 Contains IC: 5131A-LE920NA1

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.

PAD

Signal

I/O

Function

Type

COMMENT

USB HS 2.0 Communication Port

D19

USB_D+

I/O

USB differential Data(+)

F19

USB_D-

I/O

USB differential Data(-)

A18

USB_VBUS

Power sense for the internal USB transceiver

Power

2.2V – 5.25V @ max 5mA

Asynchronous UART – Prog. / data +HW Flow Control

AH19

C103/TXD

Serial data input (TXD) from DTE

1.8V

AF19

C104/RXD

Serial data output to DTE

1.8V

AC18

C108/DTR

Input for Data terminal ready signal (DTR) from DTE

1.8V

AA18

C105/RTS

Input for Request to send signal (RTS) from DTE

1.8V

AK19

C106/CTS

Output for Clear to send signal (CTS) to DTE

1.8V

AE18

C109/DCD

Output for Data carrier detect signal (DCD) to DTE

1.8V

AG18

C107/DSR

Output for Data set ready signal (DSR) to DTE

1.8V

AJ18

C125/RING

Output for Ring indicator signal (RI) to DTE

1.8V

Asynchronous Auxiliary UART

AB19

TXD_AUX

Auxiliary UART (TX Data to DTE)

1.8V

AD19

RXD_AUX

Auxiliary UART (RX Data from DTE)

1.8V

SPI – Serial Peripheral Interface

P19

SPI_CLK

SPI Clock output

1.8V

M19

SPI_MISO

SPI data Master Input Slave output

1.8V

K19

SPI_MOSI

SPI data Master Output Slave input

1.8V

N18

SPI_CS

SPI Chip select output

1.8V

SDIO – Secure Digital I/O

AH17

SD/MMC_CMD

SD Command

1.8/2.95V

AD17

SD/MMC_CLK

SD Card Clock

1.8/2.95V

Y17

SD/MMC_DATA0

I/O

SD Serial Data 0

1.8/2.95V

AF17

SD/MMC_DATA1

I/O

SD Serial Data 1

1.8/2.95V

AB17

SD/MMC_DATA2

I/O

SD Serial Data 2

1.8/2.95V

W17

SD/MMC_DATA3

I/O

SD Serial Data 3

1.8/2.95V

U17

SD/MMC_CD

SD card detect input

1.8V

Active Low

Wi-Fi (SDIO) control Interface

AB3

WiFi_SD_CMD

Wi-Fi SD Command

1.8V

AM3

WiFi_SD_CLK

Wi-Fi SD Clock

1.8V

AD3

WiFi_SD _DATA0

I/O

Wi-Fi SD Serial Data 0

1.8V

AF3

WiFi_SD _DATA1

I/O

Wi-Fi SD Serial Data 1

1.8V

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

3. LE920 Module Connections

3.1. PIN-OUT

PAD

Signal

I/O

Function

Type

COMMENT

AH3

WiFi_SD _DATA2

I/O

Wi-Fi SD Serial Data 2

1.8V

AK3

WiFi_SD _DATA3

I/O

Wi-Fi SD Serial Data 3

1.8V

WiFi_RST_Ctr

Wi-Fi Reset output control / Power enable control

1.8V

Active Low

SIM Card Interface 1

A10

SIMCLK1

External SIM signal – Clock

1.8/2.85V

B11

SIMRST1

External SIM signal – Reset

1.8/2.85V

SIMIO1

I/O

External SIM signal - Data I/O

1.8/2.85V

SIMIN1

External SIM signal - Presence (active low)

1.8V

SIMVCC1

External SIM signal – Power supply for the SIM

1.8/2.85V

ESIM_RST

Internal eSIM signal – Reset

1.8/2.85V

Analog Audio interface

EAR1_MT+

Earphone signal output1, phase +

Audio

EAR1_MT-

Earphone signal output1, phase -

Audio

MIC1_MT+

Mic signal input1, phase +

Audio

MIC1_MT-

Mic signal input1, phase -

Audio

Digital Voice interface (DVI)

D11

DVI_WA0

Digital Voice interface (WA0 master output)

1.8V

DVI_RX

Digital Voice interface (RX)

1.8V

DVI_TX

Digital Voice interface (TX)

1.8V

C10

DVI_CLK

Digital Voice interface (CLK master output)

1.8V

Digital I/O

GPIO_01

I/O

GPIO_01

1.8V

I2C alternate

E10

GPIO_02

I/O

GPIO_02

1.8V

I2C alternate

F11

GPIO_03

I/O

GPIO_03

1.8V

I2C alternate

E12

GPIO_04

I/O

GPIO_04

1.8V

I2C alternate

F13

GPIO_05

I/O

GPIO_05

1.8V

I2C alternate

E14

GPIO_06

I/O

GPIO_06

1.8V

I2C alternate

R18

GPIO_07

I/O

GPIO_07

1.8V

I2C alternate

S19

GPIO_08

I/O

GPIO_08

1.8V

I2C alternate

U19

GPIO_09

I/O

GPIO_09

1.8V

I2C alternate

W19

GPIO_10

I/O

GPIO_10

1.8V

I2C alternate

RF Section

AD1

Antenna

I/O

GSM/EDGE/UMTS/LTE Antenna (50 Ohm)

AU9

ANT_DIV

UMTS/LTE Antenna Diversity Input (50 Ohm)

GPS Section

ANT_GPS

GPS Antenna (50 Ohm)

GPS_LNA_EN

Enable the external regulator for GPS LNA

1.8V

Miscellaneous Function

AP1

RESET#

Reset Input

Active Low

AS1

ON_OFF#

Input Command for Power ON

Active Low

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

PAD

Signal

I/O

Function

Type

COMMENT

AN12

SHDN_N

Unconditional Shut down Input

Active Low

P17

VAUX/PWRMON

Supply Output for External Accessories / Power ON Monitor

1.8V

F17

VRTC

AI/ AO

VRTC Backup Capacitor

Power

To be used to back up the RTC section

ADC_IN1

Analog/Digital Converter Input 1

Analog

ADC_IN2

Analog/Digital Converter Input 2

Analog

ADC_IN3

Analog/Digital Converter Input 3

Analog

AU3

STAT_LED

Status Indicator LED

1.8V

AN10

SW_RDY

Indicates that the boot sequence completed successfully

1.8V

Power Supply

AP17

VBATT

Main Power Supply (Digital Section)

Power

AP19

VBATT

Main Power Supply (Digital Section)

Power

AR18

VBATT

Main Power Supply (Digital Section)

Power

AS17

VBATT_PA

Main Power Supply (RF Transmit Power Section)

Power

AS19

VBATT_PA

Main Power Supply (RF Transmit Power Section)

Power

AT18

VBATT_PA

Main Power Supply (RF Transmit Power Section)

Power

AU17

VBATT_PA

Main Power Supply (RF Transmit Power Section)

Power

AU19

VBATT_PA

Main Power Supply (RF Transmit Power Section)

Power

GND

Ground

A12

GND

Ground

B13

GND

Ground

B15

GND

Ground

B17

GND

Ground

GND

Ground

GND

Ground

GND

Ground

GND

Ground

E18

GND

Ground

GND

Ground

G18

GND

Ground

H19

GND

Ground

GND

Ground

GND

Ground

GND

Ground

GND

Ground

GND

Ground

GND

Ground

T18

GND

Ground

GND

Ground

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

PAD

Signal

I/O

Function

Type

COMMENT

V18

GND

Ground

GND

Ground

GND

Ground

X18

GND

Ground

GND

Ground

Y19

GND

Ground

AA2

GND

Ground

AB1

GND

Ground

AC2

GND

Ground

AE2

GND

Ground

AF1

GND

Ground

AG2

GND

Ground

AH1

GND

Ground

AJ2

GND

Ground

AK1

GND

Ground

AK17

GND

Ground

AL18

GND

Ground

AM17

GND

Ground

AM19

GND

Ground

AN16

GND

Ground

AN18

GND

Ground

AP3

GND

Ground

AP5

GND

Ground

AP7

GND

Ground

AP9

GND

Ground

AP11

GND

Ground

AP13

GND

Ground

AP15

GND

Ground

AR2

GND

Ground

AR4

GND

Ground

AR6

GND

Ground

AR8

GND

Ground

AR10

GND

Ground

AR12

GND

Ground

AR14

GND

Ground

AR16

GND

Ground

AS5

GND

Ground

AS7

GND

Ground

AS9

GND

Ground

AS11

GND

Ground

AS13

GND

Ground

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

PAD

Signal

I/O

Function

Type

COMMENT

AS15

GND

Ground

AT4

GND

Ground

AT6

GND

Ground

AT8

GND

Ground

AT10

GND

Ground

AT12

GND

Ground

AT14

GND

Ground

AT16

GND

Ground

AU1

GND

Ground

AU5

GND

Ground

AU7

GND

Ground

AU11

GND

Ground

AU15

GND

Ground

Reserved

C12

Reserved

A14

Reserved

A16

Reserved

M17

Reserved

AN6

Reserved

C14

Reserved

D13

Reserved

C16

Reserved

D17

Reserved

E16

Reserved

C18

Reserved

D15

Reserved

F15

Reserved

H17

Reserved

J18

Reserved

K17

Reserved

L18

Reserved

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

PAD

Signal

I/O

Function

Type

COMMENT

Reserved

S17

Reserved

AL2

Reserved

AM1

Reserved

AN2

Reserved

AN4

Reserved

AN8

Reserved

AN14

Reserved

AS3

Reserved

AT2

Reserved

B19

Reserved

AU13

Reserved

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

NOTE:

When the UART signals are used as the communication port between the Host and the Modem:

- DTR pin must be connected in order to enter LE920’s power saving mode.

- RI pin must be connected in order to wake the host when a call is coming during sleep

mode of host.

- RTS must be connected to GND (on the module side) if flow control is not used

In case UART port isn’t used, all UART signals may be left disconnected

NOTE:

E8 port – eSIM Reset signal is available for LE920-NA AUTO S model only. For other models, E8 is internally disconnected.

NOTE:

Unless otherwise specified, RESERVED pins must be left unconnected (Floating).

PAD

Signal

Notes

AP17,AP19,AR18,AS17,AS19,AT18,AU17,AU19

VBATT & VBATT_PA

A6,A12,B13,B15,B17,C4,C6,D3,D7,E18,F1,G18,H19, M1,N2,P1,P3,R2,T2,T18,U1,V18,W1,X2,X18,Y1,Y19, AA2,AB1,AC2,AE2,AF1,AG2,AH1,AJ2,AK1,AK17, AL18,AM17,AM19,AN16,AN18,AP3,AP5,AP7,AP9, AP11,AP13,AP15,AR2,AR4AR6,AR8,AR10,AR12, AR14,AR16,AS5,AS7,AS9,AS11,AS13,AS15,AT4, AT6,AT8,AT10,AT12,AT14,AT16,AU1,AU5,AU7, AU11,AU15

GND

AS1

ON/OFF*

AN12

SHDN_N

D19

USB_D+

If not used should be connected to a Test Point or an USB connector

F19

USB_D-

If not used should be connected to a Test Point or an USB connector

A18

USB_VBUS

If not used should be connected to a Test Point or an USB connector

AH19

C103/TXD

If not used should be connected to a Test Point

AF19

C104/RXD

If not used should be connected to a Test Point

AA18

C105/RTS

If the flow control is not used it should be connected to GND

AK19

C106/CTS

If not used should be connected to a Test Point

AB19

TXD_AUX

If not used should be connected to a Test Point

AD19

RXD_AUX

If not used should be connected to a Test Point

AD1

Antenna

AU9

ANT_DIV

ANT_GPS

G2, J2, L2, F3, H3, K3, E4, AN14

Reserved

If not used should be connected to a Test Point

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

The table below specifies the LE920A4 signals that must be connected even if not used by end application:

3.1.1. LGA Pads Layout

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

4. Hardware Commands

4.1. Turning ON the LE920

To turn on LE920, the pad ON# must be tied low for at least 1 second and then released.

The maximum current that can be drained from the ON# pad is 0.1 mA.

A simple circuit to power on the module is illustrated below:

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

4.2. Initialization and Activation state

Upon turning on LE920 module, The LE920 is not activated yet because the boot sequence of LE920 is still going on internally. It takes about 10 seconds to complete the initializing the module internally.

For this reason, it would be useless to try to access LE920 during the Initialization state, as shown below. To reach full stability, The LE920 needs at least 15 seconds after the PWRMON goes High to become operational by reaching the activation state.

During the Initialization state, any kind of AT-command is not available. DTE must wait for the Activation state before communicating with LE920.

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

NOTE:

To check if the LE920 has powered on, the hardware line PWRMON must be monitored. When PWRMON goes high, the module has powered on.

NOTE:

Do not use any pull up resistor on the ON# line, it is internally pulled up. Using pull up resistor may cause latch-up problems on the LE920 power regulator and improper powering on/off of the module. The line ON# must be connected only in an open collector configuration.

NOTE:

In this document all the lines are inverted. Active low signals are labeled with a name that ends with "#" or with a bar over the name.

NOTE:

In order 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.

4.3. Turning OFF the LE920

Turning off the device can be done in four different ways:

 by Software command AT#SHDN

 by Hardware Shutdown using pad ON/OFF#

 by Hardware Unconditional Reset using the RESET#

 by Hardware Unconditional Shutdown using the SHDN#

When the device is shut down by software command or by hardware shutdown, it issues to the network a detach request that informs the network that the device will not be reachable any more.

TIP:

To check if the device has powered off, hardware line PWRMON must be monitored. When PWRMON goes low it can be considered the device has powered off.

NOTE:

In order 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.

1vv0301026 Rev.8 2015-01-03

4.3.1. Shutdown by Software Command

LE920 can be shut down by a software command.

When a shutdown command is sent, LE920 goes into the finalization state and finally will shut down PWRMON at the end of this state.

The duration of the finalization state can differ according to the situation in which the LE920 is, so a value cannot be defined.

Normally it will be more than15 seconds after sending a shutdown command, DTE should monitor the status of PWRMON to observe the actual power off.

LE920 Hardware User Guide

TIP:

To check if the device has powered off, hardware line PWRMON must be monitored. When PWRMON goes low, the device has powered off.

4.3.2. Hardware Shutdown

To turn OFF LE920 the pad ON/OFF# must be tied low for at least 2 seconds and then released. The same circuitry and timing for the power on must be used.

When the hold time of ON/OFF# is above 2.5 seconds, LE920 goes into the finalization state and finally will shut down PWRMON at the end of this state.

The period of the finalization state can differ according to the situation in which the LE920 is, so it cannot be fixed definitely.

. Normally it will be more than15 seconds after sending a shutdown command ; DTE should monitor the status of PWRMON to see observe the actual power off.

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

TIP:

To check if the device has powered off, hardware line PWRMON must be monitored. When PWRMON goes low, the device has powered off.

NOTE:

Do not use any pull up resistor on the RESET# line or any totem pole digital output. Using pull up resistor may cause latch-up problems on the LE920 power regulator and improper functioning of the module. The line RESET# must be connected only in open collector configuration.

NOTE:

Asserting tRESET low for period greater than 2000 milliseconds will cause the module to shut down.

TIP:

The unconditional hardware Restart must always be implemented on the boards and the software must use it only as an emergency exit procedure, and not as a normal power-off operation

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

4.3.3. Hardware Unconditional Restart (RESET)

To unconditionally restart LE920, the pad RESET# must be tied low for period between 500 2000 milliseconds and then released.

A simple circuit to do it is:

NOTE:

Do not use any pull up resistor on the SHDN_N line or any totem pole digital output. Using pull up resistor may cause latch-up problems on the LE920 power regulator and improper functioning of the module. The line SHDN_N must be connected only in open collector configuration.

NOTE:

The unconditional hardware SHDN_N must always be implemented on the boards. The software must use it as an emergency exit procedure only, and not as a normal power-off operation.

1vv0301026 Rev.8 2015-01-03

4.3.4. Hardware Unconditional Shutdown

To unconditionally Shutdown LE920, the pad SHDN_N must be tied low for at least 200 milliseconds and then released.

A simple circuit to do it is:

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

4.4. Summary of Turning ON and OFF the module

The chart below describes the overall sequences for Turning ON and OFF.

Power Supply

Nominal Supply Voltage

3.8V

Max Supply Voltage

4.2V

Supply Voltage Range

3.3V– 4.2V

LE920 current consumption

Mode

Average(mA)

Mode Description

SWITCHED OFF

Module supplied but switched Off

Switched Off

40 uA

IDLE mode

Standby mode; no call in progress

AT+CFUN=1

WCDMA

Normal mode; full functionality of the module

GSM

LTE

AT+CFUN=4

Disabled TX and RX; modules is not registered on the network

AT+CFUN=5

GSM

4.4

DRx2

3.3

DRx3

2.8

DRx4

2.5

DRx5

2.3

DRx6

2.1

DRx7

2.0

DRx8

1.9

DRx9

WCDMA

3.0

DRx6

2.2

DRx7

1.8

DRx8

1.4

DRx9

LTE

6.3

Paging cycle #32 frames (0.32 sec DRx cycle)

3.8

Paging cycle #64 frames (0.64 sec DRx cycle)

1vv0301026 Rev.8 2015-01-03

5. Power Supply

The power supply circuitry and board layout are a very important part in the full product design and they strongly reflect on the overall product performance. Reading carefully the requirements and the guidelines that follow will ensure a good and proper design.

5.1. Power Supply Requirements

The LE920 power requirements are:

LE920 Hardware User Guide

2.5

Paging cycle #128 frames (1.28 sec DRx cycle)

1.9

Paging cycle #256 frames (2.56 sec DRx cycle)

Operative mode (LTE)

LTE (0dBm)

203

LTE data call channel BW 5MHz,RB=1, TX = 0dBm)

LTE (22dBm)

540

LTE data call (channel BW 5MHz,RB=1, TX = 22dBm)

Operative mode (WCDMA)

WCDMA Voice

185

WCDMA voice call (TX = 10dBm)

WCDMA HSDPA (0dBm)

170

WCDMA data call (Cat 14, TX = 0dBm, Max Throughput)

WCDMA HSDPA (22dBm)

470

WCDMA data call (Cat 14, TX = 22dBm, Max Throughput)

Operative mode (GSM)

GSM TX and RX mode

GSM900 PL5

290

GSM Voice Call

DCS1800 PL0

170

GPRS 4TX + 1RX

GSM900 PL5

410

GPRS Sending data mode

DCS1800 PL0

320

EDGE 4TX + 1RX

GSM900 PL5

255

EDGE Sending data mode

DCS1800 PL0

240

NOTE:

In GSM/GPRS mode, RF transmission is not continuous and is packed into bursts at a base frequency of about 216 Hz with relative current peaks as high as about 2A. Therefore the power supply must be designed to withstand these current peaks without big voltage drops; this means that both the electrical design and the board layout must be designed for this current flow. If the layout of the PCB is not well designed, a strong noise floor is generated on the ground. This will reflect on all the audio paths producing an audible annoying noise at 216 Hz; if the voltage drops during the peaks, current absorption is too high. The device may even shut down as a consequence of the supply voltage drop.

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

* Worst/best case depends on network configuration and is not under module control.

TIP:

The electrical design for the Power supply must be made ensuring that it will be capable of a peak current output of at least 2A.

1vv0301026 Rev.8 2015-01-03

5.2. General Design Rules

The principal guidelines for the Power Supply Design embrace three different design steps:

 the electrical design

 the thermal design

 the PCB layout

5.2.1. Electrical Design Guidelines

The electrical design of the power supply depends strongly on the power source where this power is drained. We will distinguish them into three categories:

 +5V input (typically PC internal regulator output)

 +12V input (typically automotive)

 battery

LE920 Hardware User Guide

5.2.1.1. + 5V Input Source Power Supply Design Guidelines

 The desired output for the power supply is 3.8V, hence there is not a big

difference between the input source and the desired output and a linear regulator can be used. A switching power supply will not be suitable because of the low drop-out requirements.

 When using a linear regulator, a proper heat sink must be provided in order to

dissipate the power generated.

 A Bypass low ESR capacitor of adequate capacity must be provided in order to

cut the current absorption peaks close to LE920, a 100μF tantalum capacitor is usually suitable (on both VBATT and VBATT_PA together)..

 Make sure 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, in order to protect

LE920 from power polarity inversion.

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

An example of linear regulator with 5V input is:

5.2.1.2. + 12V Input Source Power Supply Design Guidelines

 The desired output for the power supply is 3.8V, hence due to the big difference

between the input source and the desired output, a linear regulator is unsuitable and must not be used. A switching power supply will be preferable because of its better efficiency especially with the 2A peak current load represented by LE920.

 When using a switching regulator, a 500 kHz or more switching frequency

regulator is preferable because of its smaller inductor size and its faster transient response. This allows the regulator to respond quickly to the current peaks absorption.

 In any case, the frequency and switching design selection is related to the

application to be developed due to the fact the switching frequency could also generate EMC interference.

 For car batteries (lead-acid accumulators) the input voltage can rise up to 15.8V

and this must be kept in mind when choosing components: all components in the power supply must withstand this voltage.

 A bypass low ESR capacitor of adequate capacity must be provided in order to

cut the current absorption peaks. A 100μF tantalum capacitor is usually suitable (on both VBATT and VBATT_PA together).

 Make sure the low ESR capacitor on the power supply output (usually a tantalum

one) is rated at least 10V.

 For automotive applications a spike protection diode must be inserted close to the

power input, in order to clean the supply of spikes.

 A protection diode must be inserted close to the power input, in order to protect

LE920 from power polarity inversion. This can be the same diode as for spike protection.

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

An example of switching regulator with 12V input is in the below schematic (it is split in 2 parts):

Switching regulator

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

5.2.1.3. Battery Source Power Supply Design Guidelines

 The desired nominal output for the power supply is 3.8V and the maximum allowed

voltage is 4.2V, hence a single 3.7V Li-Ion cell battery type is suited for supplying the power to the Telit LE920 module.

NOTE:

Do not use any Ni-Cd, Ni-MH, and Pb battery types directly connected with LE920. Their use can lead to overvoltage on LE920 and damage it. Use only Li-Ion battery types.

 A bypass low ESR capacitor of adequate capacity must be provided in order to

cut the current absorption peaks; a 100μF tantalum capacitor is usually suitable (on both VBATT and VBATT_PA together).

 Make sure the low ESR capacitor (usually a tantalum one) is rated at least 10V.

 A protection diode must be inserted close to the power input, in order to protect

LE920 from power polarity inversion. Otherwise the battery connector must be done in a way to avoid polarity inversions when connecting the battery.

 The battery capacity must be at least 900mAh in order to withstand the current

peaks of 2A.

5.2.2. Thermal Design Guidelines

The thermal design for the power supply heat sink must be done with the following specifications:

 Average current consumption during HSPA transmission @PWR level max in

LE920: 640mA (TBD)

 Average current consumption during class12 GPRS transmission @PWR level

max: 680mA (TBD)

 Average GPS current during GPS ON (Power Saving disabled) : 65mA (TBD)

NOTE:

The average consumption during transmissions depends on the power level at which the device is requested to transmit via the network. The average current consumption hence varies significantly.

LE920 Hardware User Guide

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NOTE:

The thermal design for the Power supply must be made keeping an average consumption at the max transmitting level during calls of 640mA(HSPA)/680mA(GPRS) rms plus 65mA rms for GPS in tracking mode.

Considering the very low current during idle, especially if Power Saving function is enabled, it is possible to consider from the thermal point of view that the device absorbs significant current only during calls.

If we assume that the device stays in transmission for short periods of time (let us say few minutes) and then remains for quite a long time in idle (let us say one hour), then the power supply always has time to cool down between calls and the heat sink could be smaller than the calculated for 640mA (HSPA)/680mA (GPRS) maximum RMS current. There could even be a simple chip package (no heat sink).

Moreover in average network conditions the device is requested to transmit at a lower power level than the maximum and hence the current consumption will be less than 640mA (HSPA) /680mA (GPRS) (being usually around 250mA).

For these reasons the thermal design is rarely a concern and the simple ground plane where the power supply chip is placed can be enough to ensure a good thermal condition and avoid overheating.

For the heat generated by the LE920, you can consider it to be during transmission 2W max during class12 GPRS upload. This generated heat will be mostly conducted to the ground plane under the LE920; you must ensure that your application can dissipate heat.

In the WCDMA/HSPA mode, since LE920 emits RF signals continuously during transmission, you must pay special attention how to dissipate the heat generated.

The current consumption will be up to about 640mA in HSPA (630mA in WCDMA) continuously at the maximum TX output power (23dBm). Thus you must arrange on the PCB used to mount LE920, that the area under LE920 is as large as possible. You must mount LE920 on the large ground area of your application board and make many ground vias to dissipate the heat.

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Even though peak current consumption in GSM mode is higher than in WCDMA, consideration for the heat sink is more important in the case of WCDMA.

As mentioned before, a GSM signal is bursty, thus, the temperature drift is more insensitive than WCDMA. Consequently, if you successfully manage heat dissipation in WCDMA mode, you don’t need to think more about GSM mode.

5.2.3. 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 is crucial for the correct working 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 Telit LE920 power

input pads, or in the case the power supply is 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 LE920 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 no voltage drops occur during the 2A current peaks. Note that this is not done to save power loss but especially to avoid the voltage drops on the power line at the current peaks frequency of 216 Hz that will reflect on all the components connected to that supply (also introducing the noise floor at the burst base frequency.) For this reason while a voltage drop of 300-400 mV may be acceptable from the power loss point of view, the same voltage drop may not be acceptable from the noise point of view. If your application does not have audio interface but only uses the data feature of the Telit LE920, then this noise is not so disturbing and power supply layout design can be more forgiving.

 The PCB traces to LE920 and the bypass capacitor must be wide enough to

ensure no significant voltage drops occur when the 2A current peaks are absorbed. This is needed for the same above-mentioned reasons. Try to keep this trace 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 switching power supply). This is done in order to reduce the radiated field (noise) at the switching frequency (usually 100-500 kHz).

 The use of a good common ground plane is suggested.

 The placement of the power supply on the board must be done in a way to

guarantee that the high current return paths in the ground plane are not overlapping any noise sensitive circuitry such as the microphone amplifier/buffer or earphone amplifier.

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 The power supply input cables must be kept separate from noise sensitive lines

such as microphone/earphone cables.

Antenna Line on PCB Requirements

GSM / WCDMA/ LTE Antenna Requirements

Frequency

range

Depending on frequency band(s) provided by the network operator, the customer must use the most suitable antenna for that/those band(s)

Bandwidth

LE920-EU

LE920-NAG

LE920-NA

GSM850 : 70 MHz GSM900 : 80 MHz GSM1800(DCS) : 170 MHz GSM1900(PCS) : 140 MHz WCDMA band I(2100) : 250 MHz WCDMA band III(1800) : 170 MHz WCDMA band VIII(900) : 80 MHz LTE Band I(2100) : 250 MHz LTE band III(1800) : 170 MHz LTE Band VII(2600) : 190 MHz LTE Band VIII(900) : 80 MHz LTE Band XX(800) : 71 MHz

GSM850 : 70 MHz GSM900 : 80 MHz GSM1800(DCS) : 170 MHz GSM1900(PCS) : 140 MHz WCDMA band I(2100) : 250 MHz WCDMA band II(1900) : 140 MHz WCDMA band IV(1700) : 445 MHz WCDMA band V(850) : 70 MHz WDCMA band VI(800): 70MHz LTE Band I(2100) : 250 MHz LTE Band II(1900) : 140 MHz LTE Band IV(1700) : 445 MHz LTE Band V (850) : 70 MHz LTE Band XVII(700) : 42 MHz

GSM850 : 70 MHz GSM1900(PCS) : 140 MHz WCDMA band II(1900) : 140 MHz WCDMA band IV(1700) : 445 MHz WCDMA band V(850) : 70 MHz LTE Band II(1900) : 140 MHz LTE Band IV(1700) : 445 MHz LTE Band V (850) : 70 MHz LTE Band VII(2600) : 190 MHz LTE Band XVII(700) : 42 MHz LTE Band XII(700) : 42 MHz

Gain

Gain < 3dBi

Impedance

50 Ohm

Input power

> 33dBm(2 W) peak power in GSM > 24dBm Average power in WCDMA & LTE

VSWR

absolute max

<= 10:1

VSWR

recommended

<= 2:1

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6. Antenna(s)

The antenna connection and board layout design are the most important parts in the full product design and they strongly reflect on the product’s overall performance. Read carefully and follow the requirements and the guidelines for a good and proper design.

6.1. GSM/WCDMA/LTE Antenna Requirements

The antenna for a Telit LE920 device must fulfill the following requirements:

When using the Telit LE920, since there’s no antenna connector on the module, the antenna must be connected to the LE920 antenna pad (AD1) by means of a transmission line implemented on the PCB.

In the case that the antenna is not directly connected to the antenna pad of the LE920, then a PCB line is required in order to connect with it or with its connector.

This transmission line shall fulfill the following requirements:

Characteristic Impedance

50Ohm

Max Attenuation

0.3dB

Coupling with other signals shall be avoided

Cold End (Ground Plane) of antenna shall be equipotential to the LE920 ground pads

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Furthermore if the device is developed for the US and/or Canada market, it must comply with the FCC and/or IC approval requirements:

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 LE920 module. Antennas used for this OEM module must not exceed 3dBi gain for mobile and fixed operating configurations.

6.2. GSM/WCDMA/LTE Antenna – PCB line Guidelines

 Make sure that the transmission line’s characteristic impedance is 50ohm.  Keep the line on the PCB as short as possible since the antenna line loss should be less

than around 0.3dB.

 Line geometry should have uniform characteristics, constant cross section, avoid

meanders and abrupt curves.

 Any suitable geometry/structure can be used for implementing the printed transmission

line affecting the antenna.

 If a Ground plane is required in the line geometry, that plane must be continuous and

sufficiently extended so the geometry can be as similar as possible to the related canonical model.

 Keep, if possible, at least one layer of the PCB used only for the Ground plane; if possible,

use this layer as reference Ground plane for the transmission line.

 It is wise to surround (on both sides) the PCB transmission line with Ground. Avoid

having other signal tracks facing directly the antenna line track.

 Avoid crossing any un-shielded transmission line footprint with other tracks on different

layers.

 The Ground surrounding the antenna line on the PCB must be strictly connected to the

main Ground plane by means of via-holes (once per 2mm at least) placed close to the ground edges facing the line track.

 Place EM-noisy devices as far as possible from LE920 antenna line.  Keep the antenna line far away from the LE920 power supply lines.  If EM-noisy devices are present on the PCB hosting the LE920, such as fast switching

ICs, take care to shield them with a metal frame cover.

 If EM-noisy devices are not present around the line, using geometries like Micro strip or

Grounded Coplanar Waveguide is preferred since they typically ensure less attenuation compared to a Strip line having the same length.

ANTENNA REQUIREMENTS

Frequency range

Depending on frequency band(s) provided by the network operator, the customer shall use the most suitable antenna for that/those band(s)

Bandwidth

LE920-EU

LE920-NA

WCDMA band I(2100) : 250 MHz WCDMA band III(1800) : 170 MHz WCDMA band VIII(900) : 80 MHz LTE Band I(2100) : 250 MHz LTE band III(1800) : 170 MHz LTE Band VII(2600) : 190 MHz LTE Band VIII(900) : 80 MHz LTE Band XX(800) : 71 MHz

WCDMA band I(2100) : 250 MHz WCDMA band II(1900) : 140 MHz WCDMA band IV(AWS) : 445 MHz WCDMA band IV(850) : 445 MHz WCDMA band V(850) : 70 MHz WDCMA band VI(800): 55MHz LTE Band I(2100) : 250 MHz LTE Band II(1900) : 140 MHz LTE Band IV(1700) : 445 MHz LTE Band V (850) : 70 MHz Band XVII(700) : 42 MHz Band XII(700) : 42 MHz

Impedance

50Ω

VSWR recommended

≤ 2:1

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6.3. GSM/WCDMA/LTE 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 also be installed according to the antenna manufacturer’s

instructions.

6.4. Antenna Diversity Requirements

This product includes an input for a second RX antenna to improve the radio sensitivity. The function is called Antenna Diversity.

When using the Telit LE920, since there’s no antenna connector on the module, the antenna must be connected to the LE920 antenna pad (AU9) by means of a transmission line implemented on the PCB.

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In the case that the antenna is not directly connected at the antenna pad of the LE920, then a PCB line is required in order to connect with it or with its connector.

The second Rx antenna should not be located in the close vicinity of the 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 within the application.

NOTE:

If the RX Diversity is not used/connected, disable the Diversity functionality using the AT#RXDIV command (refer to the AT User guide) and leave the Diversity pad AU9 unconnected.

6.5. GPS/GNSS Antenna Requirements

LE920 supports an active antenna.

It is recommended to use antennas as follow:

 An external active antenna (GPS only).  An external active antenna, GNSS pre-filter.

NOTE:

Released models LE920-NA cs1550f-A & LE920-EU cs1550f-B include internal LNA (13.5dB gain typ.).

For LE920-NA cs1550f-A & LE920-EU cs1550f-B models it is recommended to use:

• An external passive antenna (GPS only).

• An external passive antenna, GNSS pre-filter.

NOTE:

The external GNSS pre-Filter shall be required for GLONASS application.

GNSS pre-Filter requirement shall fulfill the following requirements.

 Source and Load Impedance = 50Ohm

 Insertion Loss (1575.42 – 1576.42MHz) = 1.4dB (Max)

 Insertion Loss (1565.42 – 1585.42MHz) = 2.0dB (Max)

 Insertion Loss (1597.5515 – 1605.886MHZ) = 2.0dB (Max)

Antenna Line on PCB Requirements

Characteristic Impedance

50Ohm

Max Attenuation

0.3dB

Coupling with other signals shall be avoided

Cold End (Ground Plane) of antenna shall be equipotential to the LE920 ground pads

NOTE:

It is recommended to add a DC block to the customer’s GPS application in order to prevent damage to the LE920 due to unwanted DC voltage

WARNING:

The LE920 software is implemented differently depending on the configurations of an external device. Please refer to the AT command User Guide in detail.

6.5.1. Combined GPS/GNSS Antenna

The use of combined RF/GPS/GNSS antenna is NOT recommended. This solution could generate extremely poor GPS/GNSS reception. In addition, the combination of antennas requires an additional diplexer, which adds significant power losses in the RF path.

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6.5.2. Linear and Patch GPS/GNSS Antenna

Using this type of antenna introduces at least 3dB of loss compared to a circularly polarized (CP) antenna. Having a spherical gain response instead of a hemispherical gain response could aggravate the multipath behaviour & create poor position accuracy.

6.5.3. Front End Design Considerations

When using the Telit LE920, since there’s no antenna connector on the module, the antenna must be connected to the LE920 through the PCB to the antenna pad.

In the case that the antenna is not directly connected at the antenna pad of the LE920, then a PCB line is required.

This line of transmission shall fulfill the following requirements:

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Furthermore if the device is developed for the US and/or Canada market, it must comply with the FCC and/or IC requirements.

This device is to be used only for mobile and fixed application.

6.5.4. GPS/GNSS Antenna - PCB Line Guidelines

 Ensure that the antenna line impedance is 50ohm.  Keep the line on the PCB as short as possible to reduce the loss.  The antenna line must have uniform characteristics, constant cross section, avoiding

meanders and abrupt curves.

 Keep one layer of the PCB used only for the Ground plane; if possible.  Surround (on the sides, over and under) the antenna line on the PCB with Ground. Avoid

having other signal tracks directly facing the antenna line track.

 The Ground around the antenna line on the PCB must be strictly connected to the main

Ground plane by placing vias at least once per 2mm.

 Place EM-noisy devices as far as possible from LE920 antenna line.  Keep the antenna line far away from the LE920 power supply lines.

 If EM-noisy devices are around the PCB hosting the LE920, such as fast switching ICs,

ensure shielding the antenna line by burying it inside the layers of PCB and surrounding it with Ground planes; or shield it with a metal frame cover.

 If you do not have EM-noisy devices around the PCB of LE920, use a Micro strip line

on the surface copper layer for the antenna line. The line attenuation will be lower than a buried one.

6.5.5. GPS/GNSS Antenna – Installation Guidelines

 The LE920, due to its sensitivity characteristics, is capable of performing a fix inside

buildings. (In any case the sensitivity could be affected by the building characteristics i.e. shielding)

 The antenna must not be co-located or operating in conjunction with any other antenna

or transmitter.

 The antenna shall not be installed inside metal cases.  The antenna shall also be installed according to the antenna manufacturer’s instructions.

Parameter

LE920

Min

Max

Input level on any digital pin when on

-0.3V

+2.16V

Input voltage on analog pins when on

-0.3V

+2.16 V

Level

LE920

Min

Max

Input high level

1.5V

2.1V

Input low level

-0.3V

0.5V

Output high level

1.35V

1.8V

Output low level

0.45V

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7. Logic Level Specifications

Where not specifically stated, all the interface circuits work at 1.8V CMOS logic levels.

The following table shows the logic level specifications used in the Telit LE920 interface circuits:

NOTE:

Do not connect LE920’s digital logic signal directly to OEM’s digital logic signal with a level higher than 2.7V for 1.8V CMOS signals.

For 1.8V CMOS signals:

Absolute Maximum Ratings - Not Functional

Operating Range - Interface levels (1.8V CMOS)

Signal

LE920

Pad No.

Usage

USB_VBUS

A18

Power sense for the internal USB transceiver. Acceptable input voltage range 2.2V – 5.25V @ max 5mA consumption

USB_D-

F19

Minus (-) line of the differential, bi-directional USB signal to/from the peripheral device

USB D+

D19

Plus (+) line of the differential, bi-directional USB signal to/from the peripheral device

8. USB Port

The LE920 module includes a Universal Serial Bus (USB) transceiver, which operates at USB high-speed (480Mbits/sec). It can also work with USB full-speed (12Mbits/sec) hosts

It is compliant with the USB 2.0 specification and can be used control and data transfers as well as for diagnostic monitoring and firmware update. In fact firmware update by the host is only possible via USB and not possible via UART. The reason is that Telit consider it impractical to transfer firmware binaries exceeding 100Mb via UART.

The USB port on the Telit LE920 is typically the main interface between the module and OEM hardware.

The USB_DPLUS and USB_DMINUS signals have a clock rate of 480MHz. The signal traces should be routed carefully. Trace lengths, number of vias and capacitive loading should be minimized. The impedance value should be as close as possible to 90 Ohms differential.

The table below describes the USB interface signals:

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NOTE:

- USB_VBUS input power is internally used to detect the USB port and start enumeration

process. It isn’t used for supplying internal LE920 USB HW block. Therefore, only maximum of 5mA is required.

- The USB_VBUS is internally pulled-down by 10k ohm resistor. Customer host

application must take into account voltage divider with the internal pull down resistor meeting the minimum of 2.2V input, in case that a serial resistor is placed on USB_VBUS signal.

NOTE:

In the case of not using USB communication, it is still highly recommended to place an optional USB connector in the application board.

USB physical communication is needed in the case of SW update

Parameter

LE920

Min

Max

Input level on any digital pin when on

-0.3V

+2.16 V

Input voltage on analog pins when on

-0.3V

+2.16 V

Level

LE920

Min

Max

Input high level

1.5V

2.1V

Input low level

-0.3V

0.5V

Output high level

1.35V

1.8V

Output low level

0.45V

9. Serial Ports

The serial port on the Telit LE920 is typically a secondary interface between the module and OEM hardware.

Two serial ports are available on the module:

 MODEM SERIAL PORT 1(Main)

 MODEM SERIAL PORT 2 (Auxiliary)

Several configurations can be designed for the serial port on the OEM hardware.

The most common are:

 RS232 PC com port;

 Microcontroller UART @ 1.8V (Universal Asynchronous Receive Transmit) ;

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 Microcontroller UART @ 5V or other voltages different from 1.8V.

Depending on the type of serial port on the OEM hardware, a level translator circuit may be needed to make the system work. The only configuration that does not need a level translation is the 1.8V UART.

The serial port 1 on LE920 is a +1.8V UART with all the 7 RS232 signals. It differs from the PC-RS232 in signal polarity (RS232 is reversed) and levels.

The Serial port 2 is a +1.8V Auxiliary UART.

The levels for LE920 UART are the CMOS levels:

Absolute Maximum Ratings -Not Functional

Operating Range - Interface levels

RS232

Number

Signal

LE920

Pad Number

Name

Usage

DCD -

dcd_uart

AE18

Data Carrier Detect

Output from the LE920 that indicates the carrier presence

RXD -

Tx_uart

AF19

Transmit line *see Note

Output transmit line of the LE920 UART

TXD -

Rx_uart

AH19

Receive line *see Note

Input receive of the LE920 UART

DTR -

dtr_uart

AC18

Data Terminal Ready

Input to the LE920 that controls the DTE READY condition

GND

A6, A12, B13, B15….

Ground

ground

DSR -

dsr_uart

AG18

Data Set Ready

Output from the LE920 that indicates the module is ready

RTS -

rts_uart

AA18

Request to Send

Input to the LE920 that controls the Hardware flow control

CTS -

cts_uart

AK19

Clear to Send

Output from the LE920 that controls the Hardware flow control

RI -

ri_uart

AJ18

Ring Indicator

Output from the LE920 that indicates the Incoming call condition

9.1. Modem Serial Port 1

Serial port 1 on the LE920 is a +1.8V UART with all 7 RS232 signals.

It differs from the PC-RS232 in the signal polarity (RS232 is reversed) and levels.

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NOTE:

In order 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.

TIP:

For minimum implementations, only the TXD and RXD lines need be connected, the other lines can be left open provided a software flow control is implemented.

NOTE:

According to V.24, RX/TX signal names are referred to the application side, therefore on the LE920 side these signal are in the opposite direction: TXD on the application side will be connected to the receive line (here named TXD/ rx_uart ) of the LE920 serial port and vice versa for RX.

PAD

Signal

I/O

Function

Type

COMMENT

AB19

TXD_AUX

Auxiliary UART (TX Data to DTE)

1.8V

AD19

RXD_AUX

Auxiliary UART (RX Data to DTE)

1.8V

9.2. Modem Serial Port 2

Serial port 2 on the LE920 is a +1.8V UART with only the RX and TX signals.

The signals of the LE920 serial port are:

NOTE:

In order 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.

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9.3. RS232 Level Translation

In order to interface the Telit LE920 with a PC com port or a RS232 (EIA/TIA-232) application a level translator is required. This level translator must:

 Invert the electrical signal in both directions;

 Change the level from 0/1.8V to +15/-15V.

Actually, the RS232 UART 16450, 16550, 16650 & 16750 chipsets accept signals with lower levels on the RS232 side (EIA/TIA-562), allowing a lower voltage-multiplying ratio on the level translator. Note that the negative signal voltage must be less than 0V and hence some sort of level translation is always required.

The simplest way to translate the levels and invert the signal is by using a single chip level translator. There are a multitude of them, differing in the number of drivers and receivers and in the levels (be sure to get a true RS232 level translator not a RS485 or other standards).

By convention the driver is the level translator from the 0-1.8V UART to the RS232 level. The receiver is the translator from the RS232 level to 0-1.8V UART.

In order to translate the whole set of control lines of the UART you will need:

 5 drivers

 3 receivers

NOTE:

The digital input lines working at 1.8V CMOS have an absolute maximum input voltage of

2.7V; therefore the level translator IC shall not be powered by the +3.8V supply of the module. Instead, it must be powered from a +1.8V (dedicated) power supply.

This is because in this way the level translator IC outputs on the module side (i.e. LE920 inputs) will work at +3.8V interface levels, damaging the module inputs.

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An example of RS232 level adaption circuitry could be accomplished using a MAXIM transceiver (MAX218).

In this case the chipset is capable of translating directly from 1.8V to the RS232 levels (Example on 4 signals only).

NOTE:

In this case the length of the lines on the application must be taken into account to avoid problems in the case of High-speed rates on RS232.

The RS232 serial port lines are usually connected to a DB9 connector with the following layout: signal names and directions are named and defined from the DTE point of view

PAD

Signal

I/O

Function

Type

COMMENT

P19

SPI_CLK

SPI Clock output

1.8V

M19

SPI_MISO

SPI data Master Input Slave output

1.8V

K19

SPI_MOSI

SPI data Master Output Slave input

1.8V

N18

SPI_CS

SPI Chip select output

1.8V

LE920 (Master)

SPI_CS

SPI_CLK

SPI_MOSI

SPI_MISO

Host (Slave)

SPI_CS

SPI_CLK

SPI_MOSI

SPI_MISO

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10. Peripheral Ports

In addition to Telit LE920 serial ports, the LE920 supports the following peripheral ports:

 SPI – Serial Peripheral Interface

 I2C - Inter-integrated circuit

 2 x SDIO – Secure Digital I/O

10.1. SPI – Serial Peripheral Interface

The LE920 SPI supports the following:

 Master Mode only

 1.8V CMOS level

 Up to 26MHz clock rate

NOTE:

SPI is supported only on the Linux side.

LE920 can support Master mode only, and can’t be configured as slave mode.

PAD

Signal

I/O

Function

Type

COMMENT

AH17

SD/MMC_CMD

SD Command

1.8/2.95V

AD17

SD/MMC_CLK

SD Card Clock

1.8/2.95V

Y17

SD/MMC_DATA0

I/O

SD Serial Data 0

1.8/2.95V

AF17

SD/MMC_DATA1

I/O

SD Serial Data 1

1.8/2.95V

AB17

SD/MMC_DATA2

I/O

SD Serial Data 2

1.8/2.95V

W17

SD/MMC_DATA3

I/O

SD Serial Data 3

1.8/2.95V

U17

SD/MMC_CD

SD card detect input

1.8V

Active Low

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10.2. I2C - Inter-integrated circuit

The LE920 I2C is an alternate function of our GPIO 1-10 pins.

Any GPIO can be configured as SCL and SDA

Available only from Modem side as SW emulation of I2C on GPIO lines.

LE920 supports I2C Master Mode only.

NOTE:

I2C is supported only on from Modem side as SW emulation of I2C on GPIO lines.

Refer to LE920 AT SW manual for command settings

10.3. SDIO – Secure Digital I/O

The LE920 is used to support standard SD/MMC memory cards with the following:

 Interface with SD/MMC memory cards up to 2 TB

 Max clock: 50 MHz SDR at 1.8 V, Max Data: 25MB/s, MMC standard: MMC 4.4

type 3 SDR at 1.8 V; SD standard: UHS-SDR25 at 1.8 V

 Max clock: 50 MHz SDR at 2.95 V, Max Data: 25MB/s, MMC standard: MMC

4.4 type 3 SDR at 2.95 V; SD standard: DS, HS at 2.95

SD/MMC_DATA2

SD/MMC_DATA3

SD/MMC_CMD

SD/MMC_CLK

SD/MMC_DATA0

SD/MMC_DATA1

LE920

SDIO Interface

SD/MMC_CD

Ext, Card supply

DATA2

DATA3

CMD

VDD

CLK

VSS

DATA0

DATA1

microSD

SW1

SW2

GND

10K

C=100nF

GND

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Connection diagram of the SD interface is shown below:

NOTE:

1. SDIO is supported only on the Linux side.

2. SD/MMC card supply shall be provided by the Host application board. LE920 doesn’t

provide a dedicated SD/MMC card supply.

3. Pull-up resistors should be place on the application host board

4. Card detection input has an internal pull-up resistor

PAD

Signal

I/O

Function

Type

COMMENT

AB3

WiFi_SD_CMD

Wi-Fi SD Command

1.8V

AM3

WiFi_SD_CLK

Wi-Fi SD Clock

1.8V

AD3

WiFi_SD _DATA0

I/O

Wi-Fi SD Serial Data 0

1.8V

AF3

WiFi_SD _DATA1

I/O

Wi-Fi SD Serial Data 1

1.8V

AH3

WiFi_SD _DATA2

I/O

Wi-Fi SD Serial Data 2

1.8V

AK3

WiFi_SD _DATA3

I/O

Wi-Fi SD Serial Data 3

1.8V

WiFi_RST_Ctr

Wi-Fi Reset output control / Power enable control

1.8V

Active Low

LE920 Hardware User Guide

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10.4. Wi-Fi (SDIO) control Interface

The LE920 has an integrated SW driver for supporting Qualcomm QCA6053 Wi-Fi chipset via a 2nd dedicated SD bus interface.

The secondary SD bus interface can be used only with the QCA6053 chipset, and can’t be used as external SD/MMC card connection.

For detailed explanation, refer to Telit 80407NT11289A - xE920 - Wi-Fi interface Application Note

WARNING:

Wi-Fi (SDIO) control interface is fully supported in LE920-EU and LE920-NA.

However, in some cases isn’t supported in LE920-EUG and LE920-NAG.

If Wi-Fi control is required for LE920-NAG or LE920-NAG, please contact your local Telit rep. or contact customer support for specific ordering info.

NOTE:

‘Wifi_RST_Ctr’ should have an optional Pull-up resistor to 1.8V on the host application, to disable Wi-Fi reset function if needed

PAD

Signal

I/O

Function

Type

COMMENT

D11

DVI_WA0

Digital Audio Interface (WA0)

B-PD

1.8V

PCM_SYNC

DVI_RX

Digital Audio Interface (RX)

B-PD

1.8V

PCM_DIN

DVI_TX

Digital Audio Interface (TX)

B-PD

1.8V

PCM_DOUT

C10

DVI_CLK

Digital Audio Interface (CLK)

B-PD

1.8V

PCM_CLK

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11. Audio Section Overview

The LE920 module support analog and digital audio interfaces.

11.1. Analog Audio

The LE920 module provides single analog audio path transmitting and receiving.

Please refer to the xE920_Audio_Settings_Application_Note, 80404NT10095A

WARNING:

LE920 Analog audio implementation uses an internal CODEC. LE920 internal codec uses the same external LE920 digital Audio interface signals Therefore, applications that are using analog audio, must make sure that the digital audio interface shall be either not connected, or Hi-Z, or ‘input’ to Host application.

LE920 Hardware User Guide

11.2. Digital Audio

LE920 can be connected to an external codec through the digital interface.

The product provides one Digital Audio Interface (DVI) on the following Pins:

LE920 DVI supports PCM master 2048khz short frame

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PAD

Signal

I/O

Function

Type

Drive Strength

GPIO_01

I/O

Configurable GPIO

CMOS 1.8V

2mA

E10

GPIO_02

I/O

Configurable GPIO

CMOS 1.8V

2mA

F11

GPIO_03

I/O

Configurable GPIO

CMOS 1.8V

2mA

E12

GPIO_04

I/O

Configurable GPIO

CMOS 1.8V

2mA

F13

GPIO_05

I/O

Configurable GPIO

CMOS 1.8V

2mA

E14

GPIO_06

I/O

Configurable GPIO

CMOS 1.8V

2mA

R18

GPIO_07

I/O

Configurable GPIO

CMOS 1.8V

2mA

S19

GPIO_08

I/O

Configurable GPIO

CMOS 1.8V

2mA

U19

GPIO_09

I/O

Configurable GPIO

CMOS 1.8V

2mA

W19

GPIO_10

I/O

Configurable GPIO

CMOS 1.8V

2mA

12. General Purpose I/O

The general-purpose I/O pads can be configured to act in three different ways:

 input

 output

 alternate function (internally controlled)

Input pads can only be read and report the digital value (high or low) present on the pad at the read time; output pads can only be written or queried and set the value of the pad output; an alternate function pad is internally controlled by the LE920 firmware and acts depending on the function implemented.

The following GPIOs are available on the LE920.

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NOTE:

In order 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.

NOTE:

LE920 GPIO can also be used as alternate I2C function. Refer to I2C section

Parameter

LE920

Min

Max

Input level on any digital pin when on

-0.3V

+2.16 V

Input voltage on analog pins when on

-0.3V

+2.16 V

Level

LE920

Min

Max

Input high level

1.5V

2.1V

Input low level

-0.3V

0.5V

Output high level

1.35V

1.8V

Output low level

0.45V

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12.1. Logic Level Specifications

Where not specifically stated, all the interface circuits work at 1.8V CMOS logic levels.

The following table shows the logic level specifications used in the LE920 interface circuits:

For 1,8V signals:

Absolute Maximum Ratings -Not Functional

LE920 Hardware User Guide

Operating Range - Interface levels (1.8V CMOS)

12.2. Using a GPIO Pad as Input

The GPIO pads, when used as inputs, can be connected to a digital output of another device and report its status, provided this device has interface levels compatible with the 1.8V CMOS levels of the GPIO.

If the digital output of the device is connected with the GPIO input, the pad has interface levels different from the 1.8V CMOS. It can be buffered with an open collector transistor with a 47KΩ pull-up resistor to 1.8V.

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12.3. Using a GPIO Pad as Output

The GPIO pads, when used as outputs, can drive 1.8V CMOS digital devices or compatible hardware. When set as outputs, the pads have a push-pull output and therefore the pull-up resistor may be omitted.

LE920 Hardware User Guide

12.4. Using the Temperature Monitor Function

12.4.1. Short Description

The Temperature Monitor is a function of the module that permits to control its internal temperature and if properly set (see the #TEMPMON command on AT Interface guide) it raises to High Logic level a GPIO when the maximum temperature is reached.

LED status

Device Status

Permanently off

Device off

Fast blinking

(Period 1s, Ton 0,5s)

Net search / Not registered / turning off

Slow blinking

(Period 3s, Ton 0,3s)

Registered full service

Permanently on

a call is active

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12.5. Indication of Network Service Availability

The STAT_LED pin status shows information on the network service availability and call status. In the LE920 modules, the STAT_LED usually needs an external transistor to drive an external LED. Because of the above, the status indicated in the following table is reversed with respect to the pin status:

Min

Typical

Max

Output voltage

1.75V

1.80V

1.85V

Output current

100mA

Output bypass capacitor

(Inside the module)

1μF

12.6. RTC Bypass

The VRTC pin brings out the Real Time Clock supply, which is separate from the rest of the digital part, allowing having only the RTC operating when all the other parts of the device are turned off.

If maintaining internal RTC block is needed, it recommended to connect a backup capacitor or a coin cell to this pin (valid range from 2.5V to 3.2V), otherwise, it can be left unconnected

Operating Modes:

1. LE920 has a valid VBAT supply, and the unit is turned ON – RTC block supply will be

generated from main VBAT supply, and the VRTC pin will output the VRTC supply, charging external coin cell or capacitor.

2. LE920 has no VBAT connected – The External coin cell or capacitor will maintain

VRTC supply, keeping the internal RTC unit block operational.

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NOTE:

NO devices may be powered from this pin.

12.7. VAUX Power Output

A regulated power supply output is provided in order to supply small devices from the module. This output is active when the module is ON and goes OFF when the module is shut down. The operating range characteristics of the supply are:

Operating Range – VAUX power supply

Min

Max

Units

Input Voltage range

1.7

Volt

AD conversion

- 8 bits

Resolution

< 6.6

13. ADC section

13.1. ADC Converter

13.1.1. Description

The on board ADCs are 8-bit converters. They are able to read a voltage level in the range of 0-2 volts applied on the ADC pin input and store and convert it into 8 bit word.

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The LE920 module provides 3 Analog to Digital Converters.

13.1.2. Using ADC Converter

An AT command is available to use the ADC function.

The command is AT#ADC=1,2. The read value is expressed in mV

Refer to SW User Guide or AT Commands Reference Guide for the full description of this function.

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14. Mounting the module on your board

14.1. General

The LE920 modules have been designed to be compliant with a standard lead-free SMT process.

14.2. Finishing & Dimensions

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14.3. Recommended foot print for the application

198 pads

Top View

In order to easily rework the LE920 it is suggested to consider that the application has a 1.5 mm placement inhibit area around the module.

It is also suggested, as a common rule for an SMT component, to avoid having a mechanical part of the application in direct contact with the module.

NOTE:

In the customer application, the region under WIRING INHIBIT (see figure above) must be clear from signal or ground paths.

14.4. Stencil

Stencil’s apertures layout can be the same as the recommended footprint (1:1). A suggested thickness of stencil foil is greater than 120 µm.

14.5. PCB Pad Design

Non solder mask defined (NSMD) type is recommended for the solder pads on the PCB.

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Finish

Layer thickness (um)

Properties

Electro-less Ni / Immersion Au

3 –7 / 0.05 – 0.15

good solder ability protection, high shear force values

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14.6. Recommendations for PCB Pad Dimensions (mm)

It is not recommended to place via or micro-via not covered by solder resist in an area of 0,3 mm around the pads unless it carries the same signal of the pad itself (see following figure).

Holes in pad are allowed only for blind holes and not for through holes.

Recommendations for PCB Pad Surfaces:

The PCB must be able to resist the higher temperatures which occur during the lead-free process. This issue should be discussed with the PCB-supplier. Generally, the wettability of tinlead solder paste on the described surface plating is better compared to lead-free solder paste.

Solder Paste

Lead free

Sn/Ag/Cu

14.7. Solder Paste

We recommend using only “no clean” solder paste in order to avoid the cleaning of the modules after assembly.

14.7.1. Solder Reflow

Recommended solder reflow profile:

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Profile Feature

Pb-Free Assembly

Average ramp-up rate (TL to TP)

3°C/second max

Preheat – Temperature Min (Tsmin) – Temperature Max (Tsmax) – Time (min to max) (ts)

150°C 200°C 60-180 seconds

Tsmax to TL – Ramp-up Rate

3°C/second max

Time maintained above: – Temperature (TL) – Time (tL)

217°C 60-150 seconds

Peak Temperature (Tp)

245 +0/-5°C

Time within 5°C of actual Peak Temperature (tp)

10-30 seconds Ramp-down Rate

6°C/second max.

Time 25°C to Peak Temperature

8 minutes max.

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NOTE:

All temperatures refer to topside of the package, measured on the package body surface.

WARNING:

The LE920 module withstands one reflow process only.

LE920 Hardware User Guide

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15. Application guide

15.1. Debug of the LE920 in production

To test and debug the mounting of LE920, we strongly recommend foreseeing test pads on the host PCB, in order to check the connection between the LE920 itself and the application and to test the performance of the module by connecting it with an external computer. Depending on the customer application, these pads include, but are not limited to the following signals:

 TXD

 RXD

 ON/OFF

 SHUTDOWN

 RESET

 GND

 VBATT

 TXD_AUX

 RXD_AUX

 USB_VBUS

 USB_D+

 USB_D-

In addition the below signal are also recommended (but not must)

 PWRMON

 STAT_LED

 SW_RDY

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15.2. Bypass capacitor on Power supplies

When a sudden voltage is asserted to or cut from the power supplies, the steep transition makes some reactions such as overshoot and undershoot.

This abrupt voltage transition can affect the device causing it to not work or make it malfunction.

Bypass capacitors are needed to alleviate this behavior. The behavior can be affected differently according to the various applications. Customers must pay special attention to this when they design their application board.

The length and width of the power lines need to be considered carefully and the capacitance of the capacitors need to be selected accordingly.

The capacitor will also prevent ripple of the power supplies and the switching noise caused in TDMA systems like GSM.

Especially, a suitable bypass capacitor must be mounted on the Vbatt & Vbatt_PA (Pads AP17,AP19,AR18,AS17,AS19,AT18,AU17,AU19) and USB_VBUS (Pad A18) lines in the application board.

The recommended values can be presented as:

 100uF for Vbatt

 4.7uF for USB_VBUS (including the 1uF capacitor inside the module).

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.

Product P/N

C1 range (nF)

LE920-EU/NA

100 nF

15.3. SIM interface

This section deals with the recommended schematics for the design of SIM interfaces on the application boards.

15.3.1. SIM schematic example

Figure 1 illustrates in particular how the application side should be designed, and what values the components should have.

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NOTE FOR R1:

The resistor value on SIMIO pulled up to SIMVCC should be defined accordingly in order to be compliant with 3GPP specification for USIM electrical testing.

LE920 contains an internal pull-up resistor of 20KΩ on SIMIO.

However, the un-mounted option in the application design can be recommended in order to tune R1 if necessary.

The following Table lists the values of C1 to be adopted with the LE920 product:

Refer to the following document for the detail:

 80000NT10026A - SIM Interface And ESD Protection Application Note Rev.2

SIMCLK1

SIMRST1

SIMVCC1

LE920-NA AUTO S module

SIMIN1

ESIM_RST

SIMIO1

GND

A10

B11

15.3.2. eSIM interface guidelines

NOTE:

eSIM feature available with LE920-NA AUTO S model only.

LE920-NA AUTO S model designed to operate either with internal build-in eSIM, external SIM card or with both options, switching SIM cards using following setups:

 For using internal eSIM configuration only, connect E8 pin “ESIM_RST” to B11

“SIMRST1”.

Connect B7 SIMIN1 to GND, leave all other SIM card ports disconnected:

LE920 Hardware User Guide

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Not mounted

B11

A10

SIMCLK1

SIMRST1

SIMVCC1

LE920-NA AUTO S module

SIMIN1

SIMIN

2 3 4

ESIM_RST

SIMIO1

External SIM card

SPDT switch 1

SPDT switch 2

SW1

SW2

8.2K

GND

200k

GND

100nF

33pF

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 For external SIM configuration only, leave E8 open (or set to GND) and follow 15.3.1

section guidelines.

 For configuration with both internal eSIM and external SIM cards use following

approach:

1) Both eSIM and external SIM share the same lines except SIMRST1 and SIMIN1

lines that should be switched between them, either electronically or manually. For SIMRST1 switching, it is mandatory to keep second output of SW1 in high Z state when connected to the first one, therefore analog relay (for example DG9431 Single SPDT Analog Switch) / mechanical relay / 3 state buffer with separate enable for each output is recommended.

2) Connect 200kΩ pulldown resistor (R2) to external SIM Reset line for keeping

external SIM in high Z state during internal eSIM use, whenever SIMRST1 signal routed to E8 ESIM_RST path. This method prevents interference between the SIM cards enabling only one of them by SW1 selection.

3) For SIMIN1 card detection mechanism, similar approach to SIMRST1

recommended. Manual selection with 0Ω resistors is another option.

NOTE FOR R1:

The resistor value on SIMIO pulled up to SIMVCC should be defined accordingly in order to be compliant with 3GPP specification.

LE920-NA AUTO S contains an internal pull-up resistor on SIMIO1.

However, the un-mounted option in the application design can be recommended in order to tune R1 if necessary.

Pad

Signal

I/O

Function

Contact

Air

All Pins

All

± 4KV

± 8KV

Antenna

AD1,AU9,S1

Antenna

Pads

Antenna pad

± 8KV

± 15KV

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15.4. EMC recommendations

All LE920 signals are provided with some EMC protection. Nevertheless the accepted level differs according to which pin. The characteristics are described in the following Table:

Appropriate series resistors must be considered to protect the input lines from overvoltage.

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15.5. Download and Debug Port

One of the following options should be chosen in the design of host system in order to download or upgrade the Telit software and debug LE920 when LE920 is already mounted on a host system.

Users who use both UART and USB interfaces to communicate with LE920

- Must implement a USB download method in a host system for upgrading LE920 when it is

mounted.

Users who use USB interface only to communicate with LE920

- Must arrange for a USB port in a host system for debugging or upgrading LE920 when it is

mounted.

Users who use UART interface only to communicate with LE920

LE920 Hardware User Guide

- Must arrange for a USB port in a host system for debugging or upgrading LE920 when

it is mounted.

Tray

in each

tray

inside each

envelope

inside each

carton box

Modules/tray

Description

modules/

tray

trays/

envelope

modules/

envelope

envelopes/

carton box

modules/

box

xE920

packaging

JEDEC Tray

5+ 1 empty

120 4 480

Qty

Minimum Order Quantity (MOQ)

120

Standard Packing Quantity (SPQ)

480

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16. Packing system

The Telit LE920 is packaged on trays. The tray is JEDEC compliant, injection molded antistatic Modified Polyphenylene ether (MPPO). It has good thermal characteristics and can withstand a the standard baking temperature up to 125°C, thereby avoiding handling the modules if baking is required. The trays are rigid, thus providing more mechanical protection against transport stress. Additionally they are re-usable and so environmentally sustainable.

There are 2 (two) antistatic rubber bands that enclose each envelope.

The carton box is rigid, thus offering mechanical protection. The carton box has one flap across the whole top surface. It is sealed with tape along the edges of the box.

Each tray contains 24 pieces as shown in the following picture:

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16.1. Tray Drawing

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16.2. Moisture Sensitivity

The LE920 is a Moisture Sensitive Device level 3, in accordance with standard IPC/JEDEC JSTD-020. Observe all of the requirements for using this kind of components.

Calculated shelf life in sealed bag: 4 months at <40°C and <90% relative humidity (RH).

LE920 Hardware User Guide

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17. Safety Recommendations

READ CAREFULLY

Be sure that the use of this product is allowed in your country and in the environment required. The use of this product may be dangerous and must 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 regulations and the specific environment regulations.

Do not disassemble the product; any mark of tampering will compromise the warranty validity.

LE920 Hardware User Guide

We recommend following the instructions of the hardware user guides for correct wiring of the product. The product must be supplied with a stabilized voltage source and the wiring conform to the security and fire prevention regulations.

The product must be handled with care, avoiding any contact with the pins because electrostatic discharges may damage the product itself. The same caution must be taken for the SIM, checking carefully the instructions 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 must be taken of the external components of the module, as well as of any project or installation issue, because of the risk of disturbing the GSM network or external devices or having any impact on safety. Should there be any doubt, please refer to the technical documentation and the regulations in force.

Every module must be equipped with a proper antenna with the specified characteristics. The antenna must be installed with care in order to avoid any interference with other electronic devices and must be installed with the guarantee of a minimum 20 cm distance from a human body. In case this requirement cannot be satisfied, the system integrator must assess the final product against the SAR regulation.

The European Community provides some Directives for electronic equipment introduced on the market. All 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

Revision

Date

Changes

0-draft1

2012-10-03

First issue

0-draft2

2012-12-11

- Remove SIM2 interface

- Remove external GPS LNA support

0-draft3

2013-03-12

Updated pin-out

0-draft4

2013-05-21

- Update DVI

- Adding Current consumption

- Adding SHDN_N section

- Update Mechanical drawings

0-draft5

2013-10-08

- Remove VRTC support

- Section 2.2, update tolerance value

- Section 3.1, remove VRTC and 2nd analog audio signals

- Section 4.2, update PWRMON turn on to 100mSec

- Section 4.3.2, update Hold Time min to 2.5 seconds

- Section 4.3.3, update RESET control timing details

- Section 5.1, update table

- Section 6.5, update insertion Loss value

- Section 8, remove USB Low speed support

- Section 10, adding Analog Audio support.

- Section 14.4, update table

2014-02-04

Initial ‘official’ Release

- Added LE920-NV support

- Added VRTC support

- Added Section 2.6, sensitivity

- Section 8, added note

- Section 13.3, update figure

- Section 14.3, update description

2014-04-02

General editorial update

- Update 8, Firmware update

- Update 14.5, Firmware update

2014-09-26

- Removed LE920-NV support

- Section 8, update USB_VBUS notes

- Section 15, update packing drawing and text

2015-03-19

- Add Section 10, Peripheral Ports

- Section 6.4, added note for diversity antenna connection

- Section 5.1, added additional CFUN=5 measurements

- Section 12, remove ‘high voltage tolerate’

- Section 3.1, Update pinout

- Section 12.6 update

- Section 15.3 update

2015-04-27

- Section 3.1, correct SPI_CS LGA pad

- Section 3.1.1 update figure

- Section 10.1, correct SPI_CS LGA pad

- Added differences NAG and NA (removing name NAA)

- Section 2.5, changed to 3 discrete figures

18. Document History

LE920 Hardware User Guide

1vv0301026 Rev.8 2015-01-03

2015-06-25

- Section 3.1 correct pad F19 Function description

2015-09-21

- APPLICABILITY TABLE 1 – adding LE920-CN, LE920-

NA AUTO S models. Added cs numbers per model.

- Section 1.4 Document Organization links fixed.

- Section 2.5 - Added cs numbers per model.

- Added section 2.5.4 – LE920-CN model bands.

- LE920-NA AUTO S added to section 2.5.3

- Section 2.6 - added sensitivity levels for TD-SCDMA & 4G

TDD.

- Section 3.1, 3.1.1, 15.4 – added ESIM_RST signal for LE920-NA AUTO S model.

- Section 6.5 modified according to GPS active / passive

antenna configuration changes.

- Added section 15.3.2 – eSim schematic example.

- Section 10.4 LE920-EUA changed to LE920-EU

2016-02-02

- Section 3.1, 3.11 – Pad V2 GPS_LNA_EN functionality

declared to customer. Pads G2, J2, L2, F3, H3, K3, E4, and AN14 must be routed to TP for Telit debugging purpose.

- Section 2.5.3 - Changing B17 support to B12.

- Sections 6.1 , 6.4 – Adding B12 support to GSM/WCDMA/LTE & Diversity Antenna requirements.

- Section 2.5.2 , 2.5.3 channels corrected for WCDMA B4.

- Section 5.2.1.3 – Battery recommendations updated.

- Section 15.1 – Recommended signals for debug updated.

- Section 15.2 – Recommended USB_VBUS decupling

capacitor value updated.

- Section 15.4 – EMC recommendations updated.

2016-03-29

- Adding section 2.7 Conformity assessment issues

LE920 Hardware User Guide

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Telit Communications S p A LE920NA1 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual