Telit Communications S.p.A. DE921 User Manuals

Table of Contents

• Introduction

  8
• Scope

  8
• Audience

  8
• Contact Information, Support

  8
• Document Organization

  9
• Text Conventions

  10
• Related Documents

  10
• General Product Description

  11
• Overview

  11
• Product Specifications

  12
• RoHS Compliance

  13
• DE921 Module Connections

  14
• Pin-Out

  14
• BGA Pads Layout

  19
• Hardware Commands

  20
• Turning on the DE921 module

  20
• Initialization and Activation State

  20
• Turning off the DE921 module

  22
• Shutdown by Software Command

  23
• Hardware Shutdown

  23
• Hardware Reset

  24
• Hardware Reset

  24
• Summary of Turning ON and OFF the Module

  25
• Power Supply

  26
• Power Supply Requirements

  26
• General Design Rules

  28
• Electrical Design Guidelines

  28
• + 5V Input Source Power Supply Design Guidelines

  28
• +12V Input Source Power Supply Design Guidelines

  29
• Battery Source Power Supply Design Guidelines

  30
• Thermal Design Guidelines

  31
• Power Supply PCB layout Guidelines

  32
• Antenna

  34
• CDMA Antenna Requirements

  34
• CDMA antenna – PCB line Guidelines

  35
• PCB Guidelines in case of FCC certification

  36
• CDMA Antenna – Installation Guidelines

  38
• GNSS Antenna Requirements

  39
• Combined GNSS Antenna

  39
• Linear and Patch GNSS Antenna

  39
• The Design Considerations to enhanced GNSS performance

  39
• GNSS Antenna – PCB Line Guidelines

  42
• GNSS Antenna – Installation Guidelines

  42
• USB Port

  43
• Serial Port

  44
• Modem Serial Port 1

  45
• Modem Serial Port 2

  46
• RS232 Level Translation

  46
• Audio Section Overview

  49
• Electrical Characteristics

  49
• CODEC Example

  49
• 10. General Purpose I/O

  50
• Logic Level Specification

  51
• Using a GPIO Pad as Input

  51
• Using a GPIO Pad as Output

  52
• Using the Temperature Monitor Function

  52
• Short Description

  52
• Indication of Network Service Availability

  53
• VCOIN

  54
• VCC_1V8 Power Output

  55
• 11. ADC section

  56
• ADC Converter

  56
• Description

  56
• Using ADC Converter

  56
• 12. Test Point

  57
• 13. Mounting the Module on your Board

  58
• General

  58
• Module Finishing & Dimensions

  58
• Recommended foot print for the application

  59
• PCB Pad Design

  59
• Recommendations for PCB Pad Dimensions (mm)

  60
• Solder Paste

  61
• Solder Reflow

  61
• 14. Packing System

  63
• Reel

  63
• Carrier Tape Detail

  63
• Reel Detail

  63
• Packaging Detail

  63
• Moisture Sensibility

  64
• 15. Application Design Guide

  65
• Download and Debug Port

  65
• 16. Certifications and Conformity

  66
• 17. Safety Recommendations

  69
• 18. Document History

  70