Telit Communications S p A GE865C Quadband GSM/ GPRS Module User Manual GE865 Harware User Guide

Telit Communications S.p.A. Quadband GSM/ GPRS Module GE865 Harware User Guide

UserManual.wiki >

Telit Communications S p A >

GE865C User Manual HTML Version

User Manual

GE865 Hardware User Guide

1vv0300799 Rev.11 13-07-2010

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

APPLICABILITY TABLE

PRODUCT

GE865

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

DISCLAIMER

The information contained in this document is the proprietary information of Telit

Communications S.p.A. and

any disclosure to persons other than the officers, employees, agents or subcontractors

of the owner or licensee of this document, without the prior written consent of Telit, is

strictly prohibited.

Telit makes every effort to ensure the quality of the information it makes available.

Notwithstanding the foregoing, Telit does not make any warranty as to the information

contained herein, and does not accept any liability for any injury, loss or damage of any

kind incurred by use of or reliance upon the information.

Telit disclaims any and all responsibility for the application of the devices characterized

in this document, and notes that the application of the device must comply with the

safety standards of the applicable country, and where applicable, with the relevant

wiring rules.

Telit reserves the right to make modifications, additions and deletions to this document

due to typographical errors, inaccurate information, or improvements to programs

and/or equipment at any time and without notice. Such changes will, nevertheless be

incorporated into new editions of this application note.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

Contents

APPLICABILITY TABLE ....................................................................................................................................................... 2

1 INTRODUCTION ...................................................................................................................................................... 6

1.1 SCOPE .............................................................................................................................................................................. 6

1.2 AUDIENCE ......................................................................................................................................................................... 6

1.3 CONTACT INFORMATION, SUPPORT .................................................................................................................................... 6

1.4 DOCUMENT ORGANIZATION ................................................................................................................................................ 7

1.5 TEXT CONVENTIONS........................................................................................................................................................... 8

1.6 RELATED DOCUMENTS ...................................................................................................................................................... 8

1.7 DOCUMENT HISTORY ......................................................................................................................................................... 9

2 OVERVIEW ............................................................................................................................................................. 10

3 GE865 MECHANICAL DIMENSIONS .................................................................................................................. 12

4 GE865 MODULE CONNECTIONS ........................................................................................................................ 13

4.1 PIN-OUT ....................................................................................................................................................................... 13

4.1.1 BGA Balls Layout

................................................................................................................................................. 16

5 HARDWARE COMMANDS .................................................................................................................................... 17

5.1 TURNING ON THE GE865 ................................................................................................................................................ 17

5.2 TURNING OFF THE GE865 .............................................................................................................................................. 22

5.3 RESETTING THE GE865 ................................................................................................................................................... 25

5.3.1 Hardware Unconditional restart

....................................................................................................................... 25

6 POWER SUPPLY ................................................................................................................................................... 28

6.1 POWER SUPPLY REQUIREMENTS ...................................................................................................................................... 28

6.2 POWER CONSUMPTION .................................................................................................................................................... 29

6.3 GENERAL DESIGN RULES ................................................................................................................................................ 30

6.3.1 Electrical Design Guidelines

.............................................................................................................................. 30

6.3.2 Thermal Design Guidelines

............................................................................................................................... 34

6.3.3 Power Supply PCB layout Guidelines

............................................................................................................... 36

7 ANTENNA .............................................................................................................................................................. 37

7.1 GSM ANTENNA REQUIREMENTS ...................................................................................................................................... 37

7.2 GSM ANTENNA - PCB LINE GUIDELINES ......................................................................................................................... 38

7.3 GSM ANTENNA - INSTALLATION GUIDELINES ................................................................................................................... 39

8 LOGIC LEVEL SPECIFICATIONS ......................................................................................................................... 40

8.1 RESET SIGNAL ................................................................................................................................................................. 41

9 SERIAL PORTS ..................................................................................................................................................... 42

9.1 MODEM SERIAL PORT ................................................................................................................................................ 42

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

9.2 RS232 LEVEL TRANSLATION ............................................................................................................................................ 44

9.3 5V UART LEVEL TRANSLATION ........................................................................................................................................ 48

10 AUDIO SECTION OVERVIEW ........................................................................................................................... 50

10.1 ELECTRICAL CHARACTERISTICS ..................................................................................................................................... 51

10.1.1 Input Lines

......................................................................................................................................................... 51

10.1.2 Output Lines

....................................................................................................................................................... 52

11 GENERAL PURPOSE I/O ................................................................................................................................. 53

11.1 GPIO LOGIC LEVELS ...................................................................................................................................................... 54

11.2 USING A GPIO PAD AS INPUT ...................................................................................................................................... 56

11.3 USING A GPIO PAD AS OUTPUT ................................................................................................................................... 56

11.4 USING THE RF TRANSMISSION CONTROL GPIO4 ............................................................................................................ 56

11.5 USING THE RFTXMON OUTPUT GPIO5 ........................................................................................................................ 57

11.6 USING THE ALARM OUTPUT GPIO6 ................................................................................................................................ 57

11.7 USING THE BUZZER OUTPUT GPIO7 .............................................................................................................................. 58

11.8 MAGNETIC BUZZER CONCEPTS ...................................................................................................................................... 59

11.8.1 Short Description

.............................................................................................................................................. 59

11.8.2 Frequency Behaviour

........................................................................................................................................ 59

11.8.3 Power Supply Influence

................................................................................................................................... 60

11.8.4 Working Current Influence

.............................................................................................................................. 60

11.9 INDICATION OF NETWORK SERVICE AVAILABILITY ............................................................................................................. 61

11.10 RTC BYPASS OUT ........................................................................................................................................................ 63

11.11 EXTERNAL SIM HOLDER IMPLEMENTATION .................................................................................................................. 63

12 DAC AND ADC SECTION ................................................................................................................................. 64

12.1 DAC CONVERTER .......................................................................................................................................................... 64

12.1.1 Description

......................................................................................................................................................... 64

12.1.2 Enabling DAC

..................................................................................................................................................... 65

12.1.3 Low Pass Filter Example

................................................................................................................................. 65

12.2 ADC CONVERTER .......................................................................................................................................................... 66

12.2.1 Description

......................................................................................................................................................... 66

12.2.2 Using ADC Converter

........................................................................................................................................ 66

13 MOUNTING THE GE865 ON YOUR BOARD .................................................................................................... 67

13.1 GENERAL ...................................................................................................................................................................... 67

13.2 MODULE FINISHING & DIMENSIONS ................................................................................................................................ 67

13.3 RECOMMENDED FOOT PRINT FOR THE APPLICATION ........................................................................................................ 68

13.4 DEBUG OF THE GE865 IN PRODUCTION .......................................................................................................................... 69

13.5 STENCIL ........................................................................................................................................................................ 69

13.6 PCB PAD DESIGN .......................................................................................................................................................... 70

13.7 SOLDER PASTE .............................................................................................................................................................. 72

13.7.1 GE865 Solder reflow

......................................................................................................................................... 73

14 PACKING SYSTEM ........................................................................................................................................... 76

14.1 MOISTURE SENSIBILITY .................................................................................................................................................. 77

15 CONFORMITY ASSESSMENT ISSUES............................................................................................................ 78

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

16 SAFETY RECOMMANDATIONS ....................................................................................................................... 80

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

1 Introduction

1.1 Scope

The aim of this document is the description of some hardware solutions useful for

developing a product with the Telit GE865 module.

1.2 Audience

This document is intended for Telit customers, who are integrators, about to implement

their applications using our GE865 modules.

1.3 Contact Information, Support

For general contact, technical support, to report documentation errors and to order

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

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.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

1.4 Document Organization

This document contains the following chapters:

provides a scope for this document, target audience, contact

and support information, and text conventions.

provides an overview of the document.

Chapter 4 Module Connections out configuration and layout.

How to operate on the module via hardware.

Power supply requirements and general design rules.

The antenna connection and board layout design are the most

important parts in the full product design.

Specific values adopted in the implementation of

logic levels for this module.

The serial port on the Telit GE865 is the core of the interface

between the module and OEM hardware

Refers to the audio blocks of the Base Band Chip

of the GE865 Telit Modules.

How the general purpose I/O pads can be

configured.

Deals with these two kind of converters.

E865 Recommendations and

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

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.

1.6 Related Documents

Telit's GSM/GPRS Family Software User Guide, 1vv0300784

Audio settings application note , 80000NT10007a

Digital Voice Interface Application Note, 80000NT10004a

GE865 Product description,

SIM Holder Design Guides, 80000NT10001a

AT Commands Reference Guide, 80000ST10025a

Telit EVK2 User Guide, 1vv0300704

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

1.7 Document History

ISSUE#0

2009-01-26

First ISSUE# 0 - DRAFT

ISSUE#1

2009-02-15

Updated current consumptions table

ISSUE#2

2009-02-15

Updated Pinout description

ISSUE#3

2009-03-18

Updated mechanical dimensions (balls spacing),

charger description removed,

Added better explanation of pin H5 (RF) and H1 (service)

ISSUE#4

2009-04-02

Updated VBATT supply Range, DAC schematic, Conformity assessment

ISSUE#5

03/06/2009

Updated section 13 (FCC Conformity assessment)

ISSUE#6

04/06/2009

Updated section 13 (FCC Conformity assessment)

ISSUE#7

2009-05-26

Applied new layout + minor editing

Edited PCB pad design par.13.1.6

ISSUE#8

2009-06-18

Updated all schematic drawings

Updated Chapter 10 Audio Section

Substituted GE865-QUAD with GE865

Corrected GE864-QUAD/PY with GE865

Updated Overview section

ISSUE#9

2009-07-27

Changed par. 5.1 Turning ON and par. 6.1 Power supply Requirements

Changed par. 13.3 and par.15 Conformity Assessment Issues

ISSUE#10

2009-09-22

Added DVI pins description

Updated table of power consumptions.

Added note on chapters 5.1, 5.2, 9.3

Corrected chapter 1.1

ISSUE#11

2010-07-12

Updated logic levels specification

Added NOTE on ON_OFF procedure, serial port , GPIO section

Corrected note on RESET section

Updated Current Consumptions

Updated flow charts for ON OFF and Reset

Updated name for Auxiliary UART port

Updated Chapter 7

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

2 Overview

The aim of this document is the description of some hardware solutions useful for

developing a product with the Telit GE865 module.

In this document all the basic functions of a mobile phone will be taken into account;

for each one of them a proper hardware solution will be suggested and eventually the

wrong solutions and common errors to be avoided will be evidenced. Obviously this

document cannot embrace the whole hardware solutions and products that may be

designed. The wrong solutions to be avoided shall be considered as mandatory, while

the suggested hardware configurations shall not be considered mandatory, instead the

information given shall be used as a guide and a starting point for properly developing

your product with the Telit GE865 module. For further hardware details that may not be

explained in this document refer to the Telit GE865 Product Description document

where all the hardware information is reported.

NOTICE:

(EN) The integration of the GSM/GPRS GE865 cellular module within user application

shall be done according to the design rules described in this manual.

GE865

(DE) Die Integration des GE865 GSM/GPRS Mobilfunk-Moduls in ein Gerät muß gemäß

der in diesem Dokument beschriebenen Kunstruktionsregeln erfolgen.

(SL) Integracija GSM/GPRS GE865 modula v u

projektna navodila, opisana v tem piročniku.

(SP) La utilización del modulo GSM/GPRS GE865 debe ser conforme a los usos para los

cuales ha sido deseñado descritos en este manual del usuario.

u module cellulaire GSM/GPRS GE865

(HE)

GE865-QUAD

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

The information presented in this document is believed to be accurate and reliable.

However, no responsibility is assumed by Telit Communications S.p.A. for its use, nor

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

Communications S.p.A. other than for circuitry embodied in Telit products. This

document is subject to change without notice.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

3 GE865 Mechanical Dimensions

The GE865 overall dimensions are:

Length: 22 mm

Width: 22 mm

Thickness: 3.0 mm

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

4 GE865 module connections

4.1 PIN-OUT

Ball

Signal

I/O

Function

Note

Type

Audio

EAR-

Earphone signal output, phase -

Audio

EAR+

Earphone signal output, phase +

Audio

MIC+

Mic.signal input; phase+

Audio

MIC-

Mic.signal input; phase-

Audio

SIM card interface

SIMCLK

External SIM signal Clock

1,8 / 3V

SIMRST

External SIM signal Reset

1,8 / 3V

SIMIO

I/O

External SIM signal Data I/O

4.7K Pull up

1,8 / 3V

SIMIN

External SIM signal Presence (active low)

1,8 / 3V

SIMVCC

External SIM signal Power supply for the SIM

1,8 / 3V

Trace

TX_AUX

Auxiliary UART (TX Data to DTE)

CMOS 2.8V

RX_AUX

Auxiliary UART (RX Data from DTE)

CMOS 2.8V

Prog. / Data + HW Flow Control

C103/TXD

Serial data input (TXD) from DTE

CMOS 2.8V

C104/RXD

Serial data output to DTE

CMOS 2.8V

C108/DTR

Input for Data terminal ready signal (DTR)

from DTE

CMOS 2.8V

C105/RTS

Input for Request to send signal (RTS) from

DTE

CMOS 2.8V

C106/CTS

Output for Clear to send signal (CTS) to DTE

CMOS 2.8V

C109/DCD

Output for Data carrier detect signal (DCD) to

DTE

CMOS 2.8V

C107/DSR

Output for Data set ready signal (DSR) to DTE

CMOS 2.8V

C125/RING

Output for Ring indicator signal (RI) to DTE

CMOS 2.8V

DAC and ADC

DAC_OUT

Digital/Analog converter output

D/A

ADC_IN1

Analog/Digital converter input

A/D

ADC_IN2

Analog/Digital converter input

A/D

Miscellaneous Functions

RESET*

Reset input

VRTC

VRTC Backup capacitor

Power

STAT_LED

Status indicator led

CMOS 1.8V

ON_OFF*

Input command for switching power ON or OFF

(toggle command).

47K Pull Up

Pull up to VRTC

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

Ball

Signal

I/O

Function

Note

Type

PWRMON

Power ON Monitor

CMOS 2.8V

Antenna

Antenna output 50 Ω

Service

Service pin can be used to upgrade the

module from ASC1 as a alternative to default

upgrading procedure using ASC0

CMOS 2.8V

GPIO

GPIO_01 / DVI_WA0

I/O

GPIO01 Configurable GPIO / Digital Audio

Interface (WA0)

CMOS 2.8V

GPIO_02 / JDR /

DVI_RX

I/O

GPIO02 I/O pin / Jammer Detect Report /

Digital Audio Interface (RX)

CMOS 2.8V

GPIO_03 / DVI_TX

I/O

GPIO03 GPIO I/O pin // Digital Audio Interface

(TX)

CMOS 2.8V

GPIO_04 / TX_DISAB

I/O

GPIO04 Configurable GPIO / TX Disable input

CMOS 2.8V

GPIO_05 / RFTXMON

I/O

GPIO05 Configurable GPIO / Transmitter ON

monitor

CMOS 2.8V

GPIO_06 / ALARM

I/O

GPIO06 Configurable GPIO / ALARM

CMOS 2.8V

GPIO_07 / BUZZER

I/O

GPIO07 Configurable GPIO / Buzzer

CMOS 2.8V

GPIO_08 / DVI_CLK

I/O

GPIO08 Configurable GPIO / Digital Audio

Interface (CLK)

CMOS 2.8V

GPIO_09

I/O

GPIO09

4.7 K Pull Up

Open Drain

GPIO_10

I/O

GPIO10

4.7 K Pull Up

Open Drain

Power Supply

VBATT

Main power supply (Baseband)

Power

VBATT_PA

Main power supply (Radio PA)

Power

VBATT_PA

Main power supply (Radio PA)

Power

GND

Ground

Power

GND

Ground

Power

GND

Ground

Power

GND

Ground

Power

GND

Ground

Power

GND

Ground

Power

GND

Ground

Power

GND

Ground

Power

GND

Ground

Power

GND

Ground

Power

RESERVED

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

Ball

Signal

I/O

Function

Note

Type

WARNING:

Reserved pins must not be connected.

NOTE:

If not used, almost all pins should be left disconnected. The only exceptions are the

following pins:

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

signal

F1,F2,F3

VBATT & VBATT_PA

G1, C2, C7, E5, E7, G5,

G4, G3, H3, H6

GND

ON/OFF*

TXD

RESET*

RXD

RTS

TXD_AUX

RXD_AUX

Service

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

4.1.1 BGA Balls Layout

TOP VIEW

C105 / RTS

ON_OFF

RESET*

TX_AUX

RX_AUX

VBATT

GND

SERVICE

C106/CTS

C107/DSR

GND

GPIO_02 /

DVI_RX

PWRMON

VBATT_PA

GPIO_05

VRTC

C103_TXD

C108/DTR

GPIO_01 /

DVI_WA0

GPIO_10

VBATT_PA

GND

C104/RXD

C125/RING

GPIO_08 /

DVI_CLK

GPIO_03 /

DVI_TX

GPIO_09

GND

SIMCLK

C109/DCD

GND

ADC1

GND

ANT

SIMIO

ADC2

GPIO_07

GND

SIMVCC

SIMIN

GND

DAC

GPIO_04

SIMRST

MIC+

MIC-

EAR+

EAR-

STATLED

GPIO_06

LEGENDA:

NOTE:

The pin defined as H4 has to be considered RESERVED and not connected on any pin in

the application. The related area on the application has to be kept empty.

AUDIO

SIM CARD

ANTENNA

UARTS

DAC and ADC

MISCELLANEOUS

GPIO

POWER SUPPLY VBATT

POWER SUPPLY GND

RESERVED

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

5 Hardware Commands

5.1 Turning ON the GE865

To turn on the GE865 the pad ON# must be tied low for at least 1 second and then

released.

When the power supply voltage is lower than 3.4V the pad ON# must be tied low at least

3 seconds.

The maximum current that can be drained from the ON# pad is 0,1 mA.

A simple circuit to do it is:

NOTE:

Don't use any pull up resistor on the ON# line, it is internally pulled up. Using pull up

resistor may bring to latch up problems on the GE865 power regulator and improper

power on/off of the module. The line ON# must be connected only in open collector

configuration.

ON#

Power ON impulse

GND

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

NOTE:

In this document all the lines that are inverted, hence have active low signals are

labelled

TIP:

To check if the device has powered on, the hardware line PWRMON should be

monitored. After 900ms the line raised up the device could be considered powered on.

NOTE:

It is mandatory to avoid sending data to the serial ports during the first 200mS of the

module startup.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

A flow chart showing the proper turn on procedure is displayed below:

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 GE865 when the module is powered

off or during an ON/OFF transition.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

A flow chart showing the AT command managing procedure is displayed below:

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

For example:

1- Let's assume you need to drive the ON# pad with a totem pole output of a +3/5 V

microcontroller (uP_OUT1):

2- Let's assume you need to drive the ON# pad directly with an ON/OFF button:

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

5.2 Turning OFF the GE865

Turning off of the device can be done in two ways:

via AT command (see GE865 Software User Guide, AT#SHDN)

by tying low pin ON#

Either ways, the device issues a detach request to network informing that the device will not be

reachable any more.

To turn OFF the GE865 the pad ON# must be tied low for at least 2 seconds and then released. A Pulse

duration less than 2 seconds should also start the power off procedure, but this is not guaranteed.

The same circuitry and timing for the power on must be used.

The device shuts down after the release of the ON# pad.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

The following flow chart shows the proper turnoff procedure:

TIP:

To check if the device has been powered off, the hardware line PWRMON must be

monitored. The device is powered off when PWRMON goes low.

NOTE:

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

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 GE865 when the module is powered

off or during an ON/OFF transition.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

5.3 Resetting the GE865

5.3.1 Hardware Unconditional restart

WARNING:

The hardware unconditional Restart must not be used during normal operation of the

device since it does not detach the device from the network. It shall be kept as an

emergency exit procedure to be done in the rare case that the device gets stacked

waiting for some network or SIM responses.

To unconditionally reboot the GE865, the pad RESET# must be tied low for at least 200 milliseconds

and then released.

The maximum current that can be drained from the RESET# pad is 0,15 mA.

NOTE:

Do not use any pull up resistor on the RESET* line nor any totem pole digital output.

Using pull up resistor may bring to latch up problems on the GE865 power regulator

and improper functioning of the module. The line RESET* must be connected only in

open collector configuration.

TIP:

The unconditional hardware restart must always be implemented on the boards and

the software must use it as an emergency exit procedure.

A simple circuit to do it is:

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

In the following flow chart is detailed the proper restart procedure:

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 GE865 when the module is powered

off or during an ON/OFF transition.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

For example:

1- Let us assume you need to drive the RESET# pad with a totem pole output of a +3/5

V microcontroller (uP_OUT2):

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

6 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 product overall performances, hence read

carefully the requirements and the guidelines that will follow for a proper design.

6.1 Power Supply Requirements

The external power supply must be connected to VBATT & VBATT_PA signals and must

fulfill the following requirements:

POWER SUPPLY

Nominal Supply Voltage

3.8 V

Normal Operating Voltage Range

3.4 V÷ 4.20 V

Extended Operating Voltage Range

3.22 V÷ 4.50 V

NOTE:

The Operating Voltage Range MUST never be exceeded; care must be taken in order to

fulfil min/max voltage requirement.

NOTE:

Overshoot voltage (regarding MAX Extended Operating Voltage) and drop in voltage

(regarding MIN Extended Operating Voltage) MUST never be exceeded;

and application of the HW User guide suggestions.

NOTE:

When the power supply voltage is lower than 3.4V, to turn ON the module, the pad ON#

must be tied low for at least 3 seconds. See para 5.1.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

6.2 Power Consumption

The GE865 power consumptions are:

GE865

Mode

Average

(mA)

Mode description

SWITCHED OFF

Module supplied but Switched Off

Switched Off

<62uA

IDLE mode

AT+CFUN=1

16,0

Normal mode: full functionality of the module

AT+CFUN=4

16,0

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

AT+CFUN=0 or =5

3,9

Paging Multiframe 2

2,5

Paging Multiframe 3

2,4

Paging Multiframe 4

1,5

Paging Multiframe 9

CSD TX and RX mode

GSM VOICE CALL

GSM900 CSD PL5

240

DCS1800 CSD PL0

175

GPRS (class 1) 1TX + 1RX

GPRS Sending data mode

GSM900 PL5

225

DCS1800 PL0

160

GPRS (class 10) 2TX + 3RX

GPRS Sending data mode

GSM900 PL5

420

DCS1800 PL0

290

The GSM system is made in a way that the RF transmission is not continuous, else it is

packed into bursts at a base frequency of about 216 Hz, and the relative current peaks

can be as high as about 2A. Therefore the power supply has to be designed in order to

withstand with 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 and the supply; this will reflect on all the audio paths producing an audible

annoying noise at 216 Hz; if the voltage drop during the peak current absorption is too

much, then the device may even shutdown as a consequence of the supply voltage drop.

NOTE:

The electrical design for the Power supply should be made ensuring it will be capable

of a peak current output of at least 2 A.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

6.3 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.

6.3.1 Electrical Design Guidelines

The electrical design of the power supply depends strongly from 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

6.3.1.1 + 5V input Source Power Supply Design Guidelines

The desired output for the power supply is 3.8V, hence there's 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 suited because of the low drop out requirements.

When using a linear regulator, a proper heat sink shall 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 the GE865, a 100μF tantalum capacitor is usually

suited.

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

is rated at least 10V.

A protection diode should be inserted close to the power input, in order to save the

GE865 from power polarity inversion.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

An example of linear regulator with 5V input is:

6.3.1.2 + 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 not suited and

shall not be used. A switching power supply will be preferable because of its better

efficiency especially with the 2A peak current load represented by the GE865.

When using a switching regulator, a 500kHz 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

interferences.

For car PB battery the input voltage can rise up to 15,8V and this should 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 suited.

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

is rated at least 10V.

For Car applications a spike protection diode should be inserted close to the power

input, in order to clean the supply from spikes.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

A protection diode should be inserted close to the power input, in order to save the

GE865 from power polarity inversion. This can be the same diode as for spike

protection.

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

parts):

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

6.3.1.3 Battery Source Power Supply Design Guidelines

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

allowed is 4.2V, hence a single 3.7V Li-Ion cell battery type is suited for supplying the

power to the Telit GE865 module.

WARNING:

The three cells Ni/Cd or Ni/MH 3,6 V Nom. battery types or 4V PB types

MUST NOT BE

USED DIRECTLY

since their maximum voltage can rise over the absolute maximum

voltage for the GE865 and damage it.

NOTE:

DON'T USE any Ni-Cd, Ni-MH, and Pb battery types directly connected with GE865.

Their use can lead to overvoltage on the GE865 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 suited.

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

A protection diode should be inserted close to the power input, in order to save the

GE865 from power polarity inversion. Otherwise the battery connector should be done

in a way to avoid polarity inversions when connecting the battery.

The battery capacity must be at least 500mAh in order to withstand the current peaks

of 2A; the suggested capacity is from 500mAh to 1000mAh.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

6.3.2 Thermal Design Guidelines

The thermal design for the power supply heat sink should be done with the following

specifications:

Average current consumption during transmission @ max PWR level:

500mA

Average current consumption during transmission @ min PWR level:

150mA

Average current during Power Saving (CFUN=5) :

2,4mA

Average current during idle (Power Saving disabled):

24mA

NOTE:

The average consumption during transmissions depends on the power level at which

the device is requested to transmit by the network. The average current consumption

hence varies significantly.

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 current significantly only during calls.

If we assume that the device stays into transmission for short periods of time (let's say

few minutes) and then remains for a quite long time in idle (let's say one hour), then the

power supply has always the time to cool down between the calls and the heat sink

could be smaller than the calculated one for 500mA maximum RMS current, or even

could be the simple chip package (no heat sink).

Moreover in the 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 the 500mA, being usually around 150mA.

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 GE865, you can consider it to be during transmission 1W

max during CSD/VOICE calls and 2W max during class10 GPRS upload.

This generated heat will be mostly conducted to the ground plane under the GE865; you

must ensure that your application can dissipate it.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

6.3.3 Power Supply PCB layout Guidelines

As seen on the electrical design guidelines the power supply shall 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 GE865 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 provided the PCB trace from the capacitor to the GE865 is

wide enough to ensure a dropless 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 when the 2A current peaks are absorbed.

Note that this is not made in order 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, 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 doesn't have audio interface but only uses the

data feature of the Telit GE865, then this noise is not so disturbing and power supply

layout design can be more forgiving.

The PCB traces to the GE865 and the Bypass capacitor must be wide enough to ensure

no significant voltage drops occur when the 2A current peaks are absorbed. This is for

the same reason as previous point. 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 (100-500 kHz usually).

The use of a good common ground plane is suggested.

The placement of the power supply on the board should be done in such a way to

guarantee that the high current return paths in the ground plane are not overlapped to

any noise sensitive circuitry as the microphone amplifier/buffer or earphone amplifier.

The power supply input cables should be kept separate from noise sensitive lines such

as microphone/earphone cables.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

7 Antenna

The antenna connection and board layout design are the most important aspect in the

full product design as they strongly affect the product overall performances, hence

read carefully and follow the requirements and the guidelines for a proper design.

7.1 GSM Antenna Requirements

As suggested on the Product Description the antenna and antenna transmission line on

PCB for a Telit GE865 device shall fulfil the following requirements:

ANTENNA REQUIREMENTS

Frequency range

Depending by frequency band(s) provided by the

network operator, the customer shall use the most

suitable antenna for that/those band(s)

Bandwidth

70 MHz in GSM850, 80 MHz in GSM900, 170 MHz in

DCS & 140 MHz PCS band

Gain

1.4dBi @900 and 3dBi @1800

1.4dBi @850 and 3dBi @1900

Impedance

50Ω

Input power

> 2 W

VSWR absolute max

≤ 10:1 (limit to avoid permanent damage)

VSWR recommended

≤ 2:1 (limit to fulfil all regulatory requirements)

When using the GE865, since there's no antenna connector on the module, the antenna

must be connected to the GE865 antenna pad (BGA Ball H5) by means of a transmission

line implemented on the PCB.

In the case the antenna is not directly connected at the antenna pad of the GE865, then

a PCB line is needed in order to connect with it or with its connector.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

This transmission line shall fulfill the following requirements:

ANTENNA LINE ON PCB REQUIREMENTS

Characteristic Impedance

50Ω

Max Attenuation

0,3 dB

Coupling with other signals shall be avoided

Cold End (Ground Plane) of antenna shall be equipotential to

the GE865 ground pins

Furthermore if the device is developed for the US market and/or Canada market, it

shall comply with the FCC and/or IC approval requirements:

This device is to be used only for mobile and fixed application. In order to re-use the

Telit FCC/IC approvals 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. If antenna is

installed with a separation distance of less than 20 cm from all persons or is co-located

or operating in conjunction with any other antenna or transmitter then additional

FCC/IC testing may be required. End-Users must be provided with transmitter

operation conditions for satisfying RF exposure compliance.

Antennas used for this OEM module must not exceed 3dBi gain for mobile and fixed

operating configurations.

7.2 GSM Antenna - PCB line Guidelines

Make sure that the impedance is 50Ω ;

Keep line on the PCB as short as possible, since the antenna line loss shall be less

than around 0,3 dB;

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

meanders and abrupt curves;

Any kind of suitable geometry / structure (Microstrip, Stripline, Coplanar, Grounded

Coplanar Waveguide...) can be used for implementing the printed transmission line

afferent the antenna;

If a Ground plane is required in line geometry, that plane has to 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 signal tracks on

different layers;

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

The ground surrounding the antenna line on PCB has to 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 line track;

Place EM noisy devices as far as possible from GE865 antenna line;

Keep the antenna line far away from the GE865 power supply lines;

If EM noisy devices are present on the PCB hosting the GE865, such as fast switching

ICs, take care of the shielding of the antenna line by burying it inside the layers of PCB

and surround it with Ground planes, or shield it with a metal frame cover.

If EM noisy devices are not present around the line, the use of geometries like

Microstrip or Grounded Coplanar Waveguide has to be preferred, since they typically

ensure less attenuation if compared to a Stripline having same length;

7.3 GSM Antenna - Installation Guidelines

Install the antenna in a place covered by the GSM signal.

If the device antenna is located greater then 20cm from the human body and there are

no co-located transmitter then the Telit FCC/IC approvals can be re-used by the end

product

If the device antenna is located less then 20cm from the human body or there are no

co-located transmitter then the additional FCC/IC testing may be required for the end

product (Telit FCC/IC approvals cannot be reused)

Antenna shall not be installed inside metal cases

Antenna shall be installed also according Antenna manufacturer instructions.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

8 Logic level specifications

Where not specifically stated, all the interface circuits work at 2.8V CMOS logic levels.

The following table shows the logic level specifications used in the GE865 interface

circuits:

Absolute Maximum Ratings -Not Functional

Parameter

Min

Max

Input level on any digital pin

(CMOS 2.8) when on

-0.3V

+3.1V

Input level on any digital pin

(CMOS 1.8) when on

-0.3V

+2.1V

Input voltage on analog pins

when on

-0.3V

+3.0 V

Operating Range - Interface levels (2.8V CMOS)

Level

Min

Max

Input high level

2.1V

3.1V

Input low level

0.5V

Output high level

2.2V

3.1V

Output low level

0.35V

For 1.8V signals:

Operating Range - Interface levels (1.8V CMOS)

Level

Min

Max

Input high level

1.6V

2.0V

Input low level

0.4V

Output high level

1,65V

2.0V

Output low level

0.35V

Current characteristics

Level

Typical

Output Current

1mA

Input Current

1uA

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

8.1 Reset signal

Signal

Function

I/O

Bga Ball

RESET#

Phone reset

RESET# is used to reset the GE865 . Whenever this signal is pulled low, the GE865 is

reset. When the device is reset it stops any operation. After the release of the reset

GE865 is unconditionally shut down, without doing any detach operation from the

network where it is registered. This behaviour is not a proper shut down because any

GSM device is requested to issue a detach request on turn off. For this reason the

Reset signal must not be used to normally shutting down the device, but only as an

emergency exit in the rare case the device remains stuck waiting for some network

response.

The RESET# is internally controlled on start-up to achieve always a proper power-on

reset sequence, so there's no need to control this pin on start-up. It may only be used

to reset a device already on that is not responding to any command.

NOTE:

Do not use this signal to power off the GE865. Use the ON/OFF signal to perform this

function or the AT#SHDN command.

Reset Signal Operating levels:

Signal

Min

Max

RESET Input high

1.8V*

2.1V

RESET Input low

0.2V

* this signal is internally pulled up so the pin can be left floating if not used.

If unused, this signal may be left unconnected. If used, then it must always be

connected with an open collector transistor, to permit to the internal circuitry the

power on reset and under voltage lockout functions.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

9 Serial Ports

The serial port on the GE865 is the core of the interface between the module and OEM

hardware.

2 serial ports are available on the module:

MODEM SERIAL PORT 1 (Main, ASC0)

MODEM SERIAL PORT 2 (Auxiliary, ASC1)

9.1 MODEM SERIAL PORT

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

the most common are:

RS232 PC com port

microcontroller UART @ 2.8V - 3V (Universal Asynchronous Receive Transmit)

microcontroller UART @ 5V or other voltages different from 2.8V

Depending from 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 doesn't need a

level translation is the 2.8V UART.

The serial port on the GE865 is a +2.8V UART with all the 7 RS232 signals. It differs from

the PC-RS232 in the signal polarity (RS232 is reversed) and levels. The levels for the

GE865 UART are the CMOS levels:

Absolute Maximum Ratings -Not Functional

Parameter

Min

Max

Input level on any

digital pad when on

-0.3V

+3.1V

Input voltage on analog

pads when on

-0.3V

+3.1V

Operating Range - Interface levels (2.8V CMOS)

Level

Min

Max

Input high level VIH

2.1V

3.1 V

Input low level VIL

0.5V

Output high level VOH

2.2V

3.1V

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

Output low level VOL

0.35V

The signals of the GE865 serial port are:

RS232

Number

Signal

GE865

Pad

Number

Name

Usage

DCD - dcd_uart

Data Carrier Detect

Output from the GE865 that indicates

the carrier presence

RXD -

tx_uart

Transmit line *see Note

Output transmit line of GE865 UART

TXD -

rx_uart

Receive line *see Note

Input receive of the GE865 UART

DTR - dtr_uart

Data Terminal Ready

Input to the GE865 that controls the

DTE READY condition

GND

C2, C7, E5,

E7, G1, G3,

G4, G5, H3,

Ground

ground

DSR - dsr_uart

Data Set Ready

Output from the GE865 that indicates

the module is ready

RTS -rts_uart

Request to Send

Input to the GE865 that controls the

Hardware flow control

CTS - cts_uart

Clear to Send

Output from the GE865 that controls

the Hardware flow control

RI - ri_uart

Ring Indicator

Output from the GE865 that indicates

the incoming call condition

NOTE:

According to V.24, RX/TX signal names are referred to the application side, therefore on

the GE865 side these signal are on the opposite direction: TXD on the application side

will be connected to the receive line (here named TXD/ rx_uart ) of the GE865 serial

port and viceversa for RX.

NOTE:

For a minimum implementation, only the TXD and RXD lines can be connected, the

other lines can be left open provided a software flow control is implemented.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

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 GE865 when the module is powered

off or during an ON/OFF transition.

9.2 RS232 level translation

In order to interface the GE865 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 0/2.8V 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 0-2.8V UART to the RS232 level.

The receiver is the translator from the RS232 level to 0-2.8V 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 2.8V CMOS have an absolute maximum input voltage

of 3.0V; therefore the level translator IC shall not be powered by the +3.8V supply of the

module. Instead, it must be powered from a +2.7V / +2.9V (dedicated) power supply.

This is because in this way the level translator IC outputs on the module side (i.e.

GE865 inputs) will work at +3.8V interface levels, damaging the module inputs.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

An example of level translation circuitry of this kind is:

The example is done with a SIPEX SP3282EB RS232 Transceiver that could accept

supply voltages lower than 3V DC.

NOTE:

In this case Vin has to be set with a value compatible with the logic levels of the

module. (Max 2.9V DC). In this configuration the SP3282EB will adhere to EIA/TIA-562

voltage levels instead of RS232 (-5 ~ +5V).

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

Second solution could be done using a MAXIM transceiver (MAX218) In this case the

compliance with RS232 (+-5V) is possible.

Another level adapting method could be done using a standard RS232 Transceiver

(MAX3237EAI) adding some resistors to adapt the levels on the GE865 Input lines.

NOTE: In this case has to be taken in account the length of the lines on the application

to avoid problems in case of High-speed rates on RS232.

The RS232 serial port lines are usually connected to a DB9 connector with the following

layout:

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

9.3 5V UART level translation

If the OEM application uses a microcontroller with a serial port (UART) that works at a

voltage different from 2.8 - 3V, then a circuitry has to be provided to adapt the different

levels of the two set of signals. As for the RS232 translation there are a multitude of

single chip translators. For example a possible translator circuit for a 5V

TRANSMITTER/RECEIVER can be:

TIP:

Note that the TC7SZ07AE has open drain output; therefore the resistor R2 is

mandatory.

NOTE:

The UART input line TXD (rx_uart) of the GE865 is NOT internally pulled up with a

resistor, so there may be the need to place an external 47KΩ pull-up resistor, either the

DTR (dtr_uart) and RTS (rts_uart) input lines are not pulled up internally, so an external

pull-up resistor of 47KΩ may be required.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

NOTE:

The input lines working at 2.8VCMOS can be pulled-up with 47KΩ

In case of reprogramming of the module has to be considered the use of the RESET line

to start correctly the activity.

The preferable configuration is having an external supply for the buffer.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

10 Audio Section Overview

The Base Band Chip of the GE865 provides one audio path both in Uplink

(

transmit

) and

Downlink

(receive)

direction , as shown in the next figure .

For more information refer to Telit document :

80000NT10007a Audio Settings Application Note

Audio Section Block Diagram

Single ended

Balanced

Single ended

Bias

MICN1

MIC 1

MICP1

100nF

MIC -

100nF

MIC +

xgoldafe.skd

Baseband Audio Front End

EPN1

EPP1

Ear +

Ear -

Earpiece Drivers 16 Load

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

10.1 Electrical Characteristics

TIP: Being the microphone circuitry the more noise sensitive, its design and layout

must be done with particular care. Both microphone paths are balanced and the

OEM circuitry must be balanced designed to reduce the common mode noise

typically generated on the ground plane. However the customer can use the

unbalanced circuitry for particular application.

10.1.1 Input Lines

differential microphone path

Line Coupling

AC*

Line Type

Balanced

Coupling capacitor

≥ 100nF

Differential input resistance

50kΩ

Differential input voltage

≤ 1,03Vpp @

MicG=0dB

(*) WARNING : AC means that the signals from the microphone have to be connected

to input lines of the module through capacitors which value has to be ≥ 100nF.

Not respecting this constraint, the input stages will be damaged.

WARNING: when particular OEM application needs a

Single Ended Input

configuration,

it is forbidden connecting the unused input directly to Ground, but only through a

capacitor which value has to be ≥ 100nF..

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

10.1.2 Output Lines

WARNING. When in

Single Ended

configuration, the unused output line must be left

open: if this constraint is not respected, the output stage will be damaged.

line coupling single-ended

differential

output load resistance

≥ 14 Ω

internal output resistance

4 Ω (

typical

)

signal bandwidth

150 ÷4000 Hz @ -3dB

max. differential output voltage

1.31 Vrms (

typical, open circuit

)

differential output voltage

328mVrms /16 Ω

@ -12dBFS (*)

volume increment

2 dB per step

volume steps

(*)

0dBFS

is the

normalized

overall Analog Gain equal to

3,7Vpp

differential

TIP : We suggest driving the load differentially , thus the output swing will double and

the need for the big output coupling capacitor avoided. However if particular OEM

application needs, also a Single Ended

(S.E)

circuitry can be implemented but the output

power will be reduced four times.

The OEM circuitry shall be designed to reduce the common mode noise typically

generated on the ground plane,getting the maximum power output from the device

(low resistance tracks).

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

11 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 ; they 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.

alternate function pad

is internally controlled by the GE865 firmware and acts

depending on the function implemented.

For Logic levels please refer to chapter 8.

The following table shows the available GPIO on the GE865 .

Signal

I/O

Function

Type

Input /

output

current

Default

State

ON_OFF

state

State

during

Reset

Note

GPIO_01

I/O

GPIO01 Configurable GPIO

CMOS 2.8V

1uA/1mA

INPUT

GPIO_02

I/O

GPIO02 Configurable GPIO

CMOS 2.8V

1uA/1mA

INPUT

Alternate function

(JDR)

GPIO_03

I/O

GPIO03 Configurable GPIO

CMOS 2.8V

1uA/1mA

INPUT

GPIO_04

I/O

GPIO04 Configurable GPIO

CMOS 2.8V

1uA/1mA

INPUT

Alternate function

(RF Transmission

Control)

GPIO_05

I/O

GPIO05 Configurable GPIO

CMOS 2.8V

1uA/1mA

INPUT

Alternate function

(RFTXMON)

GPIO_06

I/O

GPIO06 Configurable GPIO

CMOS 2.8V

1uA/1mA

INPUT

Alternate function

(ALARM)

GPIO_07

I/O

GPIO07 Configurable GPIO

CMOS 2.8V

1uA/1mA

INPUT

Alternate function

(BUZZER)

GPIO_08

I/O

GPIO08 Configurable GPIO

CMOS 2.8V

1uA/1mA

INPUT

GPIO_09

I/O

GPIO09 Configurable GPIO

CMOS 2.8V

Open Drain

GPIO_10

I/O

GPIO10 Configurable GPIO

CMOS 2.8V

Open Drain

Not all GPIO pads support all these three modes:

GPIO2 supports all three modes and can be input, output, Jamming Detect

Output (Alternate function)

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

GPIO4 supports all three modes and can be input, output, RF Transmission

Control (Alternate function)

GPIO5 supports all three modes and can be input, output, RFTX monitor output

(Alternate function)

GPIO6 supports all three modes and can be input, output, alarm output

(Alternate function)

GPIO7 supports all three modes and can be input, output, buzzer output

(Alternate function)

11.1 GPIO Logic levels

Where not specifically stated, all the interface circuits work at 2.8V CMOS logic levels.

The following table shows the logic level specifications used in the GE865 interface

circuits:

Absolute Maximum Ratings -Not Functional

Parameter

Min

Max

Input level on any digital pin

when on (CMOS 2.8)

-0.3V

+3.1V

Input level on any digital pin

when on (CMOS 1.8)

-0.3V

+2.1V

Input voltage on analog pins

when on

-0.3V

+3.0V

Operating Range - Interface levels (2.8V CMOS)

Level

Min

Max

Input high level

2.1V

3.1V

Input low level

0.5V

Output high level

2.2V

3.1V

Output low level

0.35V

For 1.8V signals:

Operating Range - Interface levels (1.8V CMOS)

Level

Min

Max

Input high level

1.6V

2.0V

Input low level

0.4V

Output high level

1,65V

1.85V

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

Output low level

0.35V

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

11.2 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 2.8V CMOS levels of the GPIO.

If the digital output of the device to be connected with the GPIO input pad has interface

levels different from the 2.8V CMOS, then it can be buffered with an open collector

transistor with a 47K pull up to 2.8V.

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 GE865 when the module is powered

off or during an ON/OFF transition.

11.3 Using a GPIO Pad as OUTPUT

The GPIO pads, when used as outputs, can drive 2.8V 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.

11.4 Using the RF Transmission Control GPIO4

The GPIO4 pin, when configured as RF Transmission Control Input, permits to disable

the Transmitter when the GPIO is set to Low by the application.

In the design is necessary to add a pull up resistor (47K to 2.8V);

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

11.5 Using the RFTXMON Output GPIO5

The GPIO5 pin, when configured as RFTXMON Output, is controlled by the GE865

module and will rise when the transmitter is active and fall after the transmitter activity

is completed.

There are 2 different modes for this function:

1) Active during all the calls:

For example, if a call is started, the line will be HIGH during all the conversation and it

will be again LOW after hanged up.

The line rises up 300ms before first TX burst and will became again LOW from 500ms

to 1s after last TX burst.

2) Active during all the TX activity:

The GPIO is following the TX bursts

Please refer to the AT User interface manual for additional information on how to

enable this function.

11.6 Using the Alarm Output GPIO6

The GPIO6 pad, when configured as Alarm Output, is controlled by the GE865 module

and will rise when the alarm starts and fall after the issue of a dedicated AT command.

This output can be used to power up the GE865 controlling microcontroller or

application at the alarm time, giving you the possibility to program a timely system

wake-up to achieve some periodic actions and completely turn off either the application

and the GE865 during sleep periods, dramatically reducing the sleep consumption to

few μA.

In battery-powered devices this feature will greatly improve the autonomy of the device.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

11.7 Using the Buzzer Output GPIO7

The GPIO7 pad, when configured as Buzzer Output, is controlled by the GE865 module

and will drive a Buzzer driver with appropriate square waves.

This permits to your application to easily implement Buzzer feature with ringing tones

or melody played at the call incoming, tone playing on SMS incoming or simply playing

a tone or melody when needed.

A sample interface scheme is included below to give you an idea of how to interface a

Buzzer to the GPIO7:

TR1

BCR141W

TR2

SMBT2907A

4,7K

D1N4148 C1

33pF +

+V buzzer

GPIO7

NOTE:

To correctly drive a buzzer a driver must be provided, its characteristics depend on the

Buzzer and for them refer to your buzzer vendor

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

11.8 Magnetic Buzzer Concepts

11.8.1 Short Description

A magnetic Buzzer is a sound-generating device with a coil located in the magnetic

circuit consisting of a permanent magnet, an iron core, a high permeable metal disk

and a vibrating diaphragm.

Drawing of the Magnetic Buzzer.

The disk and diaphragm are attracted to the core by the magnetic field. When an

oscillating signal is moved through the coil, it produces a fluctuating magnetic field

which vibrates the diaphragm at a frequency of the drive signal. Thus the sound is

produced relative to the frequency applied.

Diaphragm movement.

11.8.2 Frequency Behaviour

The frequency behaviour represents the effectiveness of the reproduction of the applied

signals. Because performance is related to a square driving waveform (whose

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

amplitude varies from 0V to Vpp), if you modify the waveform (

e.g. from square to sinus

)

the frequency response will change.

11.8.3 Power Supply Influence

Applying a signal whose amplitude is different from that suggested by the

manufacturer, the performance change o

Because resonance frequency depends on acoustic design, by lowering the amplitude

of the driving signal the response bandwidth tends to become narrow, and vice versa.

Summarizing: Vpp ↑  fo ↓ Vpp ↓ fo ↑

The risk is that the fo could easily fall outside of new bandwidth; consequently the SPL

could be much lower than the expected.

11.8.4 Working Current Influence

In the component data sheet you will find the value of MAX CURRENT: this represents

the maximum average current that can flow at nominal voltage without current

limitation. In other words it is not the peak current, which could be twice or three times

higher. If driving circuitry does not support these peak values, the SPL will never reach

the declared level or the oscillations will stop.

WARNING:

It is very important to respect the sense of the applied voltage: never apply to the

"-"

a voltage more positive than the

"+" pin

: if this happens, the diaphragm vibrates in

the opposite direction with a high probability to be expelled from its physical position.

This damages the device permanently.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

11.9 Indication of network service availability

The STAT_LED pin status shows information on the network service availability and

Call status.

In the GE865 modules, the STAT_LED usually needs an external transistor to drive an

external LED.

Therefore, the status indicated in the following table is reversed with respect to the pin

status.

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

A schematic example could be:

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

11.10 RTC Bypass out

The VRTC pin brings out the Real Time Clock supply, which is separate from the rest of

the digital part, allowing having only RTC going on when all the other parts of the device

are off.

To this power output a backup capacitor can be added in order to increase the RTC

autonomy during power off of the battery. NO Devices must be powered from this pin.

11.11 External SIM Holder Implementation

Please refer to the related User Guide (SIM Holder Design Guides, 80000NT10001a).

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

12 DAC and ADC section

12.1 DAC Converter

12.1.1 Description

The GE865 provides a Digital to Analog Converter. The signal (named DAC_OUT) is

available on BGA Ball G7 of the GE865 and on pin 17 of PL102 on GE865 Interface Board

(CS1324).

The on board DAC is a 10 bit converter, able to generate a analogue value based a

specific input in the range from 0 up to 1023. However, an external low-pass filter is

necessary

Min

Max

Units

Voltage range (filtered)

2,6

Volt

Range

1023

Steps

The precision is 10 bits so, if we consider that the maximum voltage is 2V, the

integrated voltage could be calculated with the following formula:

Integrated output voltage = (2 *value) / 1023

DAC_OUT line must be integrated (for example with a low band pass filter) in order to

obtain an analog voltage.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

12.1.2 Enabling DAC

AT command

is available to use the DAC function.

The command is: AT#DAC= [

<enable

> [,

<value>

]]

<value>

- scale factor of the integrated output voltage (0..1023 - 10 bit precision)

it must be present if

<enable>=1

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

this function.

NOTE:

The DAC frequency is selected internally. D/A converter must not be used during

POWERSAVING.

12.1.3 Low Pass Filter Example

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

12.2 ADC Converter

12.2.1 Description

The on board A/D are 11-bit converter. They are able to read a voltage level in the range

of 0÷2 volts applied on the ADC pin input, store and convert it into 11 bit word.

Min

Max

Units

Input Voltage range

Volt

AD conversion

bits

Resolution

< 1

The GE865 module provides 2 Analog to Digital Converters.

The input lines are:

ADC_IN1

available on Ball F5 and Pin 19 of PL102 on GE865 Interface Board

(CS1324)

ADC_IN2

available on Ball F6 and Pin 20 of PL102 on GE865 Interface Board

(CS1324)

12.2.2 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.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

13 Mounting the GE865 on your Board

13.1 General

The GE865 modules have been designed in order to be compliant with a standard lead-

free SMT process.

13.2 Module finishing & dimensions

Lead-free Alloy:

Surface finishing Sn/Ag/Cu for all solder pads

Pin A1

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

13.3 Recommended foot print for the application

In order to easily rework the GE865 is suggested to consider on the application a 1.5mm

Inhibit area around the module.

It is also suggested, as 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 INHIBIT WIRING *1 (see

figure) must be clear from signal or ground paths.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

13.4 Debug of the GE865 in production

To test and debug the mounting of the GE865, we strongly recommend to foreseen test pads

on the host PCB, in order to check the connection between the GE865 itself and the

application and to test the performance of the module connecting it with an external

computer. Depending by the customer application, these pads include, but are not limited to

the following signals:

TXD

RXD

ON/OFF

RESET

GND

VBATT

TX_AUX

RX_AUX

PWRMON

SERVICE

13.5 Stencil

a thickness of stencil foil ≥ 120µm.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

13.6 PCB pad design

Recommendations for PCB pad dimensions

Ball pitch [mm]

2,4

Solder resist opening diameter A [mm]

1,150

Metal pad diameter B [mm]

1 ± 0.05

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

It is recommended no microvia without solder resist cover under the module and no

microvia around the pads (see following figure).

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

Recommendations for PCB pad surfaces:

Finish

Layer thickness [µm]

Properties

Electro-less Ni

/ Immersion Au

3 7 /

0.05 0.15

good solder ability protection,

high shear force values

The PCB must be able to resist the higher temperatures which are occurring at the lead-

free process. This issue should be discussed with the PCB-supplier. Generally, the

wettability of tin-lead solder paste on the described surface plating is better compared to

lead-free solder paste.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

13.7 Solder paste

Lead free

Solder paste

Sn/Ag/Cu

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

13.7.1 GE865 Solder reflow

The following is the recommended solder reflow profile

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.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

NOTE:

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

surface

WARNING:

The GE865 module withstands one reflow process only.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

14 Packing system

The GE865 modules are packaged on trays of

pieces each. This is especially suitable

for the GE865 according to SMT processes for pick & place movement requirements.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

NOTE:

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

surface

WARNING:

These trays can withstand at the maximum temperature of 65° C.

14.1 Moisture sensibility

J-STD-020, take care all the relatives requirements for using this kind of components.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

15 Conformity Assessment Issues

The Telit GE865 Module has been assessed in order to satisfy the essential requirements of the

R&TTE Directive 1999/05/EC (Radio Equipment & Telecommunications Terminal Equipments) to

demonstrate the conformity against the harmonised standards with the final involvement of a Notified

Body.

If the module is installed in conformance to the Telit installation manuals, no further evaluation under

Article 3.2 of the R&TTE Directive and do not require further involvement of a R&TTE Directive

Notified Body for the final product.

In all other cases, or if the manufacturer of the final product is in doubt, then the equipment

integrating the radio module must be assessed against Article 3.2 of the R&TTE Directive.

In all cases the assessment of the final product must be made against the Essential requirements of

the R&TTE Directive Articles 3.1(a) and (b), Safety and EMC respectively, and any relevant Article 3.3

requirements.

This Hardware User Guide contain all the information you may need for developing a product meeting

the R&TTE Directive.

Furthermore the GE865 Module module is FCC Approved as module to be installed in other devices.

This device is to be used only for fixed and mobile applications. If the final product after integration is

intended for portable use, a new application and FCC is required.

The GE865 Module is conforming to the following US Directives:

Use of RF Spectrum. Standards: FCC 47 Part 24 (GSM 1900)

EMC (Electromagnetic Compatibility). Standards: FCC47 Part 15

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two

conditions:

(1) this device may not cause harmful interference, and

(2) this device must accept any interference received, including interference that may cause undesired

operation.

To meet the FCC's RF exposure rules and regulations:

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

The system antenna(s) used for this transmitter must be installed to provide a separation distance

of at least 20 cm from all the persons and must not be co-located or operating in conjunction with

any other antenna or transmitter.

The system antenna(s) used for this module must not exceed 1.4dBi (850MHz) and 3.0dBi

(1900MHz) for mobile and fixed or mobile operating configurations.

Users and installers must be provided with antenna installation instructions and transmitter

operating conditions for satisfying RF exposure compliance.

Manufacturers of mobile, fixed or portable devices incorporating this module are advised to clarify

any regulatory questions and to have their complete product tested and approved for FCC

compliance.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

16 SAFETY RECOMMANDATIONS

READ CAREFULLY

Be sure the use of this product is allowed in the country and in the environment

required. The use of this product may be dangerous and has to be avoided in the

following areas:

 Where it can interfere with other electronic devices in environments such as

hospitals, airports, aircrafts, etc

 Where there is risk of explosion such as gasoline stations, oil refineries, etc

It is responsibility of the user to enforce the country regulation and the specific

environment regulation.

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

validity.

We recommend following the instructions of the hardware user guides for a correct

wiring of the product. The product has to be supplied with a stabilized voltage source

and the wiring has to be conforming to the security and fire prevention regulations.

The product has to be handled with care, avoiding any contact with the pins because

electrostatic discharges may damage the product itself. Same cautions have to be

taken for the SIM, checking carefully the instruction for its use. Do not insert or remove

the SIM when the product is in power saving mode.

The system integrator is responsible of the functioning of the final product; therefore,

care has to be taken to the external components of the module, as well as of any

project or installation issue, because the risk of disturbing the GSM network or external

devices or having impact on the security. Should there be any doubt, please refer to the

technical documentation and the regulations in force.

Every module has to be equipped with a proper antenna with specific characteristics.

The antenna has to be installed with care in order to avoid any interference with other

electronic devices and has to guarantee a minimum distance from the body (20 cm). In

case of this requirement cannot be satisfied, the system integrator has to assess the

final product against the SAR regulation.

GE865 Hardware User Guide

1vv0300799 Rev.11 – 13-07-2010

The European Community provides some Directives for the electronic equipments

Community website:

http://europa.eu.int/comm/enterprise/rtte/dir99-5.htm

The text of the Directive 99/05 regarding telecommunication equipments is available,

while the applicable Directives (Low Voltage and EMC) are available at:

http://europa.eu.int/comm/enterprise/electr_equipment/index_en.htm

Telit Communications S p A GE865C Quadband GSM/ GPRS Module User Manual GE865 Harware User Guide

Telit Communications S.p.A. Quadband GSM/ GPRS Module GE865 Harware User Guide

User Manual

Navigation menu

Namespaces

Views

Navigation