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GE864-AUTO Hardware User Guide

1vv0300779 Rev.0 - 20/06/08

GE864-AUTO Hardware User Guide

1vv0300779 Rev.0 - 20/06/08

This document is relating to the following products:

GE864-AUTO 3990250701

GE864-AUTO Hardware User Guide

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Contents

1 Overview ...........................................................................................................................6

2 GE864-AUTO Mechanical Dimensions ...........................................................................7

3 GE864-AUTO module connections .................................................................................8

3.1 PIN-OUT...................................................................................................................................8

3.1.1 BGA Balls Layout........................................................................................................................... 12

4 Hardware Commands ....................................................................................................14

4.1 Turning ON the GE864-AUTO module ................................................................................14

4.2 Turning OFF the GE864-AUTO ............................................................................................16

4.2.1 Hardware shutdown....................................................................................................................... 16

4.2.2 Hardware Unconditional Restart.................................................................................................... 16

5 Power Supply .................................................................................................................18

5.1 Power Supply Requirements...............................................................................................18

5.2 General Design Rules ..........................................................................................................20

5.2.1 Electrical Design Guidelines .......................................................................................................... 20

5.2.1.1 + 5V input Source Power Supply Design Guidelines ................................................................ 20

5.2.1.2 + 12V input Source Power Supply Design Guidelines .............................................................. 21

5.2.1.3 Battery Source Power Supply Design Guidelines ..................................................................... 23

5.2.2 Thermal Design Guidelines ........................................................................................................... 24

5.2.3 Power Supply PCB layout Guidelines ........................................................................................... 25

6 Antenna...........................................................................................................................26

6.1 GSM Antenna Requirements ...............................................................................................26

6.2 GSM Antenna - PCB line Guidelines...................................................................................27

6.3 GSM Antenna - Installation Guidelines ..............................................................................28

7 Logic level specifications..............................................................................................29

7.1 Reset signal ..........................................................................................................................30

8 Serial Ports .....................................................................................................................31

8.1 MODEM SERIAL PORT.........................................................................................................31

8.2 RS232 level translation ........................................................................................................33

8.3 5V UART level translation....................................................................................................35

9 Audio Section Overview ................................................................................................37

9.1 INPUT LINES (Microphone) .................................................................................................38

9.1.1 Short description............................................................................................................................ 38

9.1.2 Input Lines Characteristics ............................................................................................................ 39

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9.2 OUTPUT LINES (Speaker)....................................................................................................40

9.2.1 Short description............................................................................................................................ 40

9.2.2 Output Lines Characteristics.......................................................................................................... 41

10 General Purpose I/O.......................................................................................................42

10.1 GPIO Logic levels .............................................................................................................44

10.2 Using a GPIO Pad as INPUT.............................................................................................45

10.3 Using a GPIO Pad as OUTPUT.........................................................................................45

10.4 Using the RF Transmission Control GPIO4....................................................................45

10.5 Using the RFTXMON Output GPIO5 ................................................................................46

10.6 Using the Alarm Output GPIO6........................................................................................47

10.7 Using the Buzzer Output GPIO7 ......................................................................................47

10.8 Indication of network service availability .......................................................................48

10.9 RTC Bypass out ................................................................................................................49

10.10 External 32KHz oscillator.................................................................................................49

11 ADC section....................................................................................................................51

11.1 ADC Converter ..................................................................................................................51

11.1.1 Description..................................................................................................................................... 51

11.1.2 Using ADC Converter .................................................................................................................... 51

11.2 Mounting the GE864-AUTO on your Board ....................................................................52

11.2.1 General .......................................................................................................................................... 52

11.2.2 Module finishing & dimensions ...................................................................................................... 52

11.2.3 Recommended foot print for the application (GE864) ................................................................... 53

11.2.4 Debug of the GE864 in production ................................................................................................54

11.2.5 Stencil ............................................................................................................................................ 54

11.2.6 PCB pad design............................................................................................................................. 55

11.2.7 Solder paste................................................................................................................................... 56

11.2.8 GE864 Solder reflow...................................................................................................................... 57

11.3 Packing system.................................................................................................................58

11.3.1 GE864 orientation on the tray........................................................................................................ 59

11.3.2 Moisture sensibility ........................................................................................................................ 59

12 Conformity Assessment Issues....................................................................................60

13 SAFETY RECOMMANDATIONS.....................................................................................61

14 Document Change Log ..................................................................................................62

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DISCLAIMER

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

S.p.A. and its affiliates (“TELIT”). The contents are confidential 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.

GE864-AUTO Hardware User Guide

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1 Overview

The aim of this document is the description of some hardware solutions useful for developing a product with the

Telit GE864-AUTO 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 GE864-AUTO module.

For further hardware details that may not be explained in this document refer to the Telit GE864-AUTO Product

Description document where all the hardware information is reported.

NOTICE

(EN) The integration of the GSM/GPRS GE864-AUTO cellular module within user application shall be done

according to the design rules described in this manual.

(IT) L’integrazione del modulo cellulare GSM/GPRS GE864-AUTO all’interno dell’applicazione dell’utente

dovrà rispettare le indicazioni progettuali descritte in questo manuale.

(DE) Die integration des GE864-AUTO GSM/GPRS Mobilfunk-Moduls in ein Gerät muß gemäß der in

diesem Dokument beschriebenen Kunstruktionsregeln erfolgen

(SL) Integracija GSM/GPRS GE864-AUTO modula v uporabniški aplikaciji bo morala upoštevati projektna

navodila, opisana v tem piročniku.

(SP) La utilización del modulo GSM/GPRS GE864-AUTO debe ser conforme a los usos para los cuales ha

sido deseñado descritos en este manual del usuario.

(FR) L’intégration du module cellulaire GSM/GPRS GE864-AUTO dans l’application de l’utilisateur sera

faite selon les règles de conception décrites dans ce manuel.

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.

GE864-AUTO

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2 GE864-AUTO Mechanical Dimensions

The Telit GE864-AUTO module overall dimension are:

• Length: 30 mm

• Width: 30 mm

• Thickness: 2.8 mm

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3 GE864-AUTO module connections

3.1 PIN-OUT

Ball Signal I/O Function Internal PULL UP Type

Audio

F9 AXE I Handsfree switching 100K CMOS 2.8V

G8 MIC_HF+ AI Handsfree mic. input; phase +, nom. level

3mVrms Audio

G9 MIC_MT- AI Handset mic.signal input; phase-, nom. level

50mVrms Audio

G10 EAR_MT+ AO Handset earphone signal output, phase + Audio

J8 MIC_MT+ AI Handset mic.signal input; phase+, nom. level

50mVrms Audio

J9 MIC_HF- AI Handsfree mic.input; phase -, nom. level

3mVrms Audio

J10 EAR_HF- AO Handsfree ear output, phase - Audio

H9 EAR_MT- AO Handset earphone signal output, phase - Audio

H10 EAR_HF+ AO Handsfree ear output, phase + Audio

SIM card interface

C10 SIMCLK O External SIM signal – Clock 1,8 / 3V

C11 SIMIN I External SIM signal - Presence (active low) 47K 1,8 / 3V

D4 SIMVCC - External SIM signal – Power supply for the SIM 1,8 / 3V

D10 SIMIO I/O External SIM signal - Data I/O 1,8 / 3V

E9 SIMRST O External SIM signal – Reset 1,8 / 3V

Trace

D11 TX_TRACE O TX Data for debug monitor CMOS 2.8V

F10 RX_TRACE I RX Data for debug monitor CMOS 2.8V

Prog. / Data + HW Flow Control

B6 C125/RING O Output for Ring indicator signal (RI) to DTE CMOS 2.8V

B7 C108/DTR I Input for Data terminal ready signal (DTR) from

DTE CMOS 2.8V

D9 C109/DCD O Output for Data carrier detect signal (DCD) to

DTE CMOS 2.8V

E7 C103/TXD I Serial data input (TXD) from DTE CMOS 2.8V

E11 C107/DSR O Output for Data set ready signal (DSR) to DTE CMOS 2.8V

F7 C105/RTS I Input for Request to send signal (RTS) from

DTE CMOS 2.8V

F6 C106/CTS O Output for Clear to send signal (CTS) to DTE CMOS 2.8V

H8 C104/RXD O Serial data output to DTE CMOS 2.8V

IIC

D2 IIC_SDA_HW I/O IIC HW interface /Configurable GPIO CMOS 2.8V

E1 IIC_SCL_HW I/O IIC HW interface /Configurable GPIO CMOS 2.8V

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Ball Signal I/O Function Internal PULL UP Type

DAC and ADC

J11 ADC_IN1 AI Analog/Digital converter input A/D

H11 ADC_IN2 AI Analog/Digital converter input A/D

G11 ADC_IN3 AI Analog/Digital converter input A/D

Miscellaneous Functions

A2 RESET* I Reset input

D8 STAT_LED O Status indicator led CMOS 1.8V

E2 VRTC AO VRTC Power

F3 32K_IN I 32.768 KHz Square Wave Input CMOS 1.8V

J5 ON_OFF* I

Input command for switching power ON or OFF

(toggle command). The pulse to be sent to the

GE864 must be equal or greater than 1

second.

47K Pull up to VBATT

L8 PWRMON O Power ON Monitor CMOS 2.8V

L4 Antenna O Antenna output – 50 ohm RF

Telit GPIO

E6 TGPIO_01 / JDR I/O Telit GPIO01 I/O pin / Jammer detect report CMOS 2.8V

H5 TGPIO_02/PCM_WAO I/O Telit GPIO02 Configurable GPIO / PCM audio * CMOS 2.8V

K7 TGPIO_03 / PCM_RX I/O Telit GPIO03 Configurable GPIO / PCM audio * CMOS 2.8V

B3 TGPIO_04 I/O Telit GPIO04 Configurable GPIO / RF

Transmission Control CMOS 2.8V

K8 TGPIO_05 / RFTXMON I/O Telit GPIO05 Configurable GPIO / Transmitter

ON monitor CMOS 2.8V

B5 TGPIO_06 / ALARM I/O Telit GPIO06 Configurable GPIO / ALARM CMOS 2.8V

L9 TGPIO_07 / BUZZER I/O Telit GPIO07 Configurable GPIO / Buzzer CMOS 2.8V

H3 TGPIO_08 / PCM_TX I/O Telit GPIO08 Configurable GPIO / PCM audio * CMOS 2.8V

D7 PCM_CLK I/O Configurable GPIO / PCM audio * CMOS 2.8V

Power Supply

J1 VBATT - Main power supply Power

K1 VBATT - Main power supply Power

J2 VBATT - Main power supply Power

K2 VBATT - Main power supply Power

A1 GND - Ground Power

F1 GND - Ground Power

H1 GND - Ground Power

L1 GND - Ground Power

H2 GND - Ground Power

L2 GND - Ground Power

J3 GND - Ground Power

K3 GND - Ground Power

L3 GND - Ground Power

K4 GND - Ground Power

K5 GND - Ground Power

D6 GND - Ground Power

K6 GND - Ground Power

L6 GND - Ground Power

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Ball Signal I/O Function Internal PULL UP Type

A11 GND - Ground Power

F11 GND - Ground Power

L11 GND - Ground Power

RESERVED

A10

B10

B11

E10

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Ball Signal I/O Function Internal PULL UP Type

K10

K11

L10

* Ref. to Digital Voice Interface Application Note 80000NT10004a.

NOTE: RESERVED pins must not be connected

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

pins:

pin signal

J1,K1,J2,K2 VBATT

A1,F1,H1,L1,H2,L2,J3,K3,L3,

K4,K5,D6,K6,L6,A11,F11,L11

GND

J5 ON/OFF*

E7 TXD

A2 RESET*

H8 RXD

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3.1.1 BGA Balls Layout

TOP VIEW

A B C D E F G H J K L

1 GND - - - IIC_SCL_

HW GND - GND VBATT VBATT GND

2 RESET* - - IIC_SDA_

HW VRTC - - GND VBATT VBATT GND

3 - TGPIO_04 - - - 32K_IN -

TGPIO_08

/ PCM_TX GND GND GND

4 -- - - SIMVCC - - - - - GND Antenna

5 - TGPIO_06

/ ALARM - - - - -

TGPIO_02 /

PCM_WAO ON_OFF* GND -

6 - C125/RING - GND TGPIO_01

/ JDR

C106 /

CTS - - - GND GND

7 - C108 /

DTR - PCM_CLK C103 /

TXD

C105 /

RTS - - - TGPIO_03/

PCM_RX -

8 - - -

STAD_

LED - - MIC_HF+ C104 /

RXD MIC_MT+

TGPIO_05

RFTXMON

PWRMON

9 - - - C109 /

DCD SIMRST AXE MIC_MT- EAR_MT- MIC_HF- -

TGPIO_07

/ BUZZER

10 - - SIMCLK SIMIO - RX_TRACE EAR_MT+ EAR_HF+ EAR_HF- - -

11 GND - SIMIN TX_TRACE C107 /

DSR GND ADC_IN3 ADC_IN2 ADC_IN1 - GND

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AUDIO Signals balls

SIM CARD interface balls

TRACE Signals balls

Prog. / data + Hw Flow Control signals balls

IIC

DAC and ADC signals balls

MISCELLANEOUS functions signals balls

TELIT GPIO balls

POWER SUPPLY VBATT balls

POWER SUPPLY GND balls

RESERVED

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4 Hardware Commands

4.1 Turning ON the GE864-AUTO module

To turn on the GE864-AUTO the pad ON* must be tied low for at least 1 seconds and then released.

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 GE864-AUTO power regulator and improper power on/off of the module. The line ON* must

be connected only in open collector configuration.

NOTE: In this document all the lines that are inverted, hence have active low signals are labeled with a name that

ends with a "*" .

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.

ON*

Power ON impulse

GND

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For example:

1- Let's assume you need to drive the ON* pad with a totem pole output from +1.8V up to 5V

microcontroller (uP_OUT1):

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

10k

ON*

1.8V ... 5V

ON*

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4.2 Turning OFF the GE864-AUTO

The turning off of the device can be done in three ways:

• by software command (see GE864-AUTO Software User Guide)

• by hardware shutdown

• by Hardware Unconditional Restart

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.

4.2.1 Hardware shutdown

To turn OFF the GE864-AUTO the pad ON* must be tied low for at least 2 seconds and then released.

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

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

TIP: To check if the device has powered off, the hardware line PWRMON should be monitored. When PWRMON goes

low, the device has powered off.

4.2.2 Hardware Unconditional Restart

To unconditionally Restart the GE864-AUTO, the pad RESET* must be tied low for at least 200

milliseconds and then released.

A simple circuit to do it is:

RESET*

Unconditional Restart

impulse

GND

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NOTE: don't 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 GE864-AUTO power regulator and improper functioning of the module. The

line RESET* must be connected only in open collector configuration.

TIP: The unconditional hardware Restart should be always implemented on the boards and software should use it

as an emergency exit procedure.

For example:

1- Let's assume you need to drive the RESET* pad with a totem pole output from +1.8V up to +5V

microcontroller (uP_OUT2):

10k

RESET*

.8V ... 5V

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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 product overall performances, hence read carefully the requirements and

the guidelines that will follow for a proper design.

5.1 Power Supply Requirements

POWER SUPPLY

Nominal Supply Voltage 3.8V

Max Supply Voltage 4.2V

Operating Supply Voltage Range 3.4V – 4.2V

Wide Supply Voltage tolerant 3.25V – 4.2V

TIP: the supply voltage is directly measured between VBATT and GND balls. It must stay within the Wide Supply

Voltage tolerant range including any drop voltage and overshoot voltage (during the slot tx, for example).

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The GE864-AUTO power consumptions are:

GE864-AUTO

Mode Average (mA) Mode description

IDLE mode Stand by mode; no call in progress

AT+CFUN=1 23,9 Normal mode: full functionality of the module

AT+CFUN=4 22 Disabled TX and RX; module is not registered on the

network

AT+CFUN=0 or

AT+CFUN=5 7,20 / 3,561

Power saving: CFUN=0 module registered on the network

and can receive voice call or an SMS; but it is not possible

to send AT commands; module wakes up with an

unsolicited code (call or SMS) or rising RTS line. CFUN=5

full functionality with power saving; module registered on

the network can receive incoming calls and SMS

RX mode

1 slot in downlink 52,3

2 slot in downlink 65,2

3 slot in downlink 78,6

4 slot in downlink 88,4

GSM Receiving data mode

GSM TX and RX mode

Min power level 78,1

Max power level 200,1

GSM Sending data mode

GPRS (class 10) TX and RX mode

Min power level 123,7

Max power level 370,8

GPRS Sending data mode

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, 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.

TIP: The electrical design for the Power supply should be made ensuring it will be capable of a peak current output

of at least 2A.

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

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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 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

5.2.1.1 + 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 GE864-AUTO, 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 GE864-AUTO

from power polarity inversion.

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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 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 GE864-AUTO.

• 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.

• A protection diode should be inserted close to the power input, in order to save the GE864-AUTO

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

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

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5.2.1.3 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

GE864-AUTO module.

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

GE864-AUTO and damage it.

NOTE: DON'T USE any Ni-Cd, Ni-MH, and Pb battery types directly connected with GE864-AUTO. Their use

can lead to overvoltage on the GE864-AUTO 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 GE864-AUTO

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.

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5.2.2 Thermal Design Guidelines

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

• Average current consumption during transmission @PWR level max: 500mA

• Average current consumption during transmission @ PWR level min: 100mA

• Average current during Power Saving (CFUN=5): 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 GE864-AUTO, 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 GE864-AUTO; you must

ensure that your application can dissipate it.

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5.2.3 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 GE864-AUTO 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 GE864-AUTO 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 GE864-AUTO, then this noise is not so disturbing and power

supply layout design can be more forgiving.

• The PCB traces to the GE864-AUTO 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.

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6 Antenna

The antenna connection and board layout design are the most important part in the full product design

and they strongly reflect on the product overall performances, hence read carefully and follow the

requirements and the guidelines for a proper design.

6.1 GSM Antenna Requirements

As suggested on the Product Description the antenna and antenna line on PCB for a Telit GE864-

AUTO device shall fulfill 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 Gain < 3dBi

Impedance 50 ohm

Input power > 2 W peak power

VSWR absolute

max

<= 10:1

VSWR

recommended

<= 2:1

When using the Telit GE864-AUTO, since there's no antenna connector on the module, the antenna

must be connected to the GE864-AUTO through the PCB with the antenna pad.

In the case that the antenna is not directly developed on the same PCB, hence directly connected at

the antenna pad of the GE864-AUTO, then a PCB line is needed in order to connect with it or with its

connector.

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This line of transmission shall fulfill the following requirements:

ANTENNA LINE ON PCB REQUIREMENTS

Impedance 50 ohm

Max Attenuation 0,3 dB

No coupling with other signals allowed

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

the GE864-AUTO ground pins

Furthermore if the device is developed for the US market and/or Canada market, it shall comply to 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 GE864-AUTO

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

operating configurations.

6.2 GSM Antenna - PCB line Guidelines

• Ensure that the antenna line impedance is 50 ohm;

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

than 0,3 dB;

• Antenna line must have uniform characteristics, constant cross section, avoid meanders and

abrupt curves;

• Keep, if possible, one layer of the PCB used only for the Ground plane;

• Surround (on the sides, over and under) the antenna line on PCB with Ground, avoid having other

signal tracks facing directly the antenna line track;

• The ground around the antenna line on PCB has to be strictly connected to the Ground Plane by

placing vias once per 2mm at least;

• Place EM noisy devices as far as possible from GE864-AUTO antenna line;

• Keep the antenna line far away from the GE864-AUTO power supply lines;

• If you have EM noisy devices around the PCB hosting the GE864-AUTO, 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 you don't have EM noisy devices around the PCB of GE864-AUTO, by using a strip-line on the

superficial copper layer for the antenna line, the line attenuation will be lower than a buried one;

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6.3 GSM Antenna - Installation Guidelines

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

• The Antenna 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;

• Antenna shall not be installed inside metal cases

• Antenna shall be installed also according Antenna manufacturer instructions.

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7 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 Telit GE864-AUTO interface circuits:

Absolute Maximum Ratings -Not Functional

Parameter Min Max

Input level on any

digital pin when on

-0.3V +3.6V

Input voltage on

analog pins when on

-0.3V +3.0 V

Voltage on Buffered

pins

-0.3V 25V

Operating Range - Interface levels (2.8V CMOS)

Level Min Max

Input high level 2.1V 3.3V

Input low level 0V 0.5V

Output high level 2.2V 3.0V

Output low level 0V 0.35V

For 1,8V signals:

Operating Range - Interface levels (1.8V CMOS)

Level Min Max

Input high level 1.6V 2.2V

Input low level 0V 0.4V

Output high level 1,65V 2.2V

Output low level 0V 0.35V

Current characteristics

Level Typical

Output Current 1mA

Input Current 1uA

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7.1 Reset signal

Signal Function I/O Bga Ball

RESET Phone reset I A2

RESET is used to reset the GE864-AUTO modules. Whenever this signal is pulled low, the GE864-AUTO

is reset. When the device is reset it stops any operation. After the release of the reset GE864-AUTO 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 GE864-AUTO. Use the ON/OFF signal to perform this

function or the AT#SHDN command.

Reset Signal Operating levels:

Signal Min Max

RESET Input high 2.0V* 2.2V

RESET Input low 0V 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.

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8 Serial Ports

The serial port on the Telit GE864-AUTO is the core of the interface between the module and OEM

hardware.

2 serial ports are available on the module:

• MODEM SERIAL PORT

• MODEM SERIAL PORT 2 (DEBUG)

8.1 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 GE864-AUTO 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 GE864-AUTO

UART are the CMOS levels:

Absolute Maximum Ratings -Not Functional

Parameter Min Max

Input level on any

digital pad when on

-0.3V +3.6V

Input voltage on

analog pads when on

-0.3V +3.0 V

Operating Range - Interface levels (2.8V CMOS)

Level Min Max

Input high level VIH 2.1V 3.3V

Input low level VIL 0V 0.5V

Output high level VOH 2.2V 3.0V

Output low level VOL 0V 0.35V

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The signals of the GE864-AUTO serial port are:

RS232

Number

Signal GE864-

AUTO Pad

Number

Name Usage

1 DCD - dcd_uart D9 Data Carrier Detect Output from the GE864-AUTO that indicates the

carrier presence

2 RXD - tx_uart H8 Transmit line *see Note Output transmit line of GE864-AUTO UART

3 TXD - rx_uart E7 Receive line *see Note Input receive of the GE864-AUTO UART

4 DTR - dtr_uart B7 Data Terminal Ready Input to the GE864-AUTO that controls the DTE

READY condition

5 GND A1,F1,H1

L1, H2, L2,

J3, K3….

Ground ground

6 DSR - dsr_uart E11 Data Set Ready Output from the GE864-AUTO that indicates the

module is ready

7 RTS -rts_uart F7 Request to Send Input to the GE864-AUTO that controls the

Hardware flow control

8 CTS - cts_uart F6 Clear to Send Output from the GE864-AUTO that controls the

Hardware flow control

9 RI - ri_uart B6 Ring Indicator Output from the GE864-AUTO that indicates the

incoming call condition

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

the GE864 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 GE864-AUTO serial port and

viceversa for RX.

TIP: 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.

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8.2 RS232 level translation

In order to interface the Telit GE864-AUTO 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 0/3V 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 for 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 driver and receiver 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 0-3V UART level to the RS232 level, while the

receiver is the translator from RS232 level to 0-3V UART.

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

 5 driver

 3 receiver

NOTE: The digital input lines working at 2.8VCMOS have an absolute maximum input voltage

of 3,75V; therefore the level translator IC shall not be powered by the +3.8V supply of the

module. Instead it shall be powered from a +2.8V / +3.0V (dedicated) power supply.

This is because in this way the level translator IC outputs on the module side (i.e. GE864

inputs) will work at +3.8V interface levels, stressing the module inputs at its maximum input

voltage.

This can be acceptable for evaluation purposes, but not on production devices.

NOTE: In order to be able to do in circuit reprogramming of the GE864 firmware, the serial port

on the Telit GE864 shall be available for translation into RS232 and either it's controlling device

shall be placed into tristate, disconnected or as a gateway for the serial data when module

reprogramming occurs.

Only RXD, TXD, GND and the On/off module turn on pad are required to the reprogramming of

the module, the other lines are unused.

All applicator shall include in their design such a way of reprogramming the GE864.

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An example of level translation circuitry of this kind is:

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

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8.3 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: This logic IC for the level translator and 2.8V pull-ups (not the 5V one) can be powered directly from PWRMON

line of the GE864-AUTO. Note that the TC7SZ07AE has open drain output, therefore the resistor R2 is mandatory.

TO TELIT

MODULE

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NOTE: The UART input line TXD (rx_uart) of the GE864-AUTO 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.

A power source of the internal interface voltage corresponding to the 2.8VCMOS high level is

available at the PWRMON pin on the connector, whose absolute maximum output current is 1mA.

A maximum of 9 resistors of 47 KΩ pull-up can be connected to the PWRMON pin, provided no other

devices are connected to it and the pulled-up lines are GE864-AUTO input lines connected to open

collector outputs in order to avoid latch-up problems on the GE864-AUTO.

Care must be taken to avoid latch-up on the GE864-AUTO and the use of this output line to power

electronic devices shall be avoided, especially for devices that generate spikes and noise such as

switching level translators, micro controllers, failure in any of these condition can severely compromise

the GE864-AUTO functionality.

NOTE: The input lines working at 2.8VCMOS can be pulled-up with 47KΩ resistors that can be connected directly to

the PWRMON line provided they are connected as in this example.

NO OTHER devices than those suggested should be powered with the PWRMON line; otherwise the module

functionality may be compromised.

It is important to consider that the added circuit must have consumption lower than 1mA.

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.

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9 Audio Section Overview

The Base Band Chip of the GE864-AUTO Telit Module provides two different audio blocks; both in

transmit (Uplink) and in receive (Downlink) direction:

“MT lines” should be used for handset function,

“HF lines” is suited for hands -free function (car kit).

These two blocks can be active only one at a time, selectable by AXE hardware line or by AT

command.The audio characteristics are equivalent in transmit blocks, but are different in the receive

ones and this should be kept in mind when designing.

GE863-GPS Audio Paths

Differential

Line-Out Drivers

Fully Differential

Power Buffers

EXTERNAL

AMPLIFIER

-12dBFS

+10dB

-45dBV/Pa

Mic_HF-Ear_HF-

Balanced

Single

ended

Mic_HF+Ear_HF+

50cm23mVrms

0,33mV rms

audio2.skd

GM863-GPS

+20dB

7cm-45dBV/Pa

3,3mVrms

365mVrms

Mic_MT+Ear_MT+

Mic_MT-Ear_MT-

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9.1 INPUT LINES (Microphone)

9.1.1 Short description

The Telit GE864-AUTO provides two audio paths in transmit section. Only one of the two paths can

be active at a time, selectable by AXE hardware line or by AT command.

You must keep in mind the different audio characteristics of the transmit blocks when designing:

The “MIC_MT” audio path should be used for handset function, while the “MIC_HF” audio path is

suited for hands-free function (car kit).

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 should

be balanced designed to reduce the common mode noise typically generated on the ground

plane. However also an unbalanced circuitry can be used for particular OEM application needs.

TIP: due to the difference in the echo canceller type, the “Mic_MT” audio path is suited for

Handset applications, while the “Mic_HF”audio path is suited for hands-free function (car kit).

The Earphone applications should be made using the “Mic_HF” audio path but DISABLING the

echo canceller by software AT command. If the echo canceller is left active with the Earphone,

then some echo might be introduced by the echo cancel algorithm.

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9.1.2 Input Lines Characteristics

“MIC_MT” 1st differential microphone path

Line Coupling AC*

Line Type Balanced

Coupling capacitor ≥ 100nF

Differential input resistance 50kΩ

Differential input voltage ≤ 1,03Vpp (365mVrms)

Microphone nominal sensitivity -45 dBVrms/Pa

Analog gain suggested + 20dB

Echo canceller type Handset

“MIC_HF” 2nd differential microphone path

Line Coupling AC*

Line Type Balanced

Coupling capacitor ≥ 100nF

Differential input resistance 50kΩ

Differential input voltage ≤ 65mVpp (23mVrms)

Microphone nominal sensitivity -45 dBVrms/Pa

Analog gain suggested +10dB

Echo canceller type Car kit hands-free

(*) WARNING: AC means that the signals from microphone has to be connected to input lines

of the module by a CAPACITOR, which value must be ≥ 100nF. Not respecting this constraint,

the input stage will be damaged.

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9.2 OUTPUT LINES (Speaker)

9.2.1 Short description

The Telit GE864-AUTO provides two audio paths in receive section. Only one of the two paths can be

active at a time, selectable by AXE hardware line or by AT command.

You must keep in mind the different audio characteristics of the receive blocks when designing:

Æ the “EAR_MT” lines EPN1 and EPP1 are the Differential Line-Out Drivers ; they can drive an

external amplifier or directly a 16 Ω earpiece at –12dBFS (*) ;

Æ the “EAR_HF” lines EPPA1_2 and EPPA2 are the Fully Differential Power Buffers ; they can

directly drive a 16Ω speaker in differential (balanced) or single ended (unbalanced) operation mode .

(*) FS : acronym of Full Scale. It is equal to 0dB, the maximum Hardware Analog Receive Gain of

BaseBand Chip.

The “EAR_MT” audio path should be used for handset function, while the “EAR_HF” audio path is

suited for hands-free function (car kit).

Both receiver outputs are B.T.L. type (Bridged Tie Load) and the OEM circuitry shall be designed

bridged to reduce the common mode noise typically generated on the ground plane and to get the

maximum power output from the device; however also a single ended circuitry can be designed for

particular OEM application needs.

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9.2.2 Output Lines Characteristics

“EAR_MT” Differential Line-out Drivers Path

Line Coupling DC

Line Type Bridged

Output load resistance ≥ 14 Ω

Internal output resistance 4 Ω (typical)

Signal bandwidth 150 – 4000 Hz @ -3 dB

Differential output voltage 328mVrms /16 Ω @ -12dBFS

SW volume level step - 2 dB

Number of SW volume steps 10

“EAR_HF” Power Buffers Path

Line Coupling DC

Line Type Bridged

Output load resistance ≥ 14 Ω

Internal output resistance 4 Ω ( >1,7 Ω )

Signal bandwidth 150 – 4000 Hz @ -3 dB

Max Differential output voltage 1310 mVrms (typ, open circuit)

Max Single Ended output voltage 656 mVrms (typ, open circuit)

SW volume level step - 2 dB

Number of SW volume steps 10

For more detailed information about audio please refer to the Audio Settings Application Note

80000NT10007a.

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10 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 GE864-AUTO firmware and acts depending on the function

implemented. For Logic levels please refer to chapter 7.

The following GPIO are available on the GE864-AUTO:

Ball Signal I/O Function Type

Input /

output

current

Default

State

during

Reset

Note

B3 TGPIO_04 I/O GPIO04 Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT x Alternate function (RF

Transmission Control)

B5 TGPIO_06 I/O GPIO06 Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT HIGH

(see Fig.01)

Alternate function

(ALARM)

E6 TGPIO_01 I/O GPIO01 Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT x Alternate function (JDR)

H3 TGPIO_08 I/O GPIO08 Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT x PCM_TX

H5 TGPIO_02 I/O GPIO02 Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT x PCM_WAO

K7 TGPIO_03 I/O GPIO03 Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT x PCM_RX

K8 TGPIO_05 I/O GPIO05 Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT x Alternate function

(RFTXMON)

L9 TGPIO_07 I/O GPIO07 Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT x Alternate function

(BUZZER)

D7 PCM_CLK I/O Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT x PCM audio *

Not all GPIO pads support all these three modes:

• GPIO1 supports all three modes and can be input, output, Jamming Detect Output (Alternate

function)

• 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)

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Fig.01

ch1: ON_OFF (2sec)

ch2: GPIO 06 [ bis ]

GE864-AUTO

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10.1 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 GE864-AUTO interface circuits:

Absolute Maximum Ratings -Not Functional

Parameter Min Max

Input level on any

digital pin when on

-0.3V +3.6V

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 3.3V

Input low level 0V 0.5V

Output high level 2.2V 3.0V

Output low level 0V 0.35V

For 1,8V signals:

Operating Range - Interface levels (1.8V CMOS)

Level Min Max

Input high level 1.6V 2.2V

Input low level 0V 0.4V

Output high level 1,65V 2.2V

Output low level 0V 0.35V

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10.2 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.

10.3 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.

10.4 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 PWRMON);

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10.5 Using the RFTXMON Output GPIO5

The GPIO5 pin, when configured as RFTXMON Output, is controlled by the GE864-AUTO module and

will rise when the transmitter is active and fall after the transmitter activity is completed.

The TXMON pin behaviour can be configured using the AT command

# TXMONMODE

This command will be available only under AT#SELINT=2.

# TXMONMODE – TTY-CTM DSP operating mode

# TXMONMODE – Set TXMON pin behaviour

AT# TXMONMODE

=<mode>

Set TXMON pin behaviour.

Parameter:

<mode>

0 – TXMON pin goes high when a call is started and it drops down when the call

is ended. It also goes high when a location update starts, and it drops down

when the location update procedure stops. Finally it goes high during SMS

transmission and receiving.

Even if the TXMON in this case is set as GPIO in output, the read command

AT#GPIO=5,2 returns #GPIO:2,0, as the GPIO is in alternate mode.

1 – TXMON is set in alternate mode and the Timer unit controls its

state. TXMON goes high 200μs before TXEN goes high. Then power

ramps start raising and there is the burst transmission. Finally TXMON

drops down 47μs after power ramps stop falling down. This behaviour is

repeated for every transmission burst.

Note 1: The parameter <mode> is saved in NVM.

Note 2: if user sets GPIO 5 as input or output the TXMON does not follow the

above behaviour.

Note 3: if <mode> is change during a call from 1 to 0, TXMON goes down. If it is

restored to 1, TXMON behaves as usual, following the bursts.

Note 4: this command is not supported in GM862 product family.

AT# TXMONMODE? Read command reports the <mode> parameter set value, in the format:

#TXMONMOD: <mode>

AT#TXMONMODE=? Test command reports the supported values for <mode> parameter.

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 1sec after

last TX burst.

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10.6 Using the Alarm Output GPIO6

The GPIO6 pad, when configured as Alarm Output, is controlled by the GE864-AUTO 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 GE864-AUTO 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 GE864-AUTO 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.

NOTE: During RESET the line is set to HIGH logic level.

10.7 Using the Buzzer Output GPIO7

The GPIO7 pad, when configured as Buzzer Output, is controlled by the GE864-AUTO module and

will drive with appropriate square waves a Buzzer driver.

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 by your application.

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

GPIO7:

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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.

10.8 Indication of network service availability

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

In the GE864-AUTO 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

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10.9 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.

10.10 External 32KHz oscillator

The GE864-AUTO has an internal 32.768 KHz oscillator for ‘power saving’ and ‘Real Time Clock’

features.

A common 32.768 KHz crystal is not reliable for ‘automotive’ applications.

For this reason, the GE864 AUTO will not have an internal oscillator, but the 32.768 KHz signal must

be fed in externally (ball F3).

This signal must be a square wave with following specifications:

Minimum Maximum Unit

L-input voltage -0.25 +0.2 V

H-input voltage 1.8 2.2 V

Input impedence > 10K Ω

If ‘power saving’ and ‘Real Time Clock’ features are not required, the signal 32K_IN (ball F3) must be

connected to ground.

32K

IN GE864

AUTO

ball

SQUARE

WAVE

32.768KHz

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A possible Clock Oscillator is shown in figure:

The Clock Oscillator should be placed close to GE864-AUTO.

The AT command used to test the presence and the status of an external 32KHz oscillator is

#OSC32KHZ

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

32K

IN GE864

AUTO

ball

MICRO CRYSTAL

OV-7604-C7

Low Power

Clock Oscillator

32.768KHz

CLKO UT

VDD

GND

CLKO E

V DD

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11 ADC section

11.1 ADC Converter

11.1.1 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.

Input Voltage range 0 ÷ 2 Volt

AD conversion 11 bits

Resolution 1 mV

The GE864-AUTO module provides 3 Analog to Digital Converters. The input lines are:

ADC_IN1 available on Ball J11 and Pin 19 of PL102 on EVK2 Board (CS1302).

ADC_IN2 available on Ball H11 and Pin 20 of PL102 on EVK2 Board (CS1302).

ADC_IN3 available on Ball G11 and Pin 21 of PL102 on EVK2 Board (CS1302).

11.1.2 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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11.2 Mounting the GE864-AUTO on your Board

11.2.1 General

The Telit GE864-AUTO modules have been designed in order to be compliant with a standard lead-free

SMT process.

11.2.2 Module finishing & dimensions

Lead-free Alloy:

Surface finishing Sn/Ag/Cu for all solder pads

Pin A1

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11.2.3 Recommended foot print for the application (GE864)

Top View

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11.2.4 Debug of the GE864 in production

To test and debug the mounting of the GE864, we strongly recommend to foreseen test pads on the

host PCB, in order to check the connection between the GE864 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_TRACE

• RX_TRACE

• PWRMON

11.2.5 Stencil

Stencil’s apertures layout can be the same of the recommended footprint (1:1), we suggest a

thickness of stencil foil ≥ 120µm.

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11.2.6 PCB pad design

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

Recommendations for PCB pad dimensions

Ball pitch [mm] 2,5

Solder resist opening diameter A [mm] 1,150

Metal pad diameter B [mm] 1 ± 0.05

Placement of microvias not covered by solder resist is not recommended inside the “Solder resist

opening”, unless the microvia carry the same signal of the pad itself.

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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.

11.2.7 Solder paste

Lead free

Solder paste Sn/Ag/Cu

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11.2.8 GE864 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.

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

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11.3 Packing system

The Telit GE864 modules are packaged on trays of 20 pieces each. This is especially suitable for the

GE864 according to SMT processes for pick & place movement requirements.

The size of the tray is: 329 x 176mm

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

Section A-A

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11.3.1 GE864 orientation on the tray

11.3.2 Moisture sensibility

The level of moisture sensibility of GE864 module is “3”, in according with standard IPC/JEDEC J-STD-

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

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12 Conformity Assessment Issues

The GE864-AUTO module is assessed to be conform to the R&TTE Directive as stand-alone

products, so If the module is installed in conformance with Dai Telecom installation instructions require

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 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.

The GE864-AUTO module is conform with the following European Union Directives:

• R&TTE Directive 1999/5/EC (Radio Equipment & Telecommunications Terminal Equipments)

• Low Voltage Directive 73/23/EEC and product safety

• Directive 89/336/EEC for conformity for EMC

In order to satisfy the essential requisite of the R&TTE 99/5/EC directive, the GE864-AUTO

module is compliant with the following standards:

• GSM (Radio Spectrum). Standard: EN 301 511 and 3GPP 51.010-1

• EMC (Electromagnetic Compatibility). Standards: EN 301 489-1 and EN 301 489-7

• LVD (Low Voltage Directive) Standards: EN 60 950

In this document and the Hardware User Guide, Software User Guide all the information you may

need for developing a product meeting the R&TTE Directive is included.

The GE864-AUTO module is conform with the following US Directives:

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

• EMC (Electromagnetic Compatibility). Standards: FCC47 Part 15

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

- 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 3 dBi 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.

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13 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.

The European Community provides some Directives for the electronic equipments introduced on the

market. All the relevant information’s are 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 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

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14 Document Change Log

ISSUE#0 20/06/08 Release First ISSUE# 0

Telit Communications S p A GE864QA Quad-band GPRS Cell Module / GE864-QUAD Automotive User Manual GE864 Harware User Guide

Telit Communications S.p.A. Quad-band GPRS Cell Module / GE864-QUAD Automotive GE864 Harware User Guide

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