Telit Communications S p A GC864Q2 Quadband GSM/ GPRS Module User Manual GC864 Hardware User Guide

Telit Communications S.p.A. Quadband GSM/ GPRS Module GC864 Hardware User Guide

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GC864Q2 User Manual HTML Version

User Manual

GC864 QUAD V2

and

GC864 DUAL V2

Hardware User Guide

1vv0300874 Rev.0 – 2010-01-25

GC864 Hardware User Guide

1vv0300874 Rev.0 – 2010-01-25

APPLICABILITY TABLE

PRODUCT

GC864-QUAD V2

GC864-DUAL V2

GC864-QUAD V2 with SH

GC864 Hardware User Guide

1vv0300874 Rev.0 – 2010-01-25

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 document.

as well as utilization of its contents and communication thereof to others without

express authorization are prohibited. Offenders will be held liable for payment of

damages. All rights are reserved.

GC864 Hardware User Guide

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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. GC864 MECHANICAL DIMENSIONS ................................................................................................ 11

3.1. MECHANICAL VIEW OF TELIT GC864-QUAD V2 WITH SIM HOLDER .................................................................12

4. GC864-QUAD V2 / GC864-DUAL V2 MODULE CONNECTIONS.......................................................... 13

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

4.1.1.

GC864-QUAD V2 / GC864-DUAL V2 Antenna Connector...............................................................16

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

5.1. TURNING ON THE GC864-QUAD V2 / GC864-DUAL V2 ..............................................................................17

5.2. TURNING OFF THE GC864-QUAD V2 / GC864-DUAL V2.............................................................................19

5.2.1.

Hardware Unconditional Restart ..................................................................................................20

6. POWER SUPPLY............................................................................................................................. 22

6.1. POWER SUPPLY REQUIREMENTS ..................................................................................................................22

6.2. GENERAL DESIGN RULES ............................................................................................................................23

6.2.1.

Electrical Design Guidelines .........................................................................................................23

6.2.2.

Thermal Design Guidelines...........................................................................................................27

6.2.3.

Power Supply PCB Layout Guidelines...........................................................................................28

6.2.4.

Parameters for ATEX Applications................................................................................................29

7. ANTENNA ...................................................................................................................................... 31

7.1. GSM ANTENNA REQUIREMENTS ..................................................................................................................31

7.2. GSM ANTENNA – INSTALLATION GUIDELINES................................................................................................32

8. LOGIC LEVEL SPECIFICATIONS......................................................................................................33

8.1. RESET SIGNAL...........................................................................................................................................34

9. SERIAL PORTS ............................................................................................................................... 35

9.1. MODEM SERIAL PORT ...........................................................................................................................35

9.2. RS232 LEVEL TRANSLATION .......................................................................................................................37

9.3. 5V UART LEVEL TRANSLATION ...................................................................................................................39

10. AUDIO SECTION OVERVIEW ........................................................................................................ 41

10.1. SELECTION MODE.......................................................................................................................................41

10.2. ELECTRICAL CHARACTERISTICS....................................................................................................................43

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10.2.1.

Input Lines Characteristics ...........................................................................................................43

10.2.2.

Output Lines Characteristics.........................................................................................................44

11. GENERAL PURPOSE I/O .............................................................................................................46

11.1. GPIO LOGIC LEVELS ..................................................................................................................................47

11.2. USING A GPIO PAD AS INPUT ................................................................................................................48

11.3. USING A GPIO PAD AS OUTPUT .............................................................................................................48

11.4. USING THE RF TRANSMISSION CONTROL GPIO4 .......................................................................................48

11.5. USING THE RFTXMON OUTPUT GPIO5 ...................................................................................................48

11.6. USING THE ALARM OUTPUT GPIO6 ..............................................................................................................49

11.7. USING THE BUZZER OUTPUT GPIO7.........................................................................................................49

11.8. MAGNETIC BUZZER CONCEPTS ................................................................................................................50

11.8.1.

Short Description...........................................................................................................................50

11.8.1 Frequency Behavior ............................................................................................................................51

11.8.2.

Power Supply Influence.................................................................................................................51

11.8.3.

Warning..........................................................................................................................................51

11.8.4.

Working Current Influence............................................................................................................52

11.9. USING THE TEMPERATURE MONITOR FUNCTION.........................................................................................52

11.9.1.

Short Description...........................................................................................................................52

11.9.2.

Allowed GPIO .................................................................................................................................52

11.10. INDICATION OF NETWORK SERVICE AVAILABILITY........................................................................................53

11.11. RTC BYPASS OUT ..................................................................................................................................54

11.12. DAC CONVERTER ..................................................................................................................................55

11.12.1.

Description.................................................................................................................................55

11.12.2.

Enabling DAC.............................................................................................................................55

11.12.3.

Low Pass Filter Example...........................................................................................................56

11.13. ADC CONVERTER ..................................................................................................................................56

11.13.1.

Description.................................................................................................................................56

11.13.2.

Using ADC Converter.................................................................................................................57

12. ASSEMBLY THE GC864-QUAD V2 / GC864-DUAL V2 ON THE BOARD .......................................... 58

12.1.1.

Debug of the GC864-QUAD V2 / GC864-DUAL V2 in Production...................................................59

13. PACKING SYSTEM ...................................................................................................................... 60

14. CONFORMITY ASSESSMENT ISSUES .......................................................................................... 61

15. SAFETY RECOMMENDATIONS .................................................................................................... 63

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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 GC864-QUAD V2 / GC864-DUAL V2 module.

1.2. Audience

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

implement their applications using our GC864-QUAD V2 / GC864-DUAL V2 module.

1.3. Contact Information, Support

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

manuals, contact Telit Technical Support Center (TTSC) at:

TS-EMEA@telit.com

TS-NORTHAMERICA@telit.com

TS-LATINAMERICA@telit.com

TS-APAC@telit.com

Alternatively, use:

http://www.telit.com/en/products/technical-support-center/contact.php

For detailed information about where you can buy the Telit modules or for

recommendations on accessories and components visit:

http://www.telit.com

To register for product news and announcements or for product questions contact

Telit’s Technical Support Center (TTSC).

Our aim is to make this guide as helpful as possible. Keep us informed of your

comments and suggestions for improvements.

Telit appreciates feedback from the users of our information.

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1.4. Document Organization

This document contains the following chapters:

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

contact and support information, and text conventions.

Chapter 2: “Overview” provides an overview of the document.

Chapter 3: “GC864-QUAD V2 / GC864-DUAL V2 Mechanical Dimensions”

Chapter 4: “GC864-QUAD V2 / GC864-DUAL V2 Module Connections” deals with the

pin out configuration and layout.

Chapter 5: “Hardware Commands” How to control the module via hardware.

Chapter 6: “Power supply” Power supply requirements and general design rules.

Chapter 7: “Antenna” The antenna connection and board layout design are the most

important parts in the full product design

Chapter 8: “Logic Level specifications” Specific values adopted in the implementation

of logic levels for this module.

Chapter 9: “Serial ports” The serial port on the Telit GC864 is the core of the

interface between the module and OEM hardware

Chapter 10: “Audio Section overview” Refers to the audio blocks of the Base Band

Chip of the GC864 Telit Modules.

Chapter 11: “General Purpose I/O” How the general purpose I/O pads can be

configured.

Chapter 12 “DAC and ADC Section” Deals with these two kind of converters.

Chapter 13: “Mounting the GC864-QUAD V2 / GC864-DUAL V2 on the application

board” Recommendations and specifics on how to mount the module on the user’s

board.

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1.5. Text Conventions

Danger

–

This information MUST be followed or catastrophic equipment failure

or bodily injury may occur.

Caution or Warning

–

Alerts the user to important points about integrating the

module, if these points are not followed, the module and end user equipment

may fail or malfunction.

Tip or Information – Provides advice and suggestions that may be useful when

integrating the module.

All dates are in ISO 8601 format, i.e. YYYY-MM-DD.

1.6. Related Documents

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

• Audio settings application note , 80000NT10007a

• Digital voice Interface Application Note, 80000NT10004a

• Product description, 80331ST10074a

• SIM Holder Design Guides, 80000NT10001a

• AT Commands Reference Guide, 80000ST10025a

• Telit EVK2 User Guide, 1vv0300704

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1.7. Document History

ISSUE#0 2010-01-25 Release First ISSUE# 0

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2. Overview

In this document all the basic functions of a mobile phone are taken into account; for

each one of them a proper hardware solution is suggested and eventually the wrong

solutions and common errors to be avoided are 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 GC864-QUAD V2 / GC864-DUAL V2 module. For

further hardware details that may not be explained in this document refer to the Telit

GC864-QUAD V2 / GC864-DUAL V2 Product Description document where all the

hardware information is reported.

NOTICE:

(EN) The integration of the GSM/GPRS GC864-QUAD V2 / GC864-DUAL V2 cellular

module within user application shall be done according to the design rules described

in this manual.

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

However, no responsibility is assumed by Telit Communications S.p.A. for its use, or

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.

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3. GC864 Mechanical Dimensions

The Telit GC864-QUAD V2 / GC864-DUAL V2 module overall dimensions are:

• Length: 36.2 mm

• Width: 30 mm

• Thickness: 3.2 mm

• Weight: 4.8g

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3.1. Mechanical View of Telit GC864-QUAD V2 with SIM Holder

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4. GC864-QUAD V2 / GC864-DUAL V2 Module

Connections

4.1. PIN-OUT

The GC864-QUAD V2 / GC864-DUAL V2 uses a 80 pin Molex p.n. 53949-0878 male

connector for the connections with the external applications. This connector matches

the 54150-0878 models.

Pin Signal I/O Function Internal

Pull up Type

Power Supply

1 VBATT - Main power supply Power

2 VBATT - Main power supply Power

3 VBATT - Main power supply Power

4 VBATT - Main power supply Power

5 GND - Ground Power

6 GND - Ground Power

7 GND - Ground Power

Audio

8 AXE I Handsfree switching 100K

CMOS 2.8V

9 EAR_HF+ AO Handsfree ear output, phase + Audio

10 EAR_HF- AO Handsfree ear output, phase - Audio

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

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

13 MIC_HF+ AI Handsfree microphone input; phase Audio

14 MIC_HF- AI Handsfree microphone input; phase Audio

15 MIC_MT+ AI Handset microphone signal input; phase+ Audio

16 MIC_MT- AI Handset microphone signal input; phase- Audio

SIM Card Interface

181 SIMVCC - External SIM signal – Power supply for the SIM 1.8 / 3V

19 SIMRST O External SIM signal – Reset 1.8 / 3V

20 SIMIO I/O External SIM signal - Data I/O 1.8 / 3V

21 SIMIN I External SIM signal - Presence (active low) 47K

1.8 / 3V

22 SIMCLK O External SIM signal – Clock 1.8 / 3V

Trace

23 RX_TRACE I RX Data for debug monitor CMOS 2.8V

24 TX_TRACE O TX Data for debug monitor CMOS 2.8V

1 On this line a maximum of 10nF bypass capacitor is allowed

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Pin Signal I/O Function Internal

Pull up Type

47 SERVICE I

Servicepinshallbeusedtoupgradethe modulefromASC1(RX_TRACE,

TX_TRACE). Thepinshallbetiedlowtoenablethefeature onlyincaseofa

SWUpdateactivity.Itis required,fordebugpurpose,tobeconnected

toatestpadonthefinalapplication.

CMOS 2.8V

Prog. / Data + Hw Flow Control

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

26 C104/RXD O Serial data output (RXD) to DTE CMOS 2.8V

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

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

29 C108/DTR I Input for Data terminal ready signal (DTR) from DTE CMOS 2.8V

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

31 C105/RTS I Input for Request to send signal (RTS) from DTE CMOS 2.8V

32 C109/DCD O Output for Data carrier detect signal (DCD) to DTE CMOS 2.8V

DAC and ADC

37 ADC_IN1 AI Analog/Digital converter input A/D

38 ADC_IN2 AI Analog/Digital converter input A/D

39 ADC_IN3 AI Analog/Digital converter input A/D

40 DAC_OUT AO Digital/Analog converter output D/A

Miscellaneous Functions

45 STAT_LED O Status indicator led CMOS 1.8V

46 GND - Ground Ground

49 PWRMON O Power ON Monitor CMOS 2.8V

53 ON/OFF* I

Input command for switching power ON or OFF (toggle command). The

pulse to be sent to the GC864-QUAD V2 / GC864-DUAL V2 must be

equal or greater than 1 second.

47K

Pull up to VBATT

54 RESET* I Reset input

55 VRTC AO VRTC Backup capacitor Power

Telit GPIO / DVI

36 DVI_CLK - DVI_CLK (Digital Voice Interface Clock) CMOS 2.8V

59 TGPIO_04/TXCNTRL I/O Telit GPIO4 Configurable GPIO / RF Transmission Control CMOS 2.8V

63 TGPIO_10/DVI_TX I/O Telit GPIO10 Configurable GPIO / DVI_TX (Digital Voice Interface) CMOS 2.8V

65 DVI_RX I/O DVI_RX (Digital Voice Interface) CMOS 2.8V

66 TGPIO_03 I/O Telit GPIO3 Configurable GPIO CMOS 2.8V

67 TGPIO_08 I/O Telit GPIO8 Configurable GPIO CMOS 2.8V

68 TGPIO_06 / ALARM I/O Telit GPIO6 Configurable GPIO / ALARM CMOS 2.8V

70 TGPIO_01 I/O Telit GPIO1 Configurable GPIO CMOS 2.8V

71 DVI_WAO I/O DVI_WAO (Digital Voice Interface) CMOS 2.8V

73 TGPIO_07 / BUZZER I/O Telit GPIO7 Configurable GPIO / Buzzer CMOS 2.8V

74 TGPIO_02 / JDR I/O Telit GPIO02 I/O pin / Jammer detect report CMOS 2.8V

76 TGPIO_09 I/O Telit GPIO9 Configurable GPIO CMOS 2.8V

78 TGPIO_05/ RFTXMON I/O Telit GPIO05 Configurable GPIO / Transmitter ON monitor CMOS 2.8V

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Pin Signal I/O Function Internal

Pull up Type

RESERVED

17 Reserved -

33 Reserved -

34 Reserved -

35 Reserved -

41 Reserved -

42 Reserved -

43 Reserved -

44 Reserved -

48 Reserved -

50 Reserved -

51 Reserved -

52 Reserved -

56 Reserved -

57 Reserved -

58 Reserved -

60 Reserved -

61 Reserved -

62 Reserved -

64 Reserved -

69 Reserved -

72 Reserved -

75 Reserved -

77 Reserved -

79 Reserved -

80 Reserved -

NOTE:

The GC864-QUAD V2 / GC864-DUAL V2 Modules has one DVI ports on the system

interface.

NOTE:

Reserved pins must not be connected.

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NOTE:

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

NOTE:

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

following pins:

Pin Signal Function

1 VBATT Main power supply

2 VBATT Main power supply

3 VBATT Main power supply

4 VBATT Main power supply

5 GND Ground

6 GND Ground

7 GND Ground

46 GND Ground

25 C103/TXD Serial data input (TXD) from DTE

26 C104/RXD Serial data output to DTE

31 C105/RTS Input for Request to send signal (RTS) from DTE

53 ON/OFF* Input command for switching power ON or OFF (toggle command).

54 RESET* Reset input

23 RX_TRACE RX Data for debug monitor

24 TX_TRACE TX Data for debug monitor

47 SERVICE SERVICE connection

4.1.1. GC864-QUAD V2 / GC864-DUAL V2 Antenna Connector

The GC864-QUAD V2 / GC864-DUAL V2 module is equipped with a 50  RF connector

from Murata, GSC type P/N MM9329-2700B.

The counterpart suitable is Murata MXTK92 Type or MXTK88 Type.

Moreover, the GC864-QUAD V2 / GC864-DUAL V2 has the antenna pads on the back

side of the PCB. This allows the manual soldering of the coaxial cable directly on the

back side of the PCB. However, the soldering is not an advisable solution for a

reliable connection of the antenna.

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5. Hardware Commands

5.1. Turning ON the GC864-QUAD V2 / GC864-DUAL V2

To turn the GC864-QUAD V2 / GC864-DUAL V2 on, the pad ON# must be tied low for

at least 1000ms and then released. A pulse duration less than 1000ms should also

start the power on procedure, but this is not guaranteed.

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

A simple circuit to do it is:

TIP:

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

monitored. After 1000ms the line raised up the device could be considered powered

on.

NOTE:

Do not 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 GC864-QUAD V2 / GC864-DUAL V2

power regulator and improper power on/off of the module. The line ON# must be

connected only in open collector configuration.

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

labeled with a name that ends with a "#" or with a bar over the name.

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For example:

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

microcontroller (uP_OUT1):

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

A flow chart with proper turn on procedure is detailed below:

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5.2. Turning OFF the GC864-QUAD V2 / GC864-DUAL V2

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

• by software command (see GC864-QUAD V2 / GC864-DUAL V2 Software

User Guide)

• 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 GC864 via pin ON#, this must be tied

low for at least 1000ms 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# pin.

The following flow chart shows the proper turnoff procedure:

TIP:

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

monitored. When PWRMON goes low, then the device has powered off.

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5.2.1. 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 Restart the GC864-QUAD V2 / GC864-DUAL V2, the pad RESET#

must be tied low for at least 200 ms and then released.

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

A simple circuit to do it is:

NOTE:

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

Using pull up resistor may cause latch up problems on the GC864-QUAD V2 / GC864-

DUAL V2 power regulator and improper functioning of the module. The line RESET*

must be connected only in open collector configuration.

TIP:

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

the software must use it as an emergency exit procedure.

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

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):

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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 following requirements and guidelines for a proper design.

6.1. Power Supply Requirements

Condition Value

Nominal Supply Voltage 3.80 V

Normal operating Voltage Range 3.40 V - 4.20 V

Extended operating Voltage Range 3.22 V – 4.50 V

The GC864-QUAD V2 / GC864-DUAL V2 power consumptions are:

GE864-QUAD V2 / GE864-DUAL V2

Mode Average

(mA) Mode description

SWITCHED OFF

Switched Off <62 uA Module supplied but Switched Off

IDLE mode

AT+CFUN=1 19.0 Normal mode: full functionality of the module

AT+CFUN=4 18.0 Disabled TX and RX; module is not registered on the network

3.9 Paging Multiframe 2

2.9 Paging Multiframe 4

2.1 Paging Multiframe 6

1.9 Paging Multiframe 8

AT+CFUN=0 or =5

1.6 Paging Multiframe 9

CSD TX and RX mode

GSM900 CSD PL5 300

DCS1800 CSD PL0 200

GSM VOICE CALL

GPRS (class 10) 1TX

GSM900 PL5 260

DCS1800 PL0 170

GPRS Sending data mode

GPRS (class 10) 2TX

GSM900 PL5 470

DCS1800 PL0 300

GPRS Sending data mode

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The GSM system is made in a way that the RF transmission is not continuous but 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, then a strong noise floor is generated on

the ground and the supply; this will reflect on all the audio paths producing an

audible and 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 power supply must be designed so that it is capable of a peak current output of

at least 2 A.

6.2. 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.

6.2.1. 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

6.2.1.1. +5V input Source Power Supply Design Guidelines

• The desired output for the power supply is 3.8V, hence there is no big

difference between the input source and the desired output. 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.

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• A Bypass low ESR capacitor of adequate capacity must be provided in

order to cut the current absorption peaks close to the GC864-QUAD V2 /

GC864-DUAL V2, a 100F 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 can be inserted close to the power input, in order to

save the GC864-QUAD V2 / GC864-DUAL V2 from power polarity inversion.

An example of linear regulator with 5V input is:

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6.2.1.2. +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 GC864-QUAD V2 / GC864-DUAL V2.

• 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 that the switching frequency

could also generate EMC interferences.

• As far as car PB battery, the input voltage can rise up to 15.8V. This must

be kept in mind when choosing components: all components in the power

supply must withstand this voltage.

• A Bypass low ESR capacitor of adequate capacity must be provided, in

order to cut the current absorption peaks. A 100F tantalum capacitor is

typically used.

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

tantalum one) is rated at least 10V.

• As far as car applications, a spike protection diode must be inserted close

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

• A protection diode can be inserted close to the power input, in order to

save the GC864-QUAD V2 / GC864-DUAL V2 from power polarity inversion.

This can be the same diode used for spike protection.

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

parts):

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6.2.1.3. Battery Source Power Supply Design Guidelines

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

allowed is 4.5V. A single 3.7V Li-Ion cell battery type is suited for supplying the power

to the Telit GC864-QUAD V2 / GC864-DUAL V2 module.

CAUTION:

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 GC864-QUAD V2 / GC864-DUAL V2 and damage it.

CAUTION:

DO NOT USE any Ni-Cd, Ni-MH, and Pb battery types directly connected with GC864-

QUAD V2 / GC864-DUAL V2. Their use can lead to overvoltage on the GC864-QUAD V2

/ GC864-DUAL V2 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 100F tantalum capacitor is typically used.

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

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

GC864-QUAD V2 / GC864-DUAL V2 from power polarity inversion. Otherwise the

battery connector must be done in a way to avoid polarity inversions when connecting

the battery.

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

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

6.2.2. Thermal Design Guidelines

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

specifications:

• Average current consumption during transmission @PWR level max:

500mA

• Average current consumption during transmission @ PWR level min:

100mA

• Average current during Power Saving (CFUN=5): from 1.6 to 3.9mA

• Average current during idle (Power Saving disabled): 19mA

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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 us

say few minutes) and then remains for a quite long time in idle (let us 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, hence the current consumption will be less

than 500mA, 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 grants a good thermal condition to avoid

overheating as well.

As far as the heat generated by the GC864-QUAD V2 / GC864-DUAL V2, you can

consider it to be during transmissions of 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 GC864-

QUAD V2 / GC864-DUAL V2; you must ensure that your application can dissipate it.

6.2.3. 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 GC864-

QUAD V2 / GC864-DUAL V2 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 GC864-QUAD V2 /

GC864-DUAL V2 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.

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• 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 does not

have audio interface but only uses the data feature of the Telit GC864-

QUAD V2 / GC864-DUAL V2, then this noise is not so disturbing and power

supply layout design can be more forgiving.

• The PCB traces to the GC864-QUAD V2 / GC864-DUAL V2 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 must 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 must be kept separate from noise sensitive

lines such as microphone/earphone cables.

6.2.4. Parameters for ATEX Applications

In order to integrate the Telit GC864-QUAD V2 / GC864-DUAL V2 module into an ATEX

application, the appropriate reference standard IEC EN xx and integrations shall be

followed.

Below are listed parameters and useful information to integrate the module in your

application:

• Total capacity: 27.45 uF

• Total inductance: 55.20 nH

• No voltage upper than supply voltage is present in the module.

• No step-up converters are present in the module.

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• In abnormal conditions, the maximum RF output power may be up to 34

dBm.

For this particular application, we recommend the customer to involve TTSC (Telit

Technical Support Center) in the design phase of the application.

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7. 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.

7.1. GSM Antenna Requirements

As suggested on the Product Description the antenna for a Telit GC864-QUAD V2 /

GC864-DUAL V2 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

for GC864-QUAD V2

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

in DCS and 140 MHz PCS band

Bandwidth

for GC864-DUAL V2

80 MHz in GSM900 and 170 MHz in DCS

Gain Gain < 3dBi

Impedance 50 

Input power > 2 W peak power

VSWR absolute max <= 10:1

VSWR recommended <= 2:1

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 GC864-

QUAD V2 / GC864-DUAL V2 module. Antennas used for this OEM module must not

exceed 3dBi gain for mobile and fixed operating configurations.

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7.2. 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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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 Telit

GC864-QUAD V2 / GC864-DUAL V2 interface circuits:

Absolute Maximum Ratings – Not Functional

Parameter Min Max

Input level on any

digital pin when on

-0.3V +3.1V

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 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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8.1. Reset Signal

Signal Function I/O PIN Number

RESET Reset I 54

RESET is used to reset the GC864-QUAD V2 / GC864-DUAL V2 modules. Whenever

this signal is pulled low, the GC864-QUAD V2 / GC864-DUAL V2 is reset. When the

device is reset it stops any operation. After the release of the reset GC864-QUAD V2 /

GC864-DUAL V2 is unconditionally shut down, without doing any detach operation

from the network where it is registered. This behavior 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 is 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 GC864-QUAD V2 / GC864-DUAL V2. 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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9. Serial Ports

The serial port on the Telit GC864-QUAD V2 / GC864-DUAL V2 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 (TRACE for debug)

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 does not need a

level translation is the 2.8V UART.

The serial port on the GC864-QUAD V2 / GC864-DUAL V2 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 GC864-QUAD V2 / GC864-DUAL V2 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 +3.0 V

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Operating Range – Interface levels (2.8V CMOS)

Level Min Max

Input high level VIH 2.1V 3.1V

Input low level VIL 0V 0.5V

Output high level VOH 2.2V 3.0V

Output low level VOL 0V 0.35V

The table below shows the signals of the GC864-QUAD V2 / GC864-DUAL V2 serial

port:

RS232 Pin

Number

Signal GC864-

QUAD V2 /

GC864-

DUAL V2

Pad

Number

Name Usage

1 DCD –

dcd_uart 32 Data Carrier Detect Output from the GC864-QUAD V2 / GC864-DUAL V2

that indicates the carrier presence

2 RXD –

tx_uart 26 Transmit line *see Note Output transmit line of GC864-QUAD V2 / GC864-

DUAL V2 UART

3 TXD –

rx_uart 25 Receive line *see Note Input receive of the GC864-QUAD V2 / GC864-DUAL

V2 UART

4 DTR –

dtr_uart 29 Data Terminal Ready Input to the GC864-QUAD V2 / GC864-DUAL V2 that

controls the DTE READY condition

5 GND 5,6,7 Ground ground

6 DSR –

dsr_uart 27 Data Set Ready Output from the GC864-QUAD V2 / GC864-DUAL V2

that indicates the module is ready

7 RTS –

rts_uart 31 Request to Send Input to the GC864-QUAD V2 / GC864-DUAL V2 that

controls the Hardware flow control

8 CTS –

cts_uart 28 Clear to Send Output from the GC864-QUAD V2 / GC864-DUAL V2

that controls the Hardware flow control

9 RI – ri_uart 30 Ring Indicator Output from the GC864-QUAD V2 / GC864-DUAL V2

that indicates the incoming call condition

*NOTE:

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

on the GC864-QUAD V2 / GC864-DUAL V2 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 GC864-QUAD V2 / GC864-DUAL V2 serial port and vice

versa for RX.

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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.

9.2. RS232 Level Translation

In order to interface the Telit GC864-QUAD V2 / GC864-DUAL V2 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 3,1V; 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.

GC864-QUAD V2 / GC864-DUAL V2 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.

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NOTE:

In order to be able to do in circuit reprogramming of the GC864-QUAD V2 / GC864-

DUAL V2 firmware, the serial port on the Telit GC864-QUAD V2 / GC864-DUAL V2

shall be available for translation into RS232 and either it is controlling device shall be

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

reprogramming occurs.

Only RXD, TXD, GND, SERVICE 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 GC864.

An example of level translation circuitry of this kind is:

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

following layout:

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:

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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 GC864-QUAD V2 / GC864-DUAL V2 is NOT

internally pulled up with a resistor, so there may be the need to place an external

47K 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 47K may be required.

Care must be taken to avoid latch-up on the GC864-QUAD V2 / GC864-DUAL V2 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 GC864-

QUAD V2 / GC864-DUAL V2 functionality.

NOTE:

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 level

translator.

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10. Audio Section Overview

The first Baseband chip was developed for the cellular phones, which needed two

separated amplifiers both in RX and in TX section.

A couple of amplifiers had to be used with internal audio transducers while the other

couple of amplifiers had to be used with external audio transducers.

To distinguish the schematic signals and the Software identifiers, two different

definitions were introduced, with the following meaning:

• internal audio transducers Æ

HS/MT

(from

HandSet

MicroTelephone

)

• external audio transducers Æ

(from HandsFree )

Actually the acronyms have not the original importance.

In other words this distinction is not necessary, being the performances between the

two blocks like the same.

Only if the customer needs higher output power to drive the speaker, he needs to

adopt the Aduio2 Section (

) . Otherwise the choice could be done in order to

overcome the PCB design difficulties.

For these reasons we have not changed the

and

acronyms, keeping them in

the Software and on the schematics.

The Base Band Chip of the GC864-QUAD V2 / GC864-DUAL V2Telit Modules maintains

the same architecture.

For more information and suggestions refer to Telit document:

• Audio settings application note , 80000NT10007a

10.1. Selection mode

Only one block can be active at a time, and the activation of the requested audio

path is done via hardware ,by

AXE

line, or via software ,by

AT#CAP

command .

Moreover the

Sidetone

functionality could be implemented by the amplifier fitted

between the transmit path and the receive path, enabled at request in both modes.

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MIC N 2

100nF

Single ended

Balanced

Single ended

Bias

MIC P2

100nF

Single ended

Balanced

xgaffull.skd

Ear MT+

Ear MT-

MIC P1

MIC N 1

Mic MT-

Mic MT+

Ear HF+

Mic HF+

Mic HF-

LOUD1

Ear HF-

LOUD2

Earpiece

Speaker

Fully Differential

Audio Amplifier

Fully Differential

Audio Amplifier

Microphone

AUDIO 2

SECTION

AUDIO 1

SECTION

Baseband

Audio Front End

EP P1

EP N1

Single ended

Bias

Balanced

GE864-QUAD V2 / GE864-DUAL V2 Audio Front End Block Diagram

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10.2. 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 its particular application.

10.2.1. Input Lines Characteristics

“MIC_MT” and “MIC_HF” differential microphone paths

Line Coupling AC*

Line Type Balanced

Differential input voltage  1,03Vpp @

Mic G=0dB

Gain steps 7

Gain increment 6dB per step

Coupling capacitor  100nF

Differential input resistance 50K

Input capacitance • 10pF

(*) 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 100nF capacitor. Don’t forget that the useful input signal will be

halved in

Single Ended

Input

configuration.

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10.2.2. Output Lines Characteristics

TIP:

We suggest driving the load differentially from both output drivers, thus the output

swing will double and the need for the output coupling capacitor avoided. However if

particular OEM application needs also a

Single Ended 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 and to get the maximum power output from the

device (low resistance tracks).

WARNING:

The loads are directly connected to the amplifier outputs when in

Differential

configuration, through a capacitor when in

Single Ended

configuration.

Using a

Single Ended configuration

, the unused output line must be left open .

Not respecting this constraint, the output stage will be damaged.

TIP :

Remember that there are slightly different electrical performances between the two

internal audio amplifiers:

• the

“Ear_MT”

lines

can directly drive a

Ω

load

at –12dBFS (**) in

Differential

configuration

• the “

Ear_HF”

lines can directly drive a

Ω

load

Differential

configurations

• There is no difference if the amplifiers drive an external amplifier

(**)

0dBFS

is the normalized overall Analog Gain for each Output channel equal to

3,7V

differential

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“EAR_MT” Output Lines

line coupling

AC single-ended

DC differential

0dBFS normalized gain 3,7 Vpp differential

output load resistance  16 

@ -12dBFS

internal output resistance 4 (

typical

)

signal bandwidth 150 - 4000 Hz @ -3 dB

maximal full scale

differential output voltage

3,7 Vpp

(

typical

)

Rload=

open circuit

differential output voltage 925mVpp / Rload=16

@ -12dBFS

volume increment 2 dB per step

volume steps 10

“EAR_HF” Output Lines

line coupling

AC single-ended

DC differential

output load resistance  8 

signal bandwidth 150 - 4000 Hz @ -3 dB

maximal output power

@ battery voltage  3,6V

0.35 Wrms /8 

volume increment 2 dB per step

volume steps 10

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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 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 GC864-QUAD

V2 / GC864-DUAL V2 firmware and acts depending on the function implemented.

The following GPIO are available on the GC864-QUAD V2 / GC864-DUAL V2:

Pin Signal I/O Function Type Input / output

current

Default

state

ON_OFF

state

During

Reset

state

Note

70 TGPIO_01 I/O GPIO01

Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT 0 0

74 TGPIO_02 /

JDR I/O GPIO02

Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT 0 0

Alternate

function

(JDR)

66 TGPIO_03 I/O GPIO03

Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT 0 0

59 TGPIO_04 /

TXCNTRL I/O GPIO04

Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT 0 0

Alternate

function (RF

Transmission

Control)

78 TGPIO_05 /

RFTXMON I/O GPIO05

Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT 0 0

Alternate

function

(RFTXMON)

68 TGPIO_06 /

ALARM I/O GPIO06

Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT 0 0

Alternate

function

(ALARM)

73 TGPIO_07 /

BUZZER I/O GPIO07

Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT 0 0

Alternate

function

(BUZZER)

67 TGPIO_08 I/O GPIO08

Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT 0 0

76 TGPIO_09 I/O GPIO09

Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT 0 0

63 TGPIO_10 /

DVI_TX I/O GPIO10

Configurable GPIO CMOS 2.8V 1uA / 1mA INPUT 0 0

Alternate

function

(DVI_TX)

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Not all GPIO pads support all these three modes:

• GPIO2 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)

11.1. GPIO Logic Levels

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

levels.

The following tables show the logic level specifications used in the GC864-QUAD V2 /

GC864-DUAL V2 interface circuits:

Absolute Maximum Ratings –Not Functional

Parameter Min Max

Input level on any

digital pin when on

-0.3V +3.1V

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 0V 0.5V

Output high level 2.2V 3.0V

Output low level 0V 0.35V

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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, this pull up must be switched off when

the module is in off condition.

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.

The illustration below shows the base circuit of a push-pull stage:

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 resistor 47K pull up to 2.8V, this pull up must be

switched off when the module is in off condition.

11.5. Using the RFTXMON Output GPIO5

The GPIO5 pin, when configured as RFTXMON Output, is controlled by the GC864-

QUAD V2 / GC864-DUAL V2 module and will rise when the transmitter is active and

fall after the transmitter activity is completed.

VDD

GPIO7

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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.

11.6. Using the Alarm Output GPIO6

The GPIO6 pad, when configured as Alarm Output, is controlled by the GC864-QUAD

V2 / GC864-DUAL V2 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 GC864-QUAD V2 / GC864-DUAL V2

controlling micro controller 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 GC864-QUAD V2 / GC864-DUAL V2

during sleep periods, dramatically reducing the sleep consumption to few A.

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.

11.7. Using the Buzzer Output GPIO7

Alternate Function

, the GPIO7 is controlled by the firmware that depends on the

function implemented internally.

This setup places always the GPIO7 pin in

OUTPUT

direction and the corresponding

function must be activated properly by AT#SRP command (refer to

AT commands

specification

Also in this case, the

dummy value

for the pin state can be both “

” or “

”.

• Send the command AT#GPIO=7, 1, 2<cr>:

• Wait for response OK

• Send the command AT#SRP=3

The GPIO7 pin will be set as

Alternate Function

pin with its

dummy

logic status set to

HIGH

value.

The “

Alternate Function

” permits your application to easily implement Buzzer

feature with some small hardware extension of your application as shown in the

sample figure below.

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Example of Buzzer

’

s driving circuit

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.

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

TR1

BCR141W

TR2

SMBT2907A

4,7K

D1N4148

33pF

+V b u zze r

GPIO7

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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

11.8.1 Frequency Behavior

The frequency behavior represents the effectiveness of the reproduction of the

applied signals.

Because its performance is related to a square driving waveform (whose amplitude

varies from 0V to Vpp), if you modify the waveform (e.g. from square to sinus) the

frequency response will change.

11.8.2. Power Supply Influence

Applying a signal whose amplitude is different from that suggested by manufacturer,

the performance change following the rule:

if resonance frequency

o increases, amplitude decreases.

Because of resonance frequency depends from acoustic design, lowering the

amplitude of the driving signal the response bandwidth tends to become narrow, and

vice versa.

Summarizing: Vpp  Æ

o  Vpp  Æ

o 

The risk is that the

o could easily fall outside of new bandwidth; consequently the

SPL could be much lower than the expected.

11.8.3. Warning

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

“

a voltage more positive than the “

”

. If this happens, the diaphragm vibrates

in the opposite sense with a high probability to be expelled from its physical position,

damaging the device forever.

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11.8.4. Working Current Influence

In the component data sheet you will find the value of MAX CURRENT that 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.

11.9. Using the Temperature Monitor Function

11.9.1. Short Description

The Temperature Monitor is a function of the module that permits to control its

internal temperature and if properly set (see the #TEMPMON command on AT

Interface guide) it raise to High Logic level a GPIO when the maximum temperature

is reached.

11.9.2. Allowed GPIO

The AT#TEMPMON set command could be used with one of the following GPIO:

Signal Function Type

Input /

output

current

Note

TGPIO_01 GPIO01 Configurable GPIO CMOS 2.8V 1A / 1mA

TGPIO_03 GPIO03 Configurable GPIO CMOS 2.8V 1A / 1mA

TGPIO_08 GPIO08 Configurable GPIO CMOS 2.8V 1A / 1mA

TGPIO_09 GPIO09 Configurable GPIO CMOS 2.8V 1A / 1mA

TGPIO_10 GPIO10 Configurable GPIO CMOS 2.8V 1A / 1mA

The set command could be used also with one of the following GPIO but in that case the alternate

function is not usable:

Signal Function Type

Input /

output

current

Note

TGPIO_02 GPIO02 Configurable GPIO CMOS 2.8V 1A / 1mA Alternate function (JDR)

TGPIO_04 GPIO04 Configurable GPIO CMOS 2.8V 1A / 1mA Alternate function (RF

Transmission Control)

TGPIO_05 GPIO05 Configurable GPIO CMOS 2.8V 1A / 1mA Alternate function (RFTXMON)

TGPIO_07 GPIO07 Configurable GPIO CMOS 2.8V 1A / 1mA Alternate function (BUZZER)

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11.10. Indication of Network Service Availability

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

status.

In the GC864-QUAD V2 / GC864-DUAL V2 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:

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11.11. 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.

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11.12. DAC Converter

11.12.1. Description

Pin Signal I/O Function Internal

Pull up Type

DAC Converter

40 DAC_OUT AO Digital/Analog converter output D/A

The GC864-QUAD V2 / GC864-DUAL V2 module provides one Digital to Analog

Converter.

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) 0 2,6 Volt

Range 0 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.

11.12.2. Enabling DAC

The AT command below is available to use the DAC function:

AT#DAC[=<enable>[,<value>]]

<value> – scale factor of the integrated output voltage (0–1023, with 10 bit precision),

and it must be present if <enable>=1.

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

this function.

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

this function.

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NOTE:

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

POWERSAVING.

11.12.3. Low Pass Filter Example

11.13. ADC Converter

11.13.1. Description

Pin Signal I/O Function Internal

Pull up Type

ADC Converters

37 ADC_IN1 AI Analog/Digital converter input A/D

38 ADC_IN2 AI Analog/Digital converter input A/D

39 ADC_IN3 AI Analog/Digital converter input A/D

The GC864-QUAD V2 / GC864-DUAL V2 module provides three Analog to Digital

Converter.

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 0 2 Volt

AD conversion - 11 bits

Resolution - < 1 mV

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11.13.2. Using ADC Converter

The AT command below is available to use the ADC function:

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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12. Assembly the GC864-QUAD V2 / GC864-DUAL V2 on

the Board

The position of the Molex board to board connector and the pin 1 are shown in the

following picture.

NOTE:

The metal tabs present on GC864-QUAD V2 / GC864-DUAL V2 must be connected to

GND.

This module could not be processed with a reflow.

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12.1.1. Debug of the GC864-QUAD V2 / GC864-DUAL V2 in Production

To test and debug the mounting of the GC864, we strongly recommend to foreseen

test pads on the host PCB, in order to check the connection between the GC864-

QUAD V2 / GC864-DUAL V2 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:

Pin Signal I/O Function Internal

Pull up Type

ADC Converters

5,6,7,

GND - Ground Ground

1,2,3,4 VBATT - Main power supply Power

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

26 C104/RXD O Serial data output (RXD) to DTE CMOS 2.8V

53 ON/OFF* I Input command for switching power ON or

OFF (toggle command). The pulse to be sent

to the GC864-QUAD V2 / GC864-DUAL V2 must

be equal or greater than 1 second.

47K

Pull up to

VBATT

54 RESET* I Reset input

49 PWRMON O Power ON Monitor CMOS 2.8V

23 RX_TRACE I RX Data for debug monitor CMOS 2.8V

24 TX_TRACE O TX Data for debug monitor CMOS 2.8V

47 SERVICE I SERVICE connection CMOS 2.8V

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13. Packing System

The Telit GC864-QUAD V2 / GC864-DUAL V2 are packaged on trays of 20 pieces

each.

The size of the tray is: 329 x 176mm.

WARNING:

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

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14. Conformity Assessment Issues

The Telit GC864-QUAD V2 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 harmonized 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 contains all the information you may need for developing a

product meeting the R&TTE Directive.

Furthermore the GC864-QUAD V2 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 GC864-QUAD V2 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:

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• 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.

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15. SAFETY RECOMMENDATIONS

NOTE:

Read this section carefully to ensure the safe operation.

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 EN 50360.

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The European Community provides some Directives for the electronic equipments

introduced on the market. All the relevant information 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

Telit Communications S p A GC864Q2 Quadband GSM/ GPRS Module User Manual GC864 Hardware User Guide

Telit Communications S.p.A. Quadband GSM/ GPRS Module GC864 Hardware User Guide

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