Wavecom Wireless CPU Q24NG Instruction Manual

WM_
Wireless CPU Q24NG
Customer Design Guideline
Revision: 001
Date: June 2006

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WM_PRJ_Q24NG_PTS_002-001 June 2006
Wireless CPU Q24NG
Customer Design Guideline
Reference: WM_PRJ_Q24NG_PTS_002
Revision: 001
Date: June 2006
Powered by the Wavecom Operating System and Open AT®

Wireless CPU Q24NG - Customer Design Guideline
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Document Information
Level Date History of the evolution
001 04/05/2006 Creation (Preliminary version)

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Overview
This document gives recommendations for Wireless CPU Q24NG sub-
series integration in an application and particularly:
• The baseband design rules and typical implementation examples,
• The RF design rules and typical implementation examples
• The mechanical constraints for module fitting,
• The PCB routing recommendations,
• The Test and download recommendations.
It also gives some part references and suppliers.
The Q24NG is available under 4 versions of GSM/GPRS Class 10 quad-
band versions:
• Q24 Classic: EGSM 900/1800/850/1900 MHz version with 32 Mb of
Flash memory and 16 Mb of PSRAM (32/16), T° range [-20°C / +55°C]-
Full ETSI specification-
• Q24 Plus: EGSM/GPRS 900/1800/850/1900 MHz version with 32 Mb of
Flash memory and 16 Mb of PSRAM (32/16) T° range [-20°C / +55°C] -
Full ETSI specification-
• Q24 Extended: EGSM/GPRS 900/1800/850/1900 MHz version with 32
Mb of Flash memory and 4Mb of SRAM (32/4) extended T° range [-
40°C / +85°C]
• Q24 Automotive: EGSM/GPRS 900/1800/850/1900 MHz version with
32 Mb of Flash memory and 4Mb of PSRAM (32/4) extended T° range
[-40°C / +85°C]
o This version is dedicated to automotive applications.
Please be aware that some of the interfaces provided by the Wireless
CPU Q24NG sub-series cannot be handled when using the module driven
by AT commands.
This symbol is used to indicate the interfaces not available with
AT commands.
AAA
TTT
These functions then have to be managed externally i.e using the main
processor of the application.

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Contents
Document Information......................................................................... 2
Overview ............................................................................................. 3
Contents.............................................................................................. 4
Table of Figures................................................................................... 7
Cautions .............................................................................................. 9
Trademarks ......................................................................................... 9
Copyright ............................................................................................ 9
1References................................................................................ 10
1.1 References documents ......................................................................... 10
1.1.1 WAVECOM reference document ................................................... 10
1.1.2 General reference document ......................................................... 10
1.2 List of abbreviations ............................................................................. 11
2General description................................................................... 14
2.1 Overall dimensions ............................................................................... 14
2.2 Power consumption ............................................................................. 14
2.3 Capability ............................................................................................. 14
2.4 External RF connections ....................................................................... 14
2.5 SIM interface connections .................................................................... 15
2.6 RoHS compliance ................................................................................. 15
3Baseband Design ...................................................................... 16
3.1 Power supply and ground design rules................................................. 16
3.1.1 Electrical constraints ..................................................................... 16
3.1.2 Design Requirements.................................................................... 18
3.1.2.1 Risk......................................................................................... 18
3.1.2.2 General design rules ............................................................... 18
3.1.2.3 Battery integration ................................................................. 19
3.1.2.4 External DC power supply....................................................... 19
3.1.3 PCB routing constraints ................................................................ 20

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3.1.3.1 Power supply routing Constraints........................................... 20
3.1.3.2 Application ground plane and shielding connection ................ 20
3.1.3.3 Decoupling of power supply signals ....................................... 20
3.2 Digital I/O and peripheral implementation ............................................. 21
3.2.1 Electrical information for digital I/O ............................................... 21
3.2.2 LCD interface ................................................................................ 21
3.2.2.1 SPI bus ................................................................................... 21
3.2.2.2 I2C........................................................................................... 22
3.2.3 SPI Auxiliary bus........................................................................... 22
3.2.4 Keyboard interface ........................................................................ 22
3.2.5 Main serial link (UART1) ............................................................... 23
3.2.6 SIM interface ................................................................................ 26
3.2.6.1 SIM 3V management .............................................................. 26
3.2.6.2 SIM 1.8 V / 3 V management .................................................. 28
3.2.6.3 SIM 3 V / 5 V management ..................................................... 29
3.3 Analog I/O implementation ................................................................... 30
3.3.1 Analog to Digital Converter (ADC) inputs ...................................... 30
3.3.2 Audio interface.............................................................................. 31
3.3.2.1 Microphone inputs.................................................................. 31
3.3.2.1.1 General ................................................................................. 31
3.3.2.1.2 Recommended characteristics for the microphones .............. 31
3.3.2.1.3 Main Microphone Inputs (MIC2) ........................................... 32
3.3.2.1.4 Auxiliary Microphone Inputs (MIC1)...................................... 32
3.3.2.2 Speaker outputs...................................................................... 35
3.3.2.2.1 Common speaker output characteristics ............................... 35
3.3.2.3 Buzzer Output......................................................................... 36
3.3.2.4 Routing constraints................................................................. 36
3.4 Battery charging interface..................................................................... 37
3.4.1 General information ...................................................................... 37
3.4.2 Interface description ..................................................................... 37
3.5 ON / ~OFF ............................................................................................ 38
3.6 BOOT signal (optional).......................................................................... 39
3.7 Reset signal (~RST) .............................................................................. 40
3.8 External Interrupt (~INTR)..................................................................... 40
3.9 VCC output ........................................................................................... 41
3.10 VCC_RTC (Real Time Clock Supply) ....................................................... 41
3.10.1 General ......................................................................................... 41
3.10.2 Typical implementation................................................................. 42
3.10.2.1 Capacitor ................................................................................ 42
3.10.2.2 Super Capacitor ...................................................................... 42
3.10.2.3 Battery cell with regulator ....................................................... 43
3.10.2.4 .Non Rechargeable battery ...................................................... 43
4Radio design ............................................................................. 44
4.1 Antenna characteristics ........................................................................ 44
4.2 Antenna implementation ...................................................................... 44
4.2.1 Recommendations ........................................................................ 44
4.2.2 RF connection ............................................................................... 45

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5Mechanical specifications ........................................................ 47
6PCB design ............................................................................... 48
6.1 General design rules ............................................................................. 48
6.2 Design rules for application manufacturing........................................... 48
6.3 Recommendation for lead free soldering ............................................... 48
6.4 Power supply ....................................................................................... 48
6.5 Pads design.......................................................................................... 49
7EMC recommendations............................................................. 50
8Firmware upgrade..................................................................... 51
8.1 Recommendations ................................................................................ 51
8.2 Nominal upgrade procedure ................................................................. 51
8.3 Backup procedure................................................................................. 52
9Embedded testability ................................................................ 53
10 Part references and suppliers ................................................... 56
10.1 General Purpose Connector .................................................................. 56
10.2 SIM Card Reader .................................................................................. 56
10.3 Microphone .......................................................................................... 56
10.4 Speaker ................................................................................................ 57
10.5 Antenna Connections ........................................................................... 57
10.5.1 Antenna pad ................................................................................. 57
10.5.2 IMP connector (RF board to board) ............................................... 57
10.5.3 UFL connector............................................................................... 57
10.5.4 MMS connector ............................................................................ 58
10.6 GSM antenna ....................................................................................... 58

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Table of Figures
Figure 1: Typical power supply voltage in GSM mode ............................. 16
Figure 2: Maximal voltage ripple (Uripp) vs Frequency in GSM & DCS, To
be confirmed ...................................................................................... 18
Figure 3: Burst simulation circuit ............................................................. 19
Figure 4: Example of SPI Bus typical implementation .............................. 22
Figure 5: Example of keyboard implementation ....................................... 23
Figure 6: Example of RS232 level shifter implementation......................... 24
Figure 7: Example of Serial Link interface implementation ....................... 25
Figure 8: Example of 3V SIM Socket implementation............................... 26
Figure 9: 1.8 V / 3 V SIM interface implementation example .................... 28
Figure 10: 3 V / 5 V SIM interface implementation example ..................... 29
Figure 11: Example of ADC input implementation.................................... 30
Figure 12: Microphone decoupling capacitor ........................................... 31
Figure 13: Example of main microphone MIC2 implementation (differential
connection) ........................................................................................ 32
Figure 14: MIC1 inputs (differential connection) ...................................... 33
Figure 15: MIC1 inputs (single-ended connection)................................... 34
Figure 16: Speaker outputs (differential mode)......................................... 35
Figure 17: Speaker outputs (single-ended connection)............................. 35
Figure 18: Example of Buzzer implementation ......................................... 36
Figure 19: Example of battery implementation......................................... 37
Figure 20: BOOT pin connection.............................................................. 39
Figure 21: ∼RST pin connection ............................................................... 40
Figure 22: RTC Supplied by a capacitor ................................................... 42
Figure 23: RTC supplied by a super capacitor.......................................... 42
Figure 24: RTC supplied by a battery cell with regulator.......................... 43
Figure 25: RTC supplied by a non rechargeable battery ........................... 43
Figure 26: Antenna connection................................................................ 45
Figure 27: Antenna cable preparation (drawing not to scale) ................... 46
Figure 28: Maximum bulk occupied on the application board .................. 47

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Figure 29: Pads design ...................................................................... 49
Figure 30: Example of serial link routing for downloading........................ 53
Figure 31: Download cable schematics (1/2) ........................................... 54
Figure 32: Download cable schematics (2/2) ........................................... 55

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WM_PRJ_Q24NG_PTS_002-001 June 2006
Cautions
This platform contains a modular transmitter. This device is used for
wireless applications. Note that all electronics parts and elements are ESD
sensitive.
Information provided herein by WAVECOM is accurate and reliable.
However no responsibility is assumed for its use and any of such
WAVECOM information is herein provided “as is” without any warranty of
any kind, whether express or implied.
General information about WAVECOM and its range of products is
available at the following internet address: http://www.wavecom.com
Trademarks
®, WAVECOM®, Wireless CPU®, Open AT®and certain other trademarks
and logos appearing on this document, are filed or registered trademarks
of Wavecom S.A. in France or in other countries. All other companies
and/or product names mentioned may be filed or registered trademarks of
their respective owners.
Copyright
This manual is copyrighted by WAVECOM with all rights reserved. No part
of this manual may be reproduced in any form without the prior written
permission of WAVECOM. No patent liability is assumed with respect to
the use of their respective owners.

References
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1 References
1.1 References documents
For more details, several reference documents may be consulted. The
WAVECOM reference documents are provided in the WAVECOM
documents package contrary to the general reference documents which
are not WAVECOM owned.
1.1.1 WAVECOM reference document
[1] Automotive Environmental Control Plan for Wireless CPU Q24NG
WM_PRJ_Q24NG_DCP_001
[2] Environmental Control Plan for Wireless CPU Q24NG
WM_PRJ_Q24NG_DCP_002
[3] Wireless CPU Q24NG Product Technical Specification
WM_PRJ_Q24NG_PTS_001
[4] Wireless CPU Q24NG Process Customer Guidelines
WM_PRJ_Q24NG_PTS_003
[5] AT Commands Interface Guide for OS 6.57
TBD
1.1.2 General reference document
[6] “I²C Bus Specification”, Version 2.0, Philips Semiconductor 1998
[7] ISO 7816-3 Standard

References
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1.2 List of abbreviations
Abbreviation Definition
AC Alternating Current
ADC Analog to Digital Converter
A/D Analog to Digital conversion
AF Audio-Frequency
AT ATtention (prefix for modem commands)
AUX AUXiliary
CAN Controller Area Network
CB Cell Broadcast
CEP Circular Error Probable
CLK CLocK
CMOS Complementary Metal Oxide Semiconductor
CS Coding Scheme
CTS Clear To Send
DAC Digital to Analogue Converter
dB Decibel
DC Direct Current
DCD Data Carrier Detect
DCE Data Communication Equipment
DCS Digital Cellular System
DR Dynamic Range
DSR Data Set Ready
DTE Data Terminal Equipment
DTR Data Terminal Ready
EFR Enhanced Full Rate
E-GSM Extended GSM
EMC ElectroMagnetic Compatibility
EMI ElectroMagnetic Interference
EMS Enhanced Message Service
EN ENable
ESD ElectroStatic Discharges
FIFO First InFirst Out
FR Full Rate
FTA Full Type Approval
GND GrouND

References
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Abbreviation Definition
GPI General Purpose Input
GPC General Purpose Connector
GPIO General Purpose Input Output
GPO General Purpose Output
GPRS General Packet Radio Service
GPS Global Positioning System
GSM Global System for Mobile communications
HR Half Rate
I/O Input / Output
LED Light Emitting Diode
LNA Low Noise Amplifier
MAX MAXimum
MIC MICrophone
MIN MINimum
MMS Multimedia Message Service
MO Mobile Originated
MT Mobile Terminated
na Not Applicable
NF Noise Factor
NMEA National Marine Electronics Association
NOM NOMinal
NTC Négative Temperature Coefficient
PA Power Amplifier
Pa Pascal (for speaker sound pressure measurements)
PBCCH Packet Broadcast Control CHannel
PC Personal Computer
PCB Printed Circuit Board
PDA Personal Digital Assistant
PFM Power Frequency Modulation
PSM Phase Shift Modulation
PWM Pulse Width Modulation
RAM Random Access Memory
RF Radio Frequency
RFI Radio Frequency Interference
RHCP Right Hand Circular Polarization
RI Ring Indicator

References
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Abbreviation Definition
RST ReSeT
RTC Real Time Clock
RTCM Radio Technical Commission for Maritime services
RTS Request To Send
RX Receive
SCL Serial Clock
SDA Serial Data
SIM Subscriber Identification Wireless CPU
SMS Short Message Service
SPI Serial Peripheral Interface
SPL Sound Pressure Level
SPK SPeaKer
SRAM Static RAM
TBC To Be Confirmed
TDMA Time Division Multiple Access
TP Test Point
TVS Transient Voltage Suppressor
TX Transmit
TYP TYPical
UART Universal Asynchronous Receiver-Transmitter
USB Universal Serial Bus
USSD Unstructured Supplementary Services Data
VSWR Voltage Standing Wave Ratio

General description
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2 General description
2.1 Overall dimensions
• 58.4 x 32.2 x 3.9 mm.(thickness is 6,2 mn for Q24 Automotive
which offers MMS or UFL connector on top side)
2.2 Power consumption
• 2 Watts E-GSM 900/GSM 850 radio section running under 3.6
Volts.
• 1 Watt GSM1800/1900 radio section running under 3.6 Volts.
2.3 Capability
• Real Time Clock with calendar (RTC).
• Battery charge management.
• Echo Cancellation + noise reduction.
• Full GSM or GSM/GPRS software stack.
• Complete interfacing through a 60-pin connector:
o Power supply,
o Internal regulator for external application
(VCC=2V8,100mA)
o Serial link,
o Audio,
o 1V8/3V SIM card interfaces (for others SIM interfaces
adaptation -e.g. 3V/5V-, refer to the chapters § 3.2.6.2
and 3.2.6.3 ).
o Keyboard,
o LCD.
2.4 External RF connections
• Q24NG is available with different external RF connections
configurations:
Product
reference
UFL on bottom
side
UFL or MMS on
top side
Antenna pad on
top side
IMP on bottom
side
Q24 Classic X X X
Q24 Plus X X X
Q24
Extended X X X
Q24
Automotive X X X

General description
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2.5 SIM interface connections
• An optional SIM holder is offered on Q24 Plus and Q24
Extended.
SIM interface location
Product
reference GPC (60 pins connector) optional SIM holder
Q24 Classic X
Q24 Plus X X
Q24
Extended X X
Q24
Automotive X
Warning:
-When a SIM card is plugged into the SIM holder, SIM interface
through GPC connector must not be used.
Some ESD (0402 package) protections are added close to the SIM
holder.
 Mechanical design of the application must take into
account those protections.
Customers are advised to verify that the environmental
specification of the SIM Card used is compliant with the Wireless
CPU Q24NG environmental specifications ([3] Wireless CPU
Q24NG Product Technical Specification
WM_PRJ_Q24NG_PTS_001). Any application must be qualified by
the customer with the SIM Card in storage, transportation and
operation.
2.6 RoHS compliance
Wireless CPU Q24NG sub-series are compliant with RoHS (Restriction
of Hazardous Substances in Electrical and Electronic Equipment)
Directive 2002/95/EC which sets limits for the use of certain restricted
hazardous substances. This directive states that “from 1st July 2006,
new electrical and electronic equipment put on the market does not
contain lead, mercury, cadmium, hexavalent chromium,
polybrominated biphenyls (PBB) or polybrominated diphenyl ethers
(PBDE)”.
Wireless CPUs which are compliant with this
directive are identified by the RoHS logo on their
label.

Baseband Design
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3 Baseband Design
Note:
Some of the Wireless CPU Interface signals are multiplexed in order to limit
number of pins but this architecture implies some limitation.
For example:
-The SPI bus interface can be also used as an I2C bus interface
-The GPO3 can be used as a reference clock 32Khz generator
Warning:
All external signals must be inactive when the Wireless CPU is OFF to
avoid any damage when starting and allow the Wireless CPU to start
correctly.
3.1 Power supply and ground design rules
3.1.1 Electrical constraints
The power supply is one of the key issues in the design of a GSM terminal.
Due to the bursted emission in GSM / GPRS, the power supply must be
able to deliver high current peaks in a short time and assured that the
voltage delivered to the module always remains under the limits specified
in the table “Maximum voltage ripple (Uripp) vs Frequency in GSM & DCS”
hereafter, specially during burst while there is a drop of voltage (see Figure
1).
In communication mode, a GSM/GPRS class 2 terminal emits 577 µs radio
bursts every 4.615 ms.
In communication mode, a GPRS class 10 terminal emits 1154 µs radio
bursts every 4.615 ms.
Uripp Uripp
T = 4.615 ms
t = 577 µs
VBATT(1)
IBATT
(1) or VDD if connected to VBATT
Vmax
Vmin
Figure 1: Typical power supply voltage in GSM mode
Two different inputs are provided for the power supply:
• the first one, VBATT is used to supply the RF part,
• the second one, VDD is used to supply the baseband part.

Baseband Design
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The power supply voltage features given in the table hereafter will
guarantee nominal functioning of the module.
Power Supply Voltage
V
MIN VNOM VMAX
VBATT 3.3 V (*) 3.6 V 4.5 V (**)
VDD 3.1 V 4.5 V
Table 1: Power supply voltage
(*): This value has to be guaranteed during the burst (with 1.5 A Peak in
GSM or GPRS mode).
(**): max operating Voltage Stationary Wave Ratio (VSWR) 2:1.
When the wireless CPU is supplied with a battery, the total impedance
(battery+contacts+protections+PCB) should be < 150 mΩto limit voltage
drop-out within emission burst.
Warning:
As the radio power amplifier is directly connected to VBATT, the wireless
CPU is sensitive to any Alternating Current on lines.
When a DC/DC converter is used, Wavecom recommends setting the
converter frequency in such a way that the resulting voltage does not
exceed the values in the following table:
Freq.
(kHz)
Uripp Max
(mVpp)
Freq.
(kHz)
Uripp Max
(mVpp)
Freq.
(kHz)
Uripp Max
(mVpp)
<100 50 800 4 1500 34
200 15.5 900 15.2 1600 33
300 6.8 1000 9.5 1700 37
400 3.9 1100 32 1800 40
500 4 1200 22 >1900 40
600 2 1300 29
700 8.2 1400 30
Table 2: Maximum voltage ripple (Uripp) vs Frequency in GSM & DCS,
To Be Confirmed

Baseband Design
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0
5
10
15
20
25
30
35
40
45
50
200 400 600 800 1000 1200 1400 1600 1800
Input Frequency (kHz)
Uripp (mVpp)
for f<100kHz Uripp Max = 50mVpp
for f> 1800kHz Uripp Max = 40 mVpp
Figure 2: Maximal voltage ripple (Uripp) vs Frequency in GSM & DCS,
To be confirmed
3.1.2 Design Requirements
3.1.2.1 Risk
VBATT directly supplies the RF components with 3.6 V. It is essential to
keep a minimum voltage ripple at this connection in order to avoid any
phase error. Insufficient power supply voltage could dramatically affect
some RF performance factors:
• TX power of course and modulation spectrum,
• EMC performances (spurious emission),
• Emissions spectrum,
• Phase error and frequency error.
3.1.2.2 General design rules
Careful attention should be paid to:
• Quality of the power supply: capacity to deliver high peak current in
a short time (bursted radio emission), low ripple and low
impedance.
• The battery charger line must support 800 mA to comply with the
voltage level required for the product.
• The VBATT lines on the PCB must support peak currents with a
voltage drop below the specified limit.
In order to test the supply tracks, a burst simulation circuit is shown
hereafter. This circuit simulates burst emissions, equivalent to bursts
generated when transmitting at full power.

Baseband Design
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Figure 3: Burst simulation circuit
3.1.2.3 Battery integration
The Q24NG may be directly connected to a Li-Ion battery (3.7 V typical
voltage, with internal PCM – Protection Circuit Module). The internal
impedance of the battery must be lower than 150 mΩto limit voltage drop-
out within emission burst (max. drop 0.3 V @ 2W).
Battery internal impedance must take into account:
• the internal impedance of the battery cell,
• the protection circuit impedance,
• the “packaging” impedance (contacts),
• the PCB track impedance up to the Wireless CPU pin.
3.1.2.4 External DC power supply
The Q24NG may be connected to DC power supply directly or via a DC/DC
converter on the mother board. The internal impedance of the power
supply must be lower than 150 mΩto limit voltage drop-out within
emission burst (max. drop 0.3 V @ 2W).
This impedance must take into account:
• the internal impedance of the power supply,
• the protection circuit impedance,
• the “packaging” impedance (contacts),
• the PCB track impedance up to the Wireless CPU pin.
Linear regulation (recommended) or PWM (Pulse Width Modulation)
converter (usable) are preferred for low noise.
Warning:
PFM (Power Frequency Modulation) or PSM (Phase Shift Modulation)
systems must be avoided.