Quectel Wireless Solutions 201211M50 GSM/GPRS Module User Manual M10 Hardware Design

M50Hardware Design

M50_HD_V2.0 - 1 -

M50

Quectel Cellular Engine

Hardware Design

M50_HD_V2.0

M50Hardware Design

M50_HD_V2.0 - 2 -

Document Title M50 Hardware Design

Revision 2.0

Date 2012-06-26

Status Released

Document Control ID M50_HD_V2.0

General Notes

Quectel offers this information as a service to its customers, to support application and

engineering efforts that use the products designed by Quectel. The information provided is

based upon requirements specifically provided for customers of Quectel. Quectel has not

undertaken any independent search for additional information, relevant to any information

that may be in the customer’s possession. Furthermore, system validation of this product

designed by Quectel within a larger electronic system remains the responsibility of the

customer or the customer’s system integrator. All specifications supplied herein are subject to

change.

Copyright

This document contains proprietary technical information of Quectel Co., Ltd. Copying this

document, distribution to others, and communication of the contents thereof, are forbidden

without permission. Offenders are liable to the payment of damages. All rights are reserved in

the event of a patent grant or registration of a utility model or design. All specifications

supplied herein are subject to change without notice at any time.

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Contents

Contents ................................................................................................................................................... 3

Table Index .............................................................................................................................................. 5

Figure Index ............................................................................................................................................ 6

0. Revision history .................................................................................................................................. 8

1. Introduction ....................................................................................................................................... 9

1.1. Related documents.................................................................................................................... 9

1.2. Terms and abbreviations......................................................................................................... 10

1.3. Safety cautions ........................................................................................................................ 12

2. Product concept ............................................................................................................................. 15

2.1. Key features ............................................................................................................................ 15

2.2. Functional diagram ................................................................................................................. 17

2.3. Evaluation board ..................................................................................................................... 18

3. Application interface ...................................................................................................................... 19

3.1. Pin of module .......................................................................................................................... 20

3.1.1. Pin assignment .............................................................................................................. 20

3.1.2. Pin description .............................................................................................................. 22

3.2. Operating modes ..................................................................................................................... 29

3.3. Power supply........................................................................................................................... 30

3.3.1. Power features of module ............................................................................................ 30

3.3.2. Decrease supply voltage drop ...................................................................................... 30

3.3.3. Reference design for power supply ............................................................................. 31

3.3.4. Monitor power supply .................................................................................................. 32

3.4. Power on and down scenarios ................................................................................................ 32

3.4.1. Power on ....................................................................................................................... 32

3.4.2. Power down .................................................................................................................. 34

3.4.3. Restart ........................................................................................................................... 36

3.5. Charge interface ...................................................................................................................... 38

3.6. Power saving ........................................................................................................................... 38

3.6.1. Minimum functionality mode ...................................................................................... 38

3.6.2. SLEEP mode................................................................................................................. 39

3.6.3. Wake up module from SLEEP mode .......................................................................... 39

3.7. Summary of state transition ................................................................................................... 39

3.8. RTC backup............................................................................................................................. 40

3.9. Serial interfaces ...................................................................................................................... 41

3.9.1. UART Port .................................................................................................................... 42

3.9.2. Debug Port .................................................................................................................... 46

3.9.3. Auxiliary UART Port ................................................................................................... 46

3.9.4. UART application ........................................................................................................ 47

3.10. Audio interfaces .................................................................................................................... 50

3.10.1. Decrease TDD noise and other noise ........................................................................ 51

3.10.2. Microphone interfaces design.................................................................................... 51

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3.10.3. Receiver and speaker interface design ...................................................................... 52

3.10.4. Earphone interface design.......................................................................................... 54

3.10.5. Loud speaker interface design ................................................................................... 54

3.10.6. Audio characteristics .................................................................................................. 55

3.11. SIM card interface ................................................................................................................ 55

3.11.1. SIM card application .................................................................................................. 55

3.11.2. 6 Pin SIM cassette ...................................................................................................... 57

3.11.3. 8 Pin SIM cassette ...................................................................................................... 58

3.12. SD card interface .................................................................................................................. 60

3.13. PCM interface ....................................................................................................................... 62

3.13.1. Configuration .............................................................................................................. 62

3.13.2. Timing ......................................................................................................................... 63

3.13.3. Reference design ........................................................................................................ 64

3.13.4. AT command .............................................................................................................. 64

3.14. ADC ....................................................................................................................................... 66

3.15. Behaviors of the RI............................................................................................................... 66

3.16. Network status indication..................................................................................................... 69

3.17. Operating status indication .................................................................................................. 69

4. Antenna interface........................................................................................................................... 71

4.1. RF reference design ................................................................................................................ 71

4.2. RF output power ..................................................................................................................... 72

4.3. RF receiving sensitivity.......................................................................................................... 72

4.4. Operating frequencies............................................................................................................. 72

4.5. RF cable soldering .................................................................................................................. 73

5. Electrical, reliability and radio characteristics ......................................................................... 74

5.1. Absolute maximum ratings .................................................................................................... 74

5.2. Operating temperature ............................................................................................................ 74

5.3. Power supply ratings .............................................................................................................. 75

5.4. Current consumption .............................................................................................................. 76

5.5. Electro-static discharge .......................................................................................................... 78

6. Mechanical dimensions ................................................................................................................ 79

6.1. Mechanical dimensions of module ........................................................................................ 79

6.2. Recommended footprint without bottom centre pads .......................................................... 81

6.4. Top view of the module ......................................................................................................... 82

6.5. Bottom view of the module.................................................................................................... 83

7. Storage and manufacturing ......................................................................................................... 84

7.1. Storage ..................................................................................................................................... 84

7.2. Soldering ................................................................................................................................. 85

7.3. Packaging ................................................................................................................................ 86

Appendix A: GPRS coding schemes ............................................................................................. 87

Appendix B: GPRS multi-slot classes............................................................................................ 88

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Table Index

TABLE 1: RELATED DOCUMENTS ..................................................................................................... 9

TABLE 2: TERMS AND ABBREVIATIONS........................................................................................ 10

TABLE 3: MODULE KEY FEATURES ................................................................................................ 15

TABLE 4: CODING SCHEMES AND MAXIMUM NET D ATA R ATE S OV E R A IR INTERFACE .. 17

TABLE 5: M50 PIN ASSIGNMENT ..................................................................................................... 21

TABLE 6: PIN DESCRIPTION ............................................................................................................. 22

TABLE 7: OVERVIEW OF OPERATING MODES.............................................................................. 29

TABLE 8: PIN DEF INITION OF THE CHARGING ............................................................................ 38

TABLE 9: SUMMARY OF STATE TRANSITION ............................................................................... 39

TABLE 10: LOGIC LEVELS OF THE UART INTERFACES.............................................................. 42

TABLE 11: PIN DEFINITION OF THE UART INTERFACES ............................................................ 42

TABLE 12: PIN DEFINITION OF AUDIO INTERFACES .................................................................. 50

TABLE 13: AOUT3 OUTPUT CHARACTERISTICS .......................................................................... 51

TABLE 14: TYP ICAL ELECTRET MICROPHONE CHARACTERISTICS ....................................... 55

TABLE 15: TYP ICAL SP EAKER CHARACTERISTICS .................................................................... 55

TABLE 16: PIN DEFINITION OF THE SIM INTERFACE ................................................................. 56

TABLE 17: PIN DESCRIPTION OF AMPHENOL SIM CARD HOLDER ......................................... 58

TABLE 18: PIN DESCRIPTION OF MOLEX SIM CARD HOLDER ................................................. 59

TABLE 19: PIN DEFINITION OF THE SD CARD INTERFACE ....................................................... 60

TABLE 20: PIN NAME OF THE SD CARD AND MICRO SD CARD ............................................... 61

TABLE 21: PIN DEFINITION OF PCM INTERFACE......................................................................... 62

TABLE 22: CONFIGURATION ............................................................................................................ 62

TABLE 23: QPCMON COMMAND DESCRIPTION .......................................................................... 65

TABLE 24: QPCMVOL COMMAND DESCRIPTION ........................................................................ 65

TABLE 25: PIN DEFINITION OF THE ADC....................................................................................... 66

TABLE 26: CHAR ACTERISTICS OF THE ADC ................................................................................ 66

TABLE 27: BEHAVIORS OF THE RI .................................................................................................. 66

TABLE 28: WOR KING STATE OF THE NETLIGHT ......................................................................... 69

TABLE 29: PIN DEFINITION OF THE STATUS................................................................................. 69

TABLE 30: PIN DEFINITION OF THE RF_ANT ................................................................................ 71

TABLE 31: THE MODULE CONDUCTED RF OUTPUT POWER .................................................... 72

TABLE 32: THE MODULE CONDUCTED RF RECEIVING SENSITIVITY .................................... 72

TABLE 33: THE MODULE OPERATING FREQUENCIES ................................................................ 72

TABLE 34: ABSOLUTE MAXIMUM RATINGS................................................................................. 74

TABLE 35: OPERATING TEMPERATURE ......................................................................................... 74

TABLE 36: THE MODULE POWER SUPPLY RATINGS ................................................................... 75

TABLE 37: THE MODULE CURRENT CONSUMPTION .................................................................. 76

TABLE 38: THE ESD ENDURANCE (TEMPERATURE:25℃,HUMIDITY:45 %)............................ 78

TABLE 39: DESCRIPTION OF DIFFERENT CODING SCHEMES .................................................. 87

TABLE 40: GPRS MULTI-SLOT CLASSES ........................................................................................ 88

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Figure Index

FIGURE 1: MODULE FUNCTIONAL DIAGRAM ............................................................................. 18

FIGURE 2: PIN ASSIGNMENT ............................................................................................................ 20

FIGURE 3: VOLTAGE RIPPLE DURING TRANSMITTING ............................................................. 30

FIGURE 4: REFERENCE CIRCUIT FOR THE VBAT INPUT ............................................................ 31

FIGURE 5: REFERENCE CIRCUIT FOR POWER SUPPLY .............................................................. 31

FIGURE 6: TURN ON THE MODULE USING DRIVING CIRCUIT................................................. 32

FIGURE 7: TURN ON THE MODULE USING KEYSTROKE ........................................................... 33

FIGURE 8: TIMING OF TURNING ON SYSTEM .............................................................................. 33

FIGURE 9: TIMING OF TURNING OFF THE MODULE................................................................... 34

FIGURE 10: REFERENCE CIRCUIT FOR EMERG_OFF BY USING DRIVING CIRCUIT ............ 36

FIGURE 11: REFERENCE CIRCUIT FOR EMERG_OFF BY USING BUTTON .............................. 36

FIGURE 12: TIMING OF RESTARTING SYSTEM ............................................................................ 37

FIGURE 13: TIMING OF RESTARTING S YSTEM AFTER EMERGENCY SHUTDOWN .............. 37

FIGURE 14: RTC SUPPLY FROM NON-CHARGEABLE BATTERY ............................................... 40

FIGURE 15: RTC SUPPLY FROM RECHARGEABLE BATTERY .................................................... 40

FIGURE 16: RTC SUPPLY FROM CAPACITOR ................................................................................ 40

FIGURE 17: SEIKO XH414H-IV01E CHARGE CHARACTER ISTICS ............................................. 41

FIGURE 18: REFERENCE DESIGN FOR FULL-FUNCTION UART ................................................ 44

FIGURE 19: REFERENCE DESIGN FOR UART PORT ..................................................................... 44

FIGURE 20: REFERENCE DESIGN FOR UART PORT WITH HARDWARE FLOW CONTROL... 45

FIGURE 21: REFERENCE DESIGN FOR FIRMWARE UPGRADE .................................................. 45

FIGURE 22: REFERENCE DESIGN FOR DEBUG PORT .................................................................. 46

FIGURE 23: REFERENCE DESIGN FOR AUXILIARY UART PORT ............................................... 47

FIGURE 24: LEVEL MATCH DESIGN FOR 3.3V SYSTEM.............................................................. 47

FIGURE 25: LEVEL MATCH DESIGN FOR 5V SYSTEM................................................................. 48

FIGURE 26: LEVEL MATCH DESIGN FOR RS-232 .......................................................................... 49

FIGURE 27: REFERENCE DESIGN FOR AIN1&AIN2...................................................................... 52

FIGURE 28: REFERENCE DESIGN FOR AOUT1 .............................................................................. 52

FIGURE 29: HANDSET INTERFACE DESIGN FOR AOUT2 ........................................................... 53

FIGURE 30: SPEAKER INTERFACE DESIGN WITH AN AMPLIF IER F OR AOUT2 ..................... 53

FIGURE 31: EARPHONE INTERFACE DESIGN ............................................................................... 54

FIGURE 32: LOUD SPEAKER INTERFACE DESIGN ....................................................................... 54

FIGURE 33: REFERENCE CIRCUIT OF THE 8 PINS SIM CARD .................................................... 56

FIGURE 34: REFERENCE CIRCUIT OF THE 6 PINS SIM CARD .................................................... 57

FIGURE 35: AMPHENOL C707 10M006 512 2 SIM CARD HOLDER .............................................. 58

FIGURE 36: MOLEX 91228 S IM CARD HOLDER ............................................................................ 59

FIGURE 37: REFERENCE CIRCUIT OF SD CARD ........................................................................... 60

FIGURE 38: LONG SYNCHRONIZATION & SIGN EXTENSION DIAGRAM ............................... 63

FIGURE 39: LONG SYNCHRONIZATION & ZERO PADDING DIAGRAM ................................... 63

FIGURE 40: SHORT SYNCHRONIZATION & SIGN EXTENSION DIAGRAM .............................. 63

FIGURE 41: SHORT SYNCHRONIZATION & ZERO PADDING DIAGRAM ................................. 64

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FIGURE 42: REFERENCE DESIGN FOR PCM .................................................................................. 64

FIGURE 43: RI BEHAVIOR OF VOICE CALLING AS A RECEIVER .............................................. 67

FIGURE 44: RI BEHAVIOR OF DATA CALLING AS A RECEIVER ................................................ 67

FIGURE 45: RI BEHAVIOR AS A CALLER ........................................................................................ 67

FIGURE 46: RI BEHAVIOR OF URC OR SMS RECEIVED .............................................................. 68

FIGURE 47: REFERENCE DESIGN FOR NETLIGHT ....................................................................... 69

FIGURE 48: REFERENCE DESIGN FOR STATUS ............................................................................ 70

FIGURE 49: REFERENCE DESIGN FOR RF ...................................................................................... 71

FIGURE 50: RF SOLDERING SAMP LE.............................................................................................. 73

FIGURE 51: M50 TOP AND SIDE DIMENSIONS .............................................................................. 79

FIGURE 52: M50 BOTTOM DIMENSIONS ........................................................................................ 80

FIGURE 53: RECOMMENDED FOOTPRINT WITHOUT BOTTOM CENTRE PADS .................... 81

FIGURE 55: TOP VIEW OF THE MODULE ....................................................................................... 82

FIGURE 56: BOTTOM VIEW OF THE MODULE .............................................................................. 83

FIGURE 57: PASTE APPLICATION .................................................................................................... 85

FIGURE 58: RAMP-SOAK-SPIKE REFLOW PROFILE .................................................................... 86

FIGURE 59: MODULE TRAY .............................................................................................................. 86

FIGURE 60: RADIO BLOCK STRUCTURE OF CS-1, CS-2 AND CS-3 ........................................... 87

FIGURE 61: RADIO BLOCK STRUCTURE OF CS-4 ........................................................................ 87

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0. Revision history

Revision Date Author Description of change

1.0 2011-12-20 Ray XU Initial

1.1 2012-02-03 Ray XU 1. Updated PCM interface

2. Updated SD interface

3. Updated charging interface

4. Updated timing of turning on the module

1.2 2012-07-20 Baly BAO 1. Deleted the USB interface

2. Deleted the camera interface

1.3 2012-10-22 Mountain ZHOU 1. Updated functional diagram

2. Updated reference design circuit

3. Updated audio characteristics

4. Updated VRTC DC characteristics

5. Updated SLEEP current consumption

6. Updated internet service protocols

7. Updated SIM pins’ name

8. Modified PCM function

9. Deleted FAX function

2.0 2012-06-16 Ray XU 1. Update the module size

2. Update the pin layout

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1. Introduction

This document defines the M50 module and describes the hardware interface of M50 which are

connected with the customer application and the air interface.

This document can help customers quickly understand module interface specifications, electrical

and mechanical details. Associated with application notes and user guide, customers can use

M50module to design and set up mobile applications e a sil y.

1.1. Related documents

Table 1: Related documents

SN Document name Remark

[1] M50_ AT C AT commands set

[2] ITU-T

Draft new

recommendation V.25ter

Serial asynchronous automatic dialing and control

[3] GSM 07.07

Digital cellular telecommunications (Phase 2+); AT

command set for GSM Mobile Equipment (ME)

[4] GSM 07.10 Support GSM 07.10 multiplexing protocol

[5] GSM 07.05 Digital cellular telecommunications (Phase 2+); Use

of Data Terminal Equipment –

Data Circuit

terminating Equipment (DTE –

DCE) interface for

Short Message Service (SMS) and Cell Broadcast

Service (CBS)

[6] GSM 11.14 Digital cellular telecommunications (P

hase 2+);

Specification of the SIM Application Toolkit for the

Subscriber Identity module – Mobile Equipment (SIM

– ME) interface

[7] GSM 11.11

Digital cellular telecommunications (Phase 2+);

Specification of the Subscriber Identity module –

Mobile Equipment (SIM – ME) interface

[8] GSM 03.38

Digital cellular telecommunications (Phase 2+);

Alphabets and language-specific information

[9] GSM 11.10 Digital cellular telecommunications (Phase 2); Mobile

Station (MS) conformance specification; Part 1:

Conformance specification

[10] GSM_UART_AN UART port application note

[11] GSM_FW_Upgrade_AN01 GSM Firmware upgrade application note

[12] M10_EVB_UGD M10 EVB user guide

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1.2. Terms and abbreviations

Table 2: Terms and abbreviations

Abbreviation Description

ADC Analog-to-Digital Converter

AMR Adaptive Multi-Rate

ARP Antenna Reference Point

ASIC Application Specific Integrated Circuit

BER Bit Error Rate

BOM Bill Of Material

BTS Base Transceiver Station

CHAP Challenge Handshake Authentication Protocol

CS Coding Scheme

CSD Circuit Switched Data

CTS Clear To Send

DAC Digital-to-Analog Converter

DRX Discontinuous Reception

DSP Digital Signal Processor

DCE Data Communications Equipment (typically module)

DTE Data Terminal Equipment (typically computer, external controller)

DTR Data Terminal Ready

DTX Discontinuous Transmission

EFR Enhanced Full Rate

EGSM Enhanced GSM

EMC Electromagnetic Compatibility

ESD Electrostatic Discharge

ETS European Telecommunication Standard

FCC Federal Communications Commission (U.S.)

FDMA Frequency Division Multiple Access

FR Full Rate

GMSK Gaussian Minimum Shift Keying

GPRS General Packet Radio Service

GSM Global System for Mobile Communications

HR Half Rate

I/O Input/Output

IC Integrated Circuit

IMEI International Mobile Equipment Identity

Imax Maximum Load Current

Inorm Normal Current

kbps Kilo Bits Per Second

LED Light Emitting Diode

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Li-Ion Lithium-Ion

MO Mobile Originated

MS Mobile Station (GSM engine)

MT Mobile Terminated

PAP Password Authentication Protocol

PBCCH Packet Switched Broadcast Control Channel

PCB Printed Circuit Board

PDU Protocol Data Unit

PPP Point-to-Point Protocol

RF Radio Frequency

RMS Root Mean Square (value)

RTC Real Time Clock

RX Receive Direction

SIM Subscriber Identification Module

SMS Short Message Service

TDMA Time Division Multiple Access

TE Terminal Equipment

TX Transmitting Direction

UART Universal Asynchronous Receiver & Transmitter

URC Unsolicited Result Code

USSD Unstructured Supplementary Service Data

VSWR Voltage Standing Wave Ratio

Vmax Maximum Voltage Value

Vnorm Normal Voltage Value

Vmin Minimum Voltage Value

VIHmax Maximum Input High Level Voltage Value

VIHmin Minimum Input High Level Voltage Value

VILmax Maximum Input Low Level Voltage Value

VILmin Minimum Input Low Level Voltage Value

VImax Absolute Maximum Input Voltage Value

VImin Absolute Minimum Input Voltage Value

VOHmax Maximum Output High Level Voltage Value

VOHmin Minimum Output High Level Voltage Value

VOLmax Maximum Output Low Level Voltage Value

VOLmin Minimum Output Low Level Voltage Value

Phonebook abbreviations

LD SIM Last Dialing phonebook (list of numbers most recently dialed)

MC Mobile Equipment list of unanswered MT Calls (missed calls)

ON SIM (or ME) Own Numbers (MSISDNs) list

RC Mobile Equipment list of Received Calls

SM SIM phonebook

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1.3. Safety cautions

The following safety precautions must be observed during all phases of the operation, such as

usage, service or repair of any cellular terminal or mobile incorporating M50module.

Manufacturers of the cellular terminal should send the following safety information to users and

operating personnel and to incorporate these guidelines into all manuals supplied with the product.

If not so, Quectel does not take on any liability for customer failure to comply with these

precautions.

When in a hospital or other health care facility, observe the restrictions about the

use of mobile. Switch the cellular terminal or mobile off. Medical equipment may

be sensitive to not operate normally for RF energy interference.

Switch off the cellular terminal or mobile before boarding an aircraft. Make sure

it switched off. The operation of wireless appliances in an aircraft is forbidden to

prevent interference with communication systems. Forget to think much of these

instructions may lead to the flight safety or offend against local legal action, or

both.

Do not operate the cellular terminal or mobile in the presence of flammable gas

or fume. Switch off the cellular terminal when you are near petrol

station, fuel

depot, chemical plant or where blasting operations are in progress. Operation of

any electrical equipment in potentially explosive atmosphere can constitute a

safety hazard.

Your cellular terminal or mobile receives and transmits radio frequency energy

while switched on. RF interference can occur if it is used close to TV set, radio,

computer or other electric equipment.

Road safety comes first! Do not use a hand-held cellular terminal or mobile while

driving a vehicle, unless it is securely mounted in a holder for hands-free

operation. Before making a call with a hand-held terminal or mobile, park the

vehicle.

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According to the R&TTE Directive 1999/95/CE, all wireless equipment and

telecommunications terminals sold in EU must meet all the stipulated health,

safety RF, EMC requirements that provide for CE mark. Quectel Module M50

is fully in accordance with all the directives of EU.

1.4. Directives and standards

The M50 module is designed to comply with the FCC statements. FCC ID: XMR201211M50.

The Host system using M50, should have label indicated contains FCC ID: XMR201211M50.

1.4.1. FCC Statement

1. This device complies with Part 15 of the FCC rules. Operation is subject to the following

conditions:

a) This device may not cause harmful interference.

b) This device must accept any interference received, including interference that may cause

undesired operation.

2. Changes or modifications not expressly approved by the party responsible for compliance

could void the user’s authority to operate the equipment.

1.4.2. FCC Radiation exposure statement

This equipment complies with FCC radiation exposure limits set forth for an uncontrolled

environment. This equipment should be installed and operated with minimum distance 20cm

between the radiator and your body as well as kept minimum 20cm from radio antenna depending

on the Mobile status of this module usage.

GSM cellular terminals or mobiles operate over radio frequency signal and

cellular network and cannot be guaranteed to connect in all conditions, for

example no mobile fee or an invalid SIM card. While you are in this condition

and need emergent help, Please Remember using emergency call. In order to

make or receive call, the cellular terminal or mobile must be switched on and in

a service area with adequate cellular signal strength.

Some networks do not allow for emergency call if certain network services or

phone features are in use (e.g. lock functions, fixed dialing etc.). You may have

to deactivate those features before you can make an emergency call.

Also, some networks require that a valid SIM card be properly inserted in

cellular terminal or mobile.

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The manual of the host system, which uses M50, must include RF exposure warning statement to

advice user should keep minimum 20cm from the radio antenna of M50 module depending on the

Mobile status.

The following list of antenna is indicating the maximum permissible antenna gain.

Type Maximum Gain

(850Hz/900Hz)

Maximum Gain

(1800Hz/1900Hz)

Impedance

External

Antenna

Monopole 0.5dBi 2dBi 50Ω

Vehicular antenna 0.5dBi 2dBi 50Ω

Internal

Antenna

Monopole 0.5dBi 2dBi 50Ω

PIFA 0.5dBi 2dBi 50Ω

FPC 0.5dBi 2dBi 50Ω

PCB 0.5dBi 2dBi 50Ω

This radio module must not be installed to co-locate and operate simu

ltaneously with other radios in host system;

additional testing and equipment authorization may be required to op

erating simultaneously with other radios.

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2. Product concept

M50 is a Quad-band GSM/GPRS engine that works at frequencies of GSM850MHz,

GSM900MHz, DCS1800MHz and PCS1900MHz. The M50 features GPRS multi-slot class 12

and supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. For more details about

GPRS multi-slot classes and coding schemes, please refer to the Appendix A and Appendix B.

With a tiny profile of 24.5mm×25.3mm ×2.6mm, the module can meet almost all the requirements

for M2M applications, including Vehicles and Personal Tracking, Security System, Wireless POS,

Industrial PDA, Smart Metering, and Remote Maintenance & Control etc.

M50 is an SMD type module with LCC package, which can be embedded in customer’s

applications. It provides abundant hardware interfaces between the module and customer’s host

board.

Designed with power saving technique, the current consumption of M50 is as low as 1.3 mA in

SLEEP mode when DRX is 5.

M50 is integrated with Internet service protocols, such as TCP, UDP, FTP and PPP. Extended AT

commands have been developed for customer to use these Internet service protocols easily.

The module fully complies with the RoHS directive of the European Union.

2.1. Key features

Table 3: Module key features

Feature Description

Power supply Single supply voltage 3.3V~ 4.6V

Typical supply voltage 4.0V

Power saving Typical power consumption in SLEEP mode: 1.3 mA@ DRX=5

1.2 mA@ DRX=9

Frequency bands  Quad-band: GSM850, GSM900, DCS1800, PCS1900.

 The module can search these frequency bands automatically

 The frequency bands can be set by AT command.

 Compliant with GSM Phase 2/2+

GSM class Small MS

Transmitting power  Class 4 (2W) at GSM850 and GSM900

 Class 1 (1W) at DCS1800 and PCS1900

GPRS connectivity  GPRS multi-slot class 12 (default)

 GPRS multi-slot class 1~12 (configurable)

 GPRS mobile station class B

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Temperature range  Normal operation: -35°C ~ +80°C

 Restricted operation: -40°C ~ -35°C and +80°C ~ +85°C 1)

 Storage temperature: -45°C ~ +90°C

DATA GPRS:

CSD:

 GPRS data downlink transfer: max. 85.6 kbps

 GPRS data uplink transfer: max. 85.6 kbps

 Coding scheme: CS-1, CS-2, CS-3 and CS-4

 Support the protocols PAP (Password Authentication Protocol)

usually used for PPP connections

 Internet service protocols

TCP/UDP/FTP/PPP/HTTP/NTP/PING

 Support Packet Broadcast Control Channel (PBCCH)

 CSD transmission rates: 2.4, 4.8, 9.6, 14.4 kbps non-transparent

 Support Unstructured Supplementary Service Data (USSD)

SMS  Text and PDU mode

 SMS storage: SIM card

SIM interface Support SIM card: 1.8V, 3V

Audio features Speech codec modes:

 Half Rate (ETS 06.20)

 Full Rate (ETS 06.10)

 Enhanced Full Rate (ETS 06.50 / 06.60 / 06.80)

 Adaptive Multi-Rate (AMR)

 Echo Suppression

 Echo Cancellation

 Noise Reduction

 Embedded one amplifier of class AB with maximum driving

power up to 800mW

UART interfaces UART Port:

 Seven lines on UART port interface

 Used for AT command, GPRS data and CSD data

 Multiplexing function

 Support autobauding from 4800 bps to 115200 bps

Debug Port:

 Two lines on debug port interface DBG_TXD and DBG_RXD

 Debug Port only used for firmware debugging

Auxiliary Port:

 Used for AT command

Phonebook management Support phonebook types: SM, ME, ON, MC, RC, DC, LD, LA

SIM Application Toolkit Support SAT class 3, GSM 11.14 Release 99

Real time clock Supported

Physical characteristics Size:

24.5 (±0.15) × 25.3 (±0.15) × 2.6 (±0.2) mm

Weight: 3.3g

Firmware upgrade Firmware upgrade via UART Port

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Antenna interface Connected to antenna pad with 50 Ohm impedance control

1

）

When the module works in this temperature range, the deviations from the GSM specification

may occur. For example, the frequency error or the phase error will be increased.

Table 4: Coding schemes and maximum net data rates over air interface

Coding scheme 1 Timeslot 2 Timeslot 4 Timeslot

CS-1 9.05kbps 18.1kbps 36.2kbps

CS-2 13.4kbps 26.8kbps 53.6kbps

CS-3 15.6kbps 31.2kbps 62.4kbps

CS-4 21.4kbps 42.8kbps 85.6kbps

2.2. Functional diagram

The following figure shows a block diagram of the M50 module and illustrates the major

functional parts:

 Power management

 Baseband

 Serial Flash

 The radio frequency part

 The peripheral interface

—Charge interface

—PCM interface

—SD interface

—SIM interface

—Audio interface

—Serial interface

—Power supply

—RF interface

—ADC

—Turn on/off interface (PWRKEY & EMERG_OFF)

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BB&RF

RF PAM

SAW

Filter

Serial

Flash

32KHz

26MHzRF Transceiver

Audio

RTC

GPIO

Serial

Interface Memory

Interface

PCM

Interface

SIM

Interface

SD

Interface

ADC

RF_ANT

VBAT

PWRKEY

EMERG_OFF

VRTC

ADC

STATUS&

NETLIGHT

UART

SIM

Interface

Audio

SD

Interface

PCM

Inteface

Reset

ESD

PMU

Charge

Interface Charge

Figure 1: Module functional diagram

2.3. Evaluation board

In order to help customer to develop applications with M50 , Quectel supplies an evaluation board

(EVB), RS-232 to USB cable, power adapter, earphone, antenna and other peripherals to control

or test the module. For details, please refer to the document [12].

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3. Application interface

The module is equipped with 83-pin SMT pads and it adopts LCC package. Detailed descriptions

on Sub-interfaces included in these pads are given in the following chapters:

 Power supply

 Power on/down

 Charge interface

 RTC

 Serial interfaces

 Audio interfaces

 SIM interface

 SD interface

 PCM interface

 ADC

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3.1. Pin of module

3.1.1. Pin assignment

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

575859606162636465666768697071727374

Top view

75

76

77

78

79

80

81

82

83

SIM_PRESENCE

RESERVED

VRTC

VDD_EXT

GND

RF_ANT

GND

VBAT

RESERVED

ADC1

ADC0

RESERVED

NETLIGHT

SPK2P

AGND

MIC2P

MIC2N

MIC1P

MIC1N

SPK1N

SPK1P

LOUDSPKN

LOUDSPKP

STATUS

PWRKEY

EMERG_OFF

PCM_IN

PCM_CLK RESERVED

RESERVED

TXD_AUX

RXD_AUX

DBG_TXD

DBG_RXD

RESERVED

DCD

RI

DTR

CTS

RTS

RXD

TXD

SIM1_GND

SIM1_RST

SIM1_CLK

SIM1_DATA

SIM1_VDD

VBAT GND PCM

RF UART

Power SIM Reserved Audio

ADC

Other

SD

PCM_OUT

PCM_SYNC

RESERVED

SD_CMD

SD_CLK

SD_DATA0

GND

RESERVED

GND

Figure 2: Pin assignment

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Table 5: M50 pin assignment

管脚号

管脚名

输入

/

输出

管脚号

管脚名

输入

/

输出

1 ADC1 I 2 ADC0 I

3 RESERVED 4 NETLIGHT O

5 SPK2P O 6 AGND

7 MIC2P I 8 MIC2N I

9 MIC1P I 10 MIC1N I

11 SPK1N O 12 SPK1P O

13 LOUDSPKN O 14 LOUDSPKP O

15 S TAT U S O 16 PWRKEY I

17 EMERG_OFF I 18 PCM_IN I

19 PCM_CLK O 20 PCM_OUT O

21 PCM_SYNC O 22 RESERVED

23 RESERVED 24 RESERVED

25 RESERVED 26 RESERVED

27 RESERVED 28 RESERVED

29 RESERVED 30 RESERVED

31 RESERVED 32 RESERVED

33 RESERVED 34 SD_CMD O

35 SD_CLK O 36 SD_DATA0 I/O

37 GND 38 RESERVED

39 RESERVED 40 TXD_AUX O

41 RXD_AUX I 42 DBG_TXD O

43 DBG_RXD I 44 RESERVED

45 DCD O 46 RI O

47 DTR I 48 CTS O

49 RTS I 50 RXD I

51 TXD O 52 SIM_GND

53 SIM_RST O 54 SIM_CLK O

55 S I M _ D ATA I/O 56 SIM_VDD O

57 SIM_PRESENCE I 58 RESERVED

59 VRTC I/O 60 VDD_EXT O

61 GND 62 GND

63 RF_ANT I/O 64 GND

65 GND 66 GND

67 V B AT I 68 V B AT I

69 V B AT I 70 V B AT I

71 RESERVED 72 RESERVED

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73 RESERVED 74 RESERVED

75 RESERVED 76 RESERVED

77 RESERVED 78 RESERVED

79 GND 80 GND

81 GND 82 GND

83 GND

Note: Keep all reserved pins open.

3.1.2. Pin description

Table 6: Pin description

Power supply

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

V B AT 67,

68,

69，

70

I Main power supply

of module:

VBAT=3.3V~4.6V

Vmax= 4.6V

Vmin=3.3V

Vnorm=4.0V

Make sure that

supply sufficient

current in a

transmitting

burst which

typically rises to

1.6A.

VRTC 59 I/O Power supply for

RTC when V B AT is

not supplied for the

system.

Charging for backup

battery or golden

capacitor when the

VBAT is supplied.

VImax=3.3V

VImin=1.5V

VInorm=2.8V

VOmax=2.85V

VOmin=2.6V

VOnorm=2.8V

Iout(max)= 1mA

Iin=2.6~5 uA

If unused, keep

this pin open.

VDD_EXT 60 O Supply 2.8V voltage

for external circuit.

Vmax=2.9V

Vmin=2.7V

Vnorm=2.8V

Imax=20mA

1. If unused,

keep this pin

open.

2. Recommended

to add a

2.2~4.7uF

bypass capacitor

when supplying

power for

external circuit.

GND 37,

61,

Ground

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62,

64,

65,

66,

Turn on/off

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

PWRKEY 15 I Turn on/off control.

PWRKEY should be

pulled down for a

moment to turn on

or off the system.

VILmax=

0.1×V B AT

VIHmin=

0.6×V B AT

V I m a x = V B AT

Pulled up to

VBAT internally.

Emergency shutdown

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

EMERG_OFF 17 I Emergency off.

Pulled down for at

least 20ms, which

will turn off the

module in case of

emergency. Use it

only when normal

shutdown through

PWRKEY or AT

command cannot

perform well.

VILmax=0.4V

VIHmin=2.2V

Vopenmax=2.8V

Open

drain/collector

driver required in

cellular device

application.

If unused, keep

this pin open.

Module indicator

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

S TAT U S 16 O Indicate module

operating status.

High level indicates

module is power-on

and low level

indicates

power-down.

VOHmin=

0.85×VDD_EXT

VOLmax=

0.15×VDD_EXT

If unused, keep

this pin open.

Audio interface

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

MIC1P

MIC1N

9, 10 I Channel one for

positive and

negative voice-band

input

If unused, keep

these pins open.

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MIC2P

MIC2N

7, 8 I Channel two for

positive and

negative voice-band

input

SPK1P

SPK1N

12, 11

O Channel one for

positive and

negative voice-band

output

1. If unused,

keep these pins

open.

2. Support both

voice and

ringtone output.

SPK2P 5 O Channel two for

voice-band output

AGND 6 Analog ground.

Constitute a pseudo

differential channel

with SPK2P.

LOUDSPKN

LOUDSPKP

13,

14

O Channel three of

positive and

negative voice-band

output

1. If unused,

keep these pins

open.

2. Embedded

amplifier of class

AB internally.

3. Support both

voice and

ringtone output.

Net status indicator

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

NETLIGHT 4 O Network status

indication

VOHmin=

0.85×VDD_EXT

VOLmax=

0.15×VDD_EXT

If unused, keep

this pin open.

UART Port

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

DTR 47 I Data terminal ready VILmin=0V

VILmax=

0.25×VDD_EXT

VIHmin=

0.75×VDD_EXT

VIHmax=

VDD_EXT+0.3

VOHmin=

0.85×VDD_EXT

VOLmax=

If only use TXD,

RXD and GND

to communicate,

recommend

pulling down

RTS and keeping

other pins open.

RXD 50 I Receive data

TXD 49 O Transmit data

RTS 51 I Request to send

CTS 48 O Clear to send

RI 46 O Ring indicator

DCD 45 O Data carrier

detection

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0.15×VDD_EXT

Debug Port

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

DBG_TXD 42 O UART interface for

debugging only.

VILmin=0V

VILmax=

0.25×VDD_EXT

VIHmin=

0.75×VDD_EXT

VIHmax=

VDD_EXT+0.3

VOHmin=

0.85×VDD_EXT

VOLmax=

0.15×VDD_EXT

If unused, keep

these pins open.

DBG_RXD 43 I

Auxiliary UART Port

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

TXD_AUX 40 O Transmit data VILmin=0V

VILmax=

0.25×VDD_EXT

VIHmin=

0.75×VDD_EXT

VIHmax=

VDD_EXT+0.3

VOHmin=

0.85×VDD_EXT

VOLmax=

0.15×VDD_EXT

If unused, keep

these pins open.

RXD_AUX 41 I Receive data

SIM interface

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

SIM_VDD 56 O Power supply for

SIM card

The voltage can be

selected by firmware

automatically. Either

1.8V or 3V.

All signals of

SIM interface

should be

protected against

ESD with a TVS

diode array.

Maximum cable

length is 200mm

from the module

pad to SIM card

S I M _ D ATA 54 I/O SIM data 3V：

VOLmax=0.4

VOHmin=

SIM_VDD-0.4

1.8V:

VOLmax=

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0.15×SIM_VDD

VOHmin=

SIM_VDD-0.4

holder.

SIM_CLK 55 O SIM clock 3V：

VOLmax=0.4

VOHmin=

0.9×SIM_VDD

1.8V:

VOLmax=

0.12×SIM_VDD

VOHmin=

0.9×SIM_VDD

SIM_RST 53 O SIM reset 3V：

VOLmax=0.36

VOHmin=

0.9×SIM_VDD

1.8V:

VOLmax=

0.2×SIM_VDD

VOHmin=

0.9×SIM_VDD

SIM_GND 52 SIM ground

SIM_PRESEN

CE

57 I SIM card detection VILmin=0V

VILmax=

0.25×VDD_EXT

VIHmin=

0.75×VDD_EXT

VIHmax=

VDD_EXT+0.3

If unused, keep

this pin open.

ADC

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

ADC0 2 I General purpose

analog to digital

converter.

Voltage range: 0V to

2.8V

Please give

priority to the

use of ADC0.

If unused, keep

these pins open.

ADC1 1 I General purpose

analog to digital

converter.

Voltage range: 0V to

2.8V

PCM

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

PCM_CLK 19 O PCM clock VILmin=0V

VILmax=

PCM_IN 18 I PCM data input

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PCM_OUT 20 O PCM data output 0.25×VDD_EXT

VIHmin=

0.75×VDD_EXT

VIHmax=

VDD_EXT+0.3

VOHmin=

0.85×VDD_EXT

VOLmax=

0.15×VDD_EXT

PCM_SYNC 21 O PCM frame

synchronization

SD card

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

SD_CMD 34 O SD command VILmin=0V

VILmax=

0.25×VDD_EXT

VIHmin=

0.75×VDD_EXT

VIHmax=

VDD_EXT+0.3

VOHmin=

0.85×VDD_EXT

VOLmax=

0.15×VDD_EXT

SD_CLK 35 O SD clock

SD_DATA0 36 I/O SD data

RF interface

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

RF_ANT 63 I/O RF antenna pad Impedance of 50Ω

Other interface

PIN NAME PIN

NO.

I/O DESCRIPTION DC

CHARACTERISTICS

COMMENT

DOWNLOAD 3 I VILmin=0V

VILmax=

0.25×VDD_EXT

VIHmin=

0.75×VDD_EXT

VIHmax=

VDD_EXT+0.3

Keep this pin

open.

RESERVED 22~

33，

38~

39,

44,

58,

Keep these pins

open.

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71~

75

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3.2. Operating modes

The table below briefly summarizes the various operating modes in the following chapters.

Table 7: Overview of operating modes

Mode Function

Normal operation GSM/GPRS

SLEEP

The module will automatically go into SLEEP mode if DTR

is set to high level and there is no interrupt (such as GPIO

interrupt or data on UART port).

In this case, the current consumption of module will reduce

to the minimal level.

During SLEEP mode, the module can still receive paging

message and SMS from the system normally.

GSM IDLE Firmware is active. The module has registered to the GSM

network, and the module is ready to send and receive GSM

data.

GSM TALK

GSM connection is ongoing. In this mode

, the power

consumption is decided by the configuration of Power

Control Level (PCL), dynamic DTX control and the working

RF band.

GPRS IDLE The module is not registered to GPRS network. The module

is not reachable through GPRS channel.

GPRS

STANDBY

The module is registered to GPRS network, but

no GPRS

PDP context is active. The SGSN knows the Routing Area

where the module is located at.

GPRS

READY

The PDP context is active, but no data transfer is ongoing.

The module is ready to receive or send GPRS data. The

SGSN knows the cell where the module is located at.

GPRS DATA There is GPRS data in transfer. In this mode

, power

consumption is

decided by the PCL, working RF band and

GPRS multi-slot configuration.

Power down Normal shutdown by sending the “AT+QPOWD=1” command, using the

PWRKEY or the EMERG_OFF1) pin. The power management ASIC

disconnects the power supply from the base band part of the module, and only

the power supply for the RTC is remained. Software is not active. The UART

interfaces are not accessible. Operating voltage (connected to VBAT) remains

applied.

Minimum

functionality

mode (without

removing power

supply)

“AT+CFUN” command can set the module to a minimum functionality mode

without removing the power supply. In this case, the RF part of the module

will not work or the SIM card will not be accessible, or both RF part and SIM

card will be disabled, but the UART port is still accessible. The power

consumption in this case is very low.

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1) Use the EMERG_OFF pin only while failing to turn off the module by the command

“AT+QPOWD=1” and the PWRKEY pin. Please refer to the Section 3.4.2.4.

3.3. Power supply

3.3.1. Power features of module

The power supply is one of the key issues in the designing GSM terminals. Due to the 577us radio

burst emission in GSM every 4.615ms, power supply must be able to deliver high current peaks in

a burst period. During these peaks, drops on the supply voltage must not exceed minimum

working voltage of module.

For the M50 module, the max current consumption could reach to 1.6A during a transmit burst. It

will cause a large voltage drops on the VBAT. In order to ensure stable operation of the module, it

is recommended that the max voltage drop during the transmit burst does not exceed 400mV.

Vdrop

4.615ms

577us

I

VBAT

Burst:1.6A

Figure 3: Voltage ripple during transmitting

3.3.2. Decrease supply voltage drop

The power supply rang of the module is 3.3V to 4.6V. Make sure that the input voltage will never

drop below 3.3V even in a transmitting burst. If the power voltage drops below 3.3V, the module

could turn off automatically. For better power performance, it is recommended to place a 100uF

tantalum capacitor with low ESR (ESR=0.7Ω) and ceramic capacitor 100nF, 33pF and 10pF near

the VBAT pin. The reference circuit is illustrated in Figure 4.

The V B AT r o u t e should be wide enough to ensure that there is not too much voltage drop

occurring during transmit burst. The width of trace should be no less than 2mm and the principle

of the VBAT route is the longer route, the wider trace.

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VBAT

C2C1

+C3 C4

GND

100uF 100nF 10pF

0603

33pF

0603

Figure 4: Reference circuit for the VBAT input

3.3.3. Reference design for power supply

The power design for the module is very important, since the performance of power supply for the

module largely depends on the power source. The power supply is capable of providing the

sufficient current up to 2A at least. If the voltage drop between the input and output is not too high,

it is suggested to use a LDO as module’s power supply. If there is a big voltage difference

between the input source and the desired output (VBAT), a switcher power converter is prefer to

use as a power supply.

Figure 5 shows a reference design for +5V input power source. The designed output for the power

supply is 4.16V and the maximum load current is 3A. In addition, in order to get a stable output

voltage, a zener diode is placed close to the pins of VBAT. As to the zener diode, it is suggested to

use a zener diode which reverse zener voltage is 5.1V and dissipation power is more than 1 Watt.

DC_IN

C1 C2

MIC29302 U1

IN OUT

EN

GND

ADJ

2 4

1

3

5

VBAT

100nF

C3

470uF

C4

100nF

R1

D1

120K

51K

R2

470uF

Figure 5: Reference circuit for power supply

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3.3.4. Monitor power supply

To monitor the supply voltage, customer can use the “AT+CBC” command which includes three

parameters: charging status, remaining battery capacity and voltage value (in mV). It returns the

0~100 percent of battery capacity and actual value measured between VBAT and GND. The

voltage is automatically measured in period of 5s. The displayed voltage (in mV) is averaged over

the last measuring period before the “AT+CBC” command is executed.

For details, please refer to the document [1].

3.4. Power on and down scenarios

3.4.1. Power on

Customer’s application can turn on the module by driving the pin PWRKEY to a low level voltage,

and after STATUS pin outputs a high level, PWRKEY pin can be released. Customer may monitor

the level of the STATUS pin to judge whether the module is power-on or not. An open collector

driver circuit is suggested to control the PWRKEY. A simple reference circuit is illustrated as

below.

Turn on pulse

PWRKEY

4.7K

47K

Figure 6: Turn on the module using driving circuit

Note: The module is set to autobauding mode (AT+IPR=0) in default configuration. In the

autobauding mode, the URC “RDY” after powering on is not sent to host controller. When the

module receives AT command, it will be powered on after a delay of 2 or 3 seconds. Host

controller should firstly send an “AT” or “at” string in order that the module can detect baud

rate of host controller, and it should send the second or the third “ AT” or “at” string until

receiving “OK” string from the module. Then an “AT+IPR=x;&W” should be sent to set a fixed

baud rate for the module and save the configuration to flash memory of the module. After these

configurations, the URC “RDY” would be received from the UART Port of the module every

time when the module is powered on. Refer to the section “AT+IPR” in document [1].

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The other way to control the PWRKEY is using a button directly. A TVS component is

indispensable to be placed nearby the button for ESD protection. When pressing the key,

electrostatic strike may generate from finger. A reference circuit is shown in the following figure.

S1

PWRKEY

TVS1

Close to S1

Figure 7: Turn on the module using keystroke

The power-on scenarios is illustrated as the following figure.

EMERG_OFF

(INPUT)

VDD_EXT

(OUTPUT)

VIL<0.1*VBAT

VIH > 0.6*VBAT

VBAT

PWRKEY

(INPUT)

54ms

STATUS

(OUTPUT)

800ms

>1s

OFF BOOTING

MODULE

STATUS

RUNNING

2

1

Figure 8: Timing of turning on system

① Make sure that VBAT is stable before pulling down PWRKEY pin. The time between them

is recommended 30ms.

② EMERG_OFF should be floated when it is unused

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3.4.2. Power down

The following procedures can be used to turn off the module:

 Normal power down procedure: Turn off module using the PWRKEY pin

 Normal power down procedure: Turn off module using command “AT+QPOWD”

 Over-voltage or under-voltage automatic shutdown: Take effect when over-voltage o r

under-voltage is detected

 Emergent power down procedure: Turn off module using the EMERG_OFF pin

3.4.2.1. Power down module using the PWRKEY pin

Customer’s application can turn off the module by driving the PWRKEY to a low level voltage for

a certain time. The power down scenario is illustrated in Figure 9.

VBAT

PWRKEY

(INPUT)

STATUS

(OUTPUT)

EMERG_OFF

(INPUT)

Logout net about 2s to 12s

0.6s<Pulldown<1s

>160us

Figure 9: Timing of turning off the module

The power down procedure causes the module to log off from the network and allows the

firmware to save important data before completely disconnecting the power supply, thus it is a

safe way.

Before the completion of the power down procedure, the module sends out the result code shown

below:

NORMAL POWER DOWN

Note: This result code does not appear when autobauding is active and DTE and DCE are not

correctly synchronized after start-up. The module is recommended to set a fixed baud rate.

After that moment, no further AT commands can be executed. Then the module enters the power

down mode, only the RTC is still active. The power down mode can also be indicated by the

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STATUS pin, which is a low level voltage in this mode.

3.4.2.2. Power down module using AT command

Customer’s application can turn off the module via AT command “AT+QPOWD=1”. This

command will let the module to log off from the network and allow the firmware to save

important data before completely disconnecting the power supply, thus it is a safe way.

Before the completion of the power down procedure the module sends out the result code shown

below:

NORMAL POWER DOWN

After that moment, no further AT commands can be executed. And then the module enters the

power down mode, only the RTC is still active. The power down mode can also be indicated by

STATUS pin, which is a low level voltage in this mode.

Please refer to the document [1] for details about the AT command “AT+QPOWD”.

3.4.2.3. Over-voltage or under-voltage automatic shutdown

The module will constantly monitor the voltage applied on the VBAT, if the voltage is ≤ 3.5V,

the following URC will be presented:

UNDER_VOLTAGE WARNING

If the voltage is ≥ 4.5V, the following URC will be presented:

OVER_VOLTAGE WARNING

The normal input voltage range is from 3.3V to 4.6V. If the voltage is > 4.6V or < 3.3V, the

module would automatically shutdown itself.

If the voltage is < 3.3V, the following URC will be presented:

UNDER_VOLTAGE POWER DOWN

If the voltage is > 4.6V, the following URC will be presented:

OVER_VOLTAGE POWER DOWN

Note: These result codes do not appear when autobauding is active and DTE and DCE are not

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correctly synchronized after start-up. The module is recommended to set to a fixed baud rate.

After that moment, no further AT commands can be executed. The module logs off from network

and enters power down mode, and only RTC is still active. The power down mode can also be

indicated by the pin STATUS, which is a low level voltage in this mode.

3.4.2.4. Emergency shutdown using EMERG_OFF pin

The module can be shut down by driving the pin EMERG_OFF to a low level voltage over 20ms

and then releasing it. The EMERG_OFF line can be driven by an open-drain/collector driver or a

button. The circuit is illustrated as the following figures.

Emergency

shutdown pulse

EMERG_OFF

4.7K

47K

Figure 10: Reference circuit for EMERG_OFF by using driving circuit

S2

EMERG_OFF

TVS2

Close to S2

Figure 11: Reference circuit for EMERG_OFF by using button

3.4.3. Restart

Customer’s application can restart the module by driving the PWRKEY to a low level voltage for

a certain time, which is similar to the way of turning on module. Before restarting the module, at

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least 500ms should be delayed after detecting the low level of STATUS. The restart timing is

illustrated as the following figure.

PWRKEY

(INPUT)

STATUS

(OUTPUT)

Delay >0.5s

Turn off Restart

Pull down the PWRKEY

to turn on the module

Figure 12: Timing of restarting system

The module can also be restarted by the PWRKEY after emergency shutdown.

EMERG_OFF

(INPUT)

STATUS

(OUTPUT)

Delay >2s

6us

Pulldown >20ms

PWRKEY

(INPUT)

Figure 13: Timing of restarting system after emergency shutdown

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3.5. Charge interface

M50 provides charging function for rechargeable Li-Ion or Lithium Polymer battery. It is

introduced simply in this document. If customer wants to get more information about charging,

please refer to the document [13].

Table 8: Pin definition of the charging

Name Pin I/O Description.

GATDRV 74 O Charge driving

CHGLDO 73 I Charger power supply source

CHGDET 72 I Charger detection

ISENSE 71 I Current sense

B AT S N S 70 I VBAT voltage sense

3.6. Power saving

Upon system requirement, there are several actions to drive the module to enter low current

consumption status. For example, “AT+CFUN” can be used to set module into minimum

functionality mode and DTR hardware interface signal can be used to lead system to SLEEP

mode.

3.6.1. Minimum functionality mode

Minimum functionality mode reduces the functionality of the module to a minimum level, thus

minimize the current consumption when the slow clocking mode is activated at the same time.

This mode is set with the “AT+CFUN” command which provides the choice of the functionality

levels <fun>=0, 1, 4.

 0: minimum functionality

 1: full functionality (default)

 4: disable both transmitting and receiving of RF part

If the module is set to minimum functionality by “AT+CFUN=0”, the RF function and SIM card

function would be disabled. In this case, the UART port is still accessible, but all AT commands

correlative with RF function or SIM card function will be not accessible.

If the module has been set by “AT+CFUN=4”, the RF function will be disabled, the UART port is

still active. In this case, all AT commands correlative with RF function will be not accessible.

After the module is set by “AT+CFUN=0” or “AT+CFUN=4”, it can return to full functionality by

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“AT+CFUN=1”.

For detailed information about “AT+CFUN”, please refer to the document [1].

3.6.2. SLEEP mode

The SLEEP mode is disabled in default firmware configuration. Customer’s application can

enable this mode by “AT+QSCLK=1”. On the other hand, the default setting is “AT+QSCLK=0”

and in this mode, the module cannot enter SLEEP mode.

When “AT+QSCLK=1” is sent to the module, customer’s application can control the module to

enter or exit from the SLEEP mode through pin DTR. When DTR is set to high level, and there is

no on-air or hardware interrupt such as GPIO interrupt or data on UART port, the module will

enter SLEEP mode automatically. In this mode, the module can still receive voice, SMS or GPRS

paging from network but the UART port is not accessible.

3.6.3. Wake up module from SLEEP mode

When the module is in the SLEEP mode, the following methods can wake up the module.

 If the DTR Pin is set low, it would wake up the module from the SLEEP mode. The UART

port will be active within 20ms after DTR is changed to low level.

 Receive a voice or data call from network wakes up module.

 Receive an SMS from network wakes up module.

Note: DTR pin should be held at low level during communication between the module and

DTE.

3.7. Summary of state transition

Table 9: Summary of state transition

Current mode Next mode

Power down Normal mode SLEEP mode

Power down Use PWRKEY

Normal mode AT+QPOWD, use

PWRKEY pin, or use

EMERG_OFF pin

Use AT command

“AT+QSCLK=1” and pull

DTR up

SLEEP mode Use PWRKEY pin, or

use EMERG_OFF pin

Pull DTR down or

incoming call or

SMS or GPRS

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3.8. RTC backup

The RTC (Real Time Clock) can be supplied by an external capacitor or battery (rechargeable or

non-chargeable) through the pin VRTC. A 1.5K resistor has been integrated in the module for

current limiting. A coin-cell battery or a super-cap can be used to backup power supply for RTC.

The following figures show various sample circuits for RTC backup.

Module

RTC Core

1.5K

VRTC

Non-chargeable

Backup Battery

Figure 14: RTC supply from non-chargeable battery

VRTC

Rechargeable

Backup Battery

Module

RTC Core

1.5K

Figure 15: RTC supply from rechargeable battery

VRTC

Large Capacitance

Capacitor

Module

RTC Core

1.5K

Figure 16: RTC supply from capacitor

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Coin-type rechargeable capacitor such as XH414H-IV01E from Seiko can be used.

Figure 17: Seiko XH414H-IV01E Charge Characteristics

3.9. Serial interfaces

The module provides three serial ports: UART Port, Debug Port and Auxiliary UART Port. The

module is designed as a DCE (Data Communication Equipment), following the traditional

DCE-DTE (Data Terminal Equipment) connection. Autobauding function supports baud rate from

4800bps to 115200bps.

The UART Port:

 TXD: Send data to RXD of DTE.

 RXD: Receive data from TXD of DTE.

 RTS: Request to send.

 CTS: Clear to send.

 DTR: DTE is ready and inform DCE (this pin can wake the module up).

 RI: Ring indicator (when the call, SMS, data of the module are coming, the module will

output signal to inform DTE).

 DCD: Data carrier detection (the validity of this pin demonstrates the communication link is

set up).

Note: The module disables hardware flow control by default. When hardware flow control is

required, RTS and CTS should be connected to the host. AT command “AT +IFC=2,2” is used to

enable hardware flow control. AT command “AT+IFC=0,0” is used to disable the hardware

flow control. For more details, please refer to the document [1].

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The Debug Port

 DBG_TXD: Send data to the COM port of computer.

 DBG_RXD: Receive data from the COM port of computer.

The Auxiliary U ART Port

 TXD_AUX: Send data to the RXD of DTE.

 RXD_AUX: Receive data from the TXD of DTE.

The logic levels are described in the following table.

Table 10: Logic levels of the UART interfaces

Parameter Min Max Unit

VIL 0 0.25×VDD_EXT V

VIH 0.75×VDD_EXT VDD_EXT +0.3 V

VOL 0.15×VDD_EXT V

VOH 0.85×VDD_EXT V

Table 11: Pin definition of the UART interfaces

Interface Name Pin Description

Debug Port DBG_RXD 43 Receive data of the debug port

DBG_TXD 42 Transmit data of the debug port

UART Port

RI 46 Ring indicator

RTS 51 Request to send

CTS 48 Clear to send

RXD 50 Receive data of the UART port

TXD 49 Transmit data of the UART port

DTR 47 Data terminal ready

DCD 45 Data carrier detection

Auxiliary UART Port RXD_AUX 41 Receive data of the Auxiliary UART

TXD_AUX 40 Transmit data of the Auxiliary UART

3.9.1. UART Port

3.9.1.1. The features of UART Port.

 Seven lines on U A RT interface

 Contain data lines TXD and RXD, hardware flow control lines RTS and CTS, other control

lines DTR, DCD and RI.

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 Used for AT command, GPRS data, etc. Multiplexing function is supported on the UART

Port. So far only the basic mode of multiplexing is available.

 Support the communication baud rates as the following:

300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600, 115200.

 The default setting is autobauding mode. Support the following baud rates for Autobauding

function:

4800, 9600, 19200, 38400, 57600, 115200.

 The module disables hardware flow control by default. AT command “AT+IFC=2,2” is used

to enable hardware flow control.

After setting a fixed baud rate or autobauding, please send “AT ” string at that rate. The UART port

is ready when it responds “OK”.

Autobauding allows the module to detect the baud rate by receiving the string “AT ” or “at” from

the host or PC automatically, which gives module flexibility without considering which baud rate

is used by the host controller. Autobauding is enabled by default. To take advantage of the

autobauding mode, special attention should be paid according to the following requirements:

Synchronization between DTE and DCE:

When DCE (the module) powers on with the autobauding enabled, it is recommended to wait 2 to

3 seconds before sending the first AT character. After receiving the “OK” response, DTE and

DCE are correctly synchronized.

If the host controller needs URC in the mode of autobauding, it must be synchronized firstly.

Otherwise the URC will be discarded.

Restrictions on autobauding operation:

 The UART port has to be operated at 8 data bits, no parity and 1 stop bit (factory setting).

 The “At” and “aT” commands cannot be used.

 Only the strings “AT ” or “at” can be detected (neither “At” nor “aT”).

 The Unsolicited Result Codes like “RDY”, “+CFUN: 1” and “+CPIN: READY” will not be

indicated when the module is turned on with autobauding enabled and not be synchronized.

 Any other Unsolicited Result Codes will be sent at the previous baud rate before the module

detects the new baud rate by receiving the first “AT ” or “at” string. The DTE may receive

unknown characters after switching to new baud rate.

 It is not recommended to switch to autobauding from a fixed baud rate.

 If autobauding is active it is not recommended to switch to multiplex mode.

Note: To assure reliable communication and avoid any problems caused by undetermined baud

rate between DCE and DTE, it is strongly recommended to configure a fixed baud rate and save

it instead of using autobauding after start-up. For more details, please refer to the Section

“AT+IPR” in document [1].

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3.9.1.2. The connection of UART

The connection between module and host using UART Port is very flexible. Three connection

styles are illustrated as below.

Reference design for Full-Function U A RT connection is shown as below when it is applied in

modulation-demodulation.

TXD

RXD

RTS

CTS

DTR

DCD

RI

TXD

RXD

RTS

CTS

DTR

DCD

RING

Module (DCE)

Serial portUART port

GND GND

PC (DTE)

Figure 18: Reference design for Full-Function UART

Three-line connection is shown as below.

TXD

RXD

GND

UART port

RTS

0R

TXD

RXD

GND

Module (DCE) Host (DTE)

Controller

Figure 19: Reference design for UART Port

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UART Port with hardware flow control is shown as below. This connection will enhance the

reliability of the mass data communication.

RTS

CTS

RTS

CTS

GND

RXD

TXD TXD

RXD

GND

Module (DCE) Host (DTE)

Controller

Figure 20: Reference design for UART Port with hardware flow control

3.9.1.3. Firmware upgrade

The TXD, RXD can be used to upgrade firmware. The PWRKEY pin must be pulled down before

the firmware upgrade. Please refer to the following figure for Firmware upgrade.

IO Connector

TXD

RXD

GND

PWRKEY

Module (DCE)

UART port

TXD

RXD

GND

PWRKEY

Figure 21: Reference design for Firmware upgrade

Note: The firmware of module might need to be upgraded due to certain reasons, it is

recommended to reserve these pins in the host board for firmware upgrade. For detailed design,

please refer to the document [11].

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3.9.2. Debug Port

Debug Port

 Two lines: DBG_TXD and DBG_RXD

 It outputs log information automatically.

 Debug Port is only used for firmware debugging and its baud rate must be configured as

460800bps.

Computer

TXD

RXD

GND

Module (DCE)

Debug port

DBG_TXD

DBG_RXD

GND

Figure 22: Reference design for Debug Port

3.9.3. Auxiliary UART Port

Auxiliary UART Port

 Two data lines: TXD_AUX and RXD_AUX

 Auxiliary UART port is used for AT command only and does not support GPRS data, CSD

FAX, Multiplexing function etc.

 Auxiliary U ART port supports the communication baud rates as the following:

4800, 9600, 14400, 19200, 28800, 38400, 57600, 115200.

 The default baud rate setting is 115200bps, and does not support autobauding. The baud rate

can be modified by AT+QSEDCB command. For more details, please refer to the document

[1].

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Module (DCE) Host (DTE)

Controller

TXD

RXD

GND

TXD_AUX

RXD_AUX

GND

Figure 23: Reference design for Auxiliary UART port

3.9.4. UART application

The reference design of 3.3V level match is shown as below. If the host is a 3V system, please

change the 5.6K resistor to 15K.

MCU/ARM

/TXD

/RXD

1K

TXD

RXD

RTS

CTS

DTR

RI

/RTS

/CTS

GPIO

EINT

GPIO DCD

Module

1K

Voltage level:3.3V

5.6K

1K

GND GND

Figure 24: Level match design for 3.3V system

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The reference design for 5V level match is shown as below. The connection of dotted line can be

referred to the connection of solid line. Please pay attention to the direction of signal. Input dotted

line of module should be referred to input solid line of the module. Output dotted line of module

should be referred to output solid line of the module.

As to the circuit below, VDD_EXT supplies power for the I/O of module, while VCC_MCU

supplies power for the I/O of the MCU/ARM.

MCU/ARM

/TXD

/RXD

VDD_EXT

4.7K

VCC_MCU

4.7K

5.6K

4.7K

VDD_EXT

TXD

RXD

RTS

CTS

DTR

RI

/RTS

/CTS

GND

GPIO DCD

Module

GPIO

EINT

VCC_MCU

Voltage level: 5V

4.7K

GND

Figure 25: Level match design for 5V system

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The following circuit shows a reference design for the communication between module and PC.

Since the electrical level of module is 2.8V, so a RS-232 level shifter must be used.

9

8

7

6

5

4

3

2

1

15

14

8

9

11

12

5

7

6

10

4

26

2

27

13

18

20

21

16

17

19

22

23

24

3

1

25

28

GND

SP3238

3V

GND

T5OUT

/ SHUTDOWN

V+

GND

V-

VCC

T4OUT

T2OUT

T3OUT

T1OUT

R3I N

R2I N

R1I N

/ STATUS

3V ONLINE

R1OUT

R2OUT

R3OUT

/ R1OUT

GND T5IN

T4I N

T3I N

T2I N

T1I N

C2+

C2-

C1-

C1+

MODULE

RXD

DTR

RTS

RI

CTS

TXD

DCD

To PC serial port

Figure 26: Level match design for RS-232

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3.10. Audio interfaces

The module provides two analogy input channels and three analogy output channels.

Table 12: Pin definition of Audio interfaces

AIN1 and AIN2 can be used for input of microphone and line. An electret microphone is usually

used. AIN1 and AIN2 are both differential input channels.

AOUT1 is used for output of the receiver. This channel is typically used for a receiver built into a

handset. AOUT1 channel is a differential channel.

AOUT2 is typically used with earphone. It is a single-ended and mono channel. SPK2P and

AGND can establish a pseudo differential mode.

AOUT3 is used for loud speaker output as it embedded an amplifier of class AB whose maximum

drive power is 800mW.

All of these three audio channels support voice and ringtone output, and so on, and can be

swapped by “AT+QAUDCH” command. For more details, please refer to the document [1].

Use AT command “AT+QAUDCH” to select audio channel:

 0--AIN1/AOUT1, the default value is 0.

 1--AIN2/AOUT2

 2--AIN2/AOUT3

For each channel, customer can use AT+QMIC to adjust the input gain level of microphone.

Customer can also use “AT+CLVL” to adjust the output gain level of receiver and speaker.

“AT+QSIDET” is used to set the side-tone gain level. For more details, please refer to the

document [1].

Interface Name Pin Description

AIN1/AOUT1

MIC1P 9 Channel one for Microphone positive input

MIC1N 10 Channel one for Microphone negative input

SPK1P 12 Channel one for Audio positive output

SPK1N 11 Channel one for Audio negative output

AIN2/AOUT2

MIC2P 7 Channel two for Microphone positive input

MIC2N 8 Channel two for Microphone negative input

SPK2P 5 Channel two for Audio positive output

AGND 6 Analog ground.

AOUT3

LOUDSPKP 14 Channel three for Audio positive output

LOUDSPKN 13 Channel three for Audio negative output

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Table 13: AOUT3 output characteristics

Parameter Condition Min Typ Max Unit

RMS power 8ohm load

VBAT=4.3V

THD+N=1%

800 mW

8ohm load

VBAT=3.7V

THD+N=1%

700 mW

Gain adjustment range 0 18 dB

Gain adjustment steps 3 dB

3.10.1. Decrease TDD noise and other noise

The 33pF capacitor is applied for filtering out 900MHz RF interference when the module is

transmitting at GSM900MHz. Without placing this capacitor, TDD noise could be heard.

Moreover, the 10pF capacitor here is for filtering out 1800MHz RF interference. However, the

resonant frequency point of a capacitor largely depends on the material and production technique.

Therefore, customer would have to discuss with its capacitor vendor to choose the most suitable

capacitor for filtering out GSM850MHz, GSM900MHz, DCS1800MHz and PCS1900MHz

separately.

The severity degree of the RF interference in the voice channel during GSM transmitting period

largely depends on the application design. In some cases, GSM900 TDD noise is more severe;

while in other cases, DCS1800 TDD noise is more obvious. Therefore, customer can have a

choice based on test results. Sometimes, even no RF filtering capacitor is required.

The capacitor which is used for filtering out RF noise should be close to RJ11 or other audio

interfaces. Audio alignment should be as short as possible.

In order to decrease radio or other signal interference, the position of RF antenna should be kept

away from audio interface and audio alignment. Power alignment and audio alignment should not

be parallel, and power alignment should be far away from audio alignment.

The differential audio traces have to be placed according to the differential signal layout rule.

3.10.2. Microphone interfaces design

AIN1 and AIN2 channels come with internal bias supply for external electret microphone. A

reference circuit is shown in the following figure.

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Close to Microphone

MICxP

MICxN

GND

Differential layout

Module

Electret

Microphone

GND

GND GND

GND

ESD

10pF

0603

10pF

0603

10pF

0603

33pF

0603

33pF

0603

33pF

0603

Figure 27: Reference design for AIN1&AIN2

3.10.3. Receiver and speaker interface design

SPK1P

SPK1N

Differential layout 10pF

0603

10pF

0603

33pF

0603

33pF

0603

33pF

0603

Close to Speaker

GND

10pF

0603

ESD

Module

Figure 28: Reference design for AOUT1

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SPK2P

AGND

Differential layout

10pF

0603

33pF

0603

Close to Speaker

GND

ESD

Module

22uF

Figure 29: Handset interface design for AOUT2

Module

SPK2P

AGND

Differential layout

Amplifier

circuit

10pF

0603

10pF

0603

33pF

0603

33pF

0603

Close to Speaker

GND

ESD

C2

C1

Figure 30: Speaker interface design with an amplifier for AOUT2

Texas Instrument’s TPA6205A1is recommended for a suitable differential audio amplifier. There

are plenty of excellent audio amplifiers in the market.

Note: The value of C1 and C2 here depends on the input impedance of audio amplifier.

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3.10.4. Earphone interface design

Amphenol

9001-8905-050

1

2

4

3

SPK2P

MIC2N

MIC2P

22uF

68R

GND GND

AGND

Close to Socket

Differential layout

AGND

GND GND

GND

AGND

Module

4.7uF

33pF

0603

10pF

0603

33pF

0603

10pF

0603 ESD

ESD

Figure 31: Earphone interface design

3.10.5. Loud speaker interface design

LOUDSPKP

LOUDSPKN

Differential layout 10pF

10pF 33pF

33pF

Close to Speaker

GND

100pF

ESD

Module

0R

0603

0603 0603

0603

Figure 32: Loud speaker interface design

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3.10.6. Audio characteristics

Table 14: Typical electret microphone characteristics

Parameter Min Typ Max Unit

Working Voltage 1.2 1.5 2.0 V

Working Current 200 500 uA

External Microphone Load Resistance 2.2 kOhm

Table 15: Typical speaker characteristics

Parameter Min Typ Max Unit

Normal

Output

(AOUT1)

Single

Ended

Load

Resistance

28 32 Ohm

Ref level 0 2.4 Vpp

Differential Load

Resistance

28 32 Ohm

Ref level 0 4.8 Vpp

Auxiliary

Output

(AOUT2)

Single

Ended

Load

Resistance

16

32 Load

Resistance

Ref level 0 2.4 Vpp

Output

(AOUT3) Differential

Load

Resistance

8 Load

Resistance

Ref level 0 2×V B AT Vpp

3.11. SIM card interface

3.11.1. SIM card application

The SIM interface supports the functionality of the GSM Phase 1 specification and also supports

the functionality of the new GSM Phase 2+ specification for FAST 64 kbps SIM card, which is

intended for use with a SIM application Tool-kit.

The SIM interface is powered from an internal regulator in the module. Both 1.8V and 3.0V SIM

Cards are supported.

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Table 16: Pin definition of the SIM interface

In Figure 33, the pin SIM_PRESENCE is used to detect whether the tray of the Molex SIM socket,

which is used for holding SIM card, is present in the card socket. When the tray is inserted in the

socket, SIM_PRESENCE is at low level. Regardless of whether the SIM card is in the tray or not,

the change of SIM_PRESENCE level from high to low level inspires the module to reinitialize

SIM card. In default configuration, SIM card detection function is disabled. Customer’s

application can use “AT+QSIMDET=1,0 ” to switch on and “AT+QSIMDET=0,0 ” to switch off

the SIM card detection function. For detail of this AT command, please refer to the document [1].

When “AT+QSIMDET=1,0” is set and the tray with SIM card is removed from SIM socket, the

following URC will be presented.

+CPIN: NOT READY

When the tray with SIM card is inserted into SIM socket again and the module finishes

re-initialization SIM card, the following URC will be presented.

Call Ready

Module

SIM_VDD

SIM_GND

SIM_RST

SIM_CLK

SIM_DATA

SIM_PRESENCE

22R

VDD_EXT

10K

100nF SIM_Holder

GND

ESDA6V8V6

33pF33pF 33pF 33pF

VCC

RST

CLK IO

VPP

GND

Figure 33: Reference circuit of the 8 pins SIM card

Name Pin Description

SIM_VDD 56 Supply power for SIM Card. Automatic detection of

SIM card voltage. 3.0V±10% and 1.8V±10%.

Maximum supply current is around 10mA.

S I M _ D ATA 54 SIM data

SIM_CLK 55 SIM clock

SIM_RST 53 SIM reset

SIM_PRESENCE 57 SIM card detection

SIM_GND 52 SIM ground

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Note: Please do not use “AT+QSIMDET=1,1” which causes to initialize SIM card when Figure

33 circuit is adopted.

If customer does not need the SIM card detection function, keep SIM_PRESENCE open. The

reference circuit using a 6-pin SIM card socket is illustrated as the following figure.

Module

SIM_VDD

SIM_GND

SIM_RST

SIM_CLK

SIM_DATA

SIM_PRESENCE

22R

100nF SIM_Holder

GND

ESDA6V8V6

33pF

33pF 33pF 33pF

VCC

RST

CLK IO

VPP

GND

Figure 34: Reference circuit of the 6 pins SIM card

In order to enhance the reliability and availability of the SIM card in the customer’s application.

Please follow the below criterion in the SIM circuit design.

 Keep layout of SIM card as close as possible to the module. Assure the possibility of the

length of the trace is less than 20cm.

 Keep SIM card signal away from RF and VBAT alignment.

 Assure the ground between module and SIM cassette short and wide. Keep the width of

ground no less than 0.5mm to maintain the same electric potential. The decouple capacitor of

SIM_VDD is less than 1uF and must be near to SIM cassette.

 To avoid cross talk between SIM_DATA and SIM_CLK. Keep them away with each other

and shield them with surrounded ground

 In order to offer good ESD protection, it is recommended to add TVS such as WILL

(http://www.willsemi.com) ESDA6V8AV6. The 22Ω resistors should be added in series

between the module and the SIM card so as to suppress the EMI spurious transmission and

enhance the ESD protection. Please to be noted that the SIM peripheral circuit should be

close to the SIM card socket.

3.11.2. 6 Pin SIM cassette

For 6-pin SIM card holder, it is recommended to use Amphenol C707 10M006 512 2. Please visit

http://www.amphenol.com for more information.

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Figure 35: Amphenol C707 10M006 512 2 SIM card holder

Table 17: Pin description of Amphenol SIM card holder

Name Pin Description

SIM_VDD C1 SIM Card Power Supply

SIM_RST C2 SIM Card Reset

SIM_CLK C3 SIM Card Clock

GND C5 Ground

VPP C6 Not Connect

S I M _ D ATA C7 SIM Card data I/O

3.11.3. 8 Pin SIM cassette

For 8-pin SIM card holder, it is recommended to use Molex 91228. Please visit

http://www.molex.com for more information.

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Figure 36: Molex 91228 SIM card holder

Table 18: Pin description of Molex SIM card holder

Name Pin Description

SIM_VDD C1 SIM Card Power supply

SIM_RST C2 SIM Card Reset

SIM_CLK C3 SIM Card Clock

SIM_PRESENCE C4 SIM Card Presence Detection

GND C5 Ground

VPP C6 Not Connect

S I M _ D ATA C7 SIM Card Data I/O

SIM_DETECT C8 Pulled down GND with external circuit. When the tray is

present, C4 is connected to C8.

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3.12. SD card interface

The module provides SD card interface that support many types of memory, such as Memory

Stick, SD/MCC card and T-Flash or Micro SD card. The following are the main features of SD

card interface.

 Only supports 1bit serial mode.

 Does not support the SPI mode SD/MMC memory card.

 Does not support hot plug.

 Up to 26MHz data rate in serial mode.

 Up to 32GB maximum memory card capacity.

With interface features and reference circuit of SD card shown in Figure 37, the users can easily

design the SD card application circuit to enhance the memory capacity of the module. The module

can record and store the audio files to the SD card, and play the audio files from SD card as well.

Table 19: Pin definition of the SD card interface

Module

SD_DATA0

SD_CLK

SD_CMD

DATA2

DATA1

DATA0

CD/DATA3

CMD

VDD

CLK

VSS

47K

47K 47K

4.7uF 0.1nF

VDD_EXT

33R

Micro SD Socket

1

2

3

4

5

6

7

8

Figure 37: Reference circuit of SD card

Name Pin Description

SD_DATA0 36 SD data

SD_CLK 35 SD clock

SD_CMD 34 SD command

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Table 20: Pin name of the SD card and Micro SD card

In SD card interface designing, in order to ensure good communication performance with SD card,

the following design principles should be complied with.

 Route SD card trace as short as possible. Keep total trace length < 100mm, and trace

difference of DATA0, CMD, and CLK to be < 10mm. The SD_CLK and SD_DATA0 line

must be shielded by GND in order to avoid interference.

 In order to offer good ESD protection, it is recommended to add TVS on signals with the

capacitance is less than 15pF.

 Reserve external pull-up resistor for other data lines except the DATA0.

Pin NO. Pin name of SD card Pin name of T-Flash(Micro SD) card

1 CD/DATA3 DATA2

2 CMD CD/DATA3

3 VSS1 CMD

4 VDD VDD

5 CLK CLK

6 VSS2 VSS

7 DATA0 DATA0

8 DATA1 DATA1

9 DATA2

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3.13. PCM interface

M50 supports PCM interface. It is used for digital audio transmission between the module and the

customer’s device. This interface is composed of PCM_CLK, PCM_SYNC, PCM_IN and

PCM_OUT signal lines.

Pulse-code modulation (PCM) is a converter that changes the consecutive analog audio signal to

discrete digital signal. The whole procedure of Pulse-code modulation contains sampling,

quantizing and encoding.

Table 21: Pin definition of PCM interface

Name Pin I/O Description

PCM_CLK 19 O PCM clock

PCM_IN 18 I PCM data input

PCM_OUT 20 O PCM data output

PCM_SYNC 21 O PCM frame synchronization

3.13.1. Configuration

M50 supports 16 bits line code PCM format. The sample rate is 8 KHz, the clock source is 256

KHz, and the module can only act as master mode. The PCM interfaces support long and short

synchronization simultaneously. It only supports MSB first. For more detailed information, please

see the table below.

Table 22: Configuration

PCM

Line interface format Linear

Data length Linear: 16 bits

Sampling rate 8KHz

PCM clock/synchronization

source

PCM master mode: clock and synchronization is generated

by module

PCM synchronization rate 8KHz

PCM clock rate PCM master mode:256 KHz

PCM synchronization format Long/short synchronization

PCM data ordering MSB first

Zero padding Yes

Sign extension Yes

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3.13.2. Timing

The sample rate of the PCM interface is 8 KHz and the clock source is 256 KHz, so every frame

contains 32 bits data, since M50 supports 16 bits line code PCM format, the left 16 bits are invalid.

The following diagram shows the timing of different combinations. The synchronization length in

long synchronization format can be programmed by firmware from one bit to eight bits. In the

Sign extension mode, the high three bits of 16 bits are sign extension, and in the Zero padding

mode, the low three bits of 16 bits are zero padding.

12 11 10 9 8 7 6 5 4 3 2 1 0

PCM_CLK

PCM_SYNC

PCM_OUT

PCM_IN

MSB

Sign extension

Figure 38: Long synchronization & Sign extension diagram

12 11 10 9 8 7 6 5 4 3 2 1 0

PCM_CLK

PCM_SYNC

PCM_OUT

PCM_IN

MSB

Zero padding

Figure 39: Long synchronization & Zero padding diagram

PCM_CLK

PCM_SYNC

PCM_OUT

PCM_IN

12 11 10 9 8 7 6 5 4 3 2 1 0

MSB

Sign extension

Figure 40: Short synchronization & Sign extension diagram

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PCM_CLK

PCM_SYNC

PCM_OUT

PCM_IN

12 11 10 9 8 7 6 5 4 3 2 1 0

MSB

Zero padding

Figure 41: Short synchronization & Zero padding diagram

3.13.3. Reference design

As M50 only acts as a master, the module provides synchronization and clock source. The

reference design is shown as below.

PCM_SYNC

PCM_CLK

PCM_OUT

PCM_IN

PCM_SYNC

PCM_CLK

PCM_IN

PCM_OUT

Module

(master)

Codec

(slave)

GND GND

Figure 42: Reference design for PCM

3.13.4. AT command

There are two AT commands about the configuration of PCM are listed as below.

“AT+QPCMON” can configure operating mode of PCM.

AT+QPCMON= mode,Sync_Type,Sync_Length,SignExtension,MSBFirst

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Table 23: QPCMON command description

Parameter scope Description

Mode 0~2 0: Close PCM

1: Open PCM

2: Open PCM when audio talk is set up

Sync_Type 0~1 0: Short synchronization

1: Long synchronization

Sync_Length 1~8 Programmed from one bit to eight bit

SignExtension 0~1 0: Zero padding

1: Sign extension

MSBFirst 0~1 0: MSB first

1: Not supported

“AT+QPCMVOL” can configure volume of input and output.

AT+QPCMVOL=vol_pcm_in,vol_pcm_out

Table 24: QPCMVOL command description

Parameter scope Description

vol_pcm_in 0~32767 Set the input volume

vol_pcm_out 0~32767 Set the output volume

The voice may be distorted when this

value exceeds 16384.

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3.14. ADC

The module provides two ADC channel to measure the value of voltage. Please give priority to the

use of ADC0 channel. The command “AT+QADC” can read the voltage value applied on ADC0

pin, while AT command “AT+QEADC” can read the voltage value applied on ADC1 pin. For

details of this AT command, please refer to the document [1]. In order to improve the accuracy of

ADC, the layout of ADC should be surrounded by ground.

Table 25: Pin definition of the ADC

Name Pin Description

ADC0 2 General purpose analog to digital converter

ADC1 1 General purpose analog to digital converter

Table 26: Characteristics of the ADC

Parameter Min Typ Max Unit

Voltage Range 0 2.8 V

ADC Resolution 10 bit

ADC Accuracy 2.7 mV

3.15. Behaviors of the RI

Table 27: Behaviors of the RI

State RI response

Standby HIGH

Voice calling Change to LOW, then:

1. Change to HIGH when call is established.

2. Use ATH to hang up the call, RI changes to HIGH.

3. Calling part hangs up, RI changes to HIGH first, and changes to LOW for

120ms indicating “NO CARRIER” as an URC, then changes to HIGH

again.

4. Change to HIGH when SMS is received.

Data calling Change to LOW, then：

1. Change to HIGH when data connection is established.

2. U s e AT H t o hang up the data calling, RI changes to HIGH.

3. Calling part hangs up, RI changes to HIGH first, and changes to LOW for

120ms indicating “NO CARRIER” as an URC, then changes to HIGH

again.

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4. Change to HIGH when SMS is received.

SMS When a new SMS comes, the RI changes to LOW and holds low level for

about 120 ms, then changes to HIGH.

URC Certain URCs can trigger 120ms low level on RI. For more details, please

refer to the document [1]

If the module is used as a caller, the RI would maintain high except the URC or SMS is received.

On the other hand, when it is used as a receiver, the timing of the RI is shown below.

RI

Idle Ring

Off-hook by“ATA”

On-hook by “ATH”

SMS received

HIGH

LOW

Figure 43: RI behavior of voice calling as a receiver

RI

Idle Ring

Data calling establish

SMS received

HIGH

LOW On-hook by “ATH”

Figure 44: RI behavior of data calling as a receiver

RI

Idle Calling On-hook

Talking

HIGH

LOW

Idle

Figure 45: RI behavior as a caller

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RI

Idle or

Talking

URC or

SMS received

HIGH

LOW

120ms

Figure 46: RI behavior of URC or SMS received

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3.16. Network status indication

The NETLIGHT signal can be used to drive a network status indicator LED. The working state of

this pin is listed in the following table.

Table 28: Working state of the NETLIGHT

State Module function

Off The module is not running.

64ms On/ 800ms Off The module is not synchronized with network.

64ms On/ 2000ms Off The module is synchronized with network.

64ms On/ 600ms Off GPRS data transfer is ongoing.

A reference circuit is shown as below.

Module

300R

4.7K

47K

VBAT

NETLIGHT

Figure 47: Reference design for NETLIGHT

3.17. Operating status indication

The STATUS pin is set as an output pin and can be used to judge whether module is power-on. In

customer’s design, this pin can be connected to a GPIO of DTE or be used to drive an LED in

order to judge the module’s operation status. A reference circuit is shown in Figure 48.

Table 29: Pin definition of the STATUS

Name Pin Description

S TAT U S 16 Indicate module operating status

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Module

300R

4.7K

47K

VBAT

STATUS

Figure 48: Reference design for STATUS

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4. Antenna interface

The Pin 63 is the RF antenna pad. The RF interface has an impedance of 50Ω.

Table 30: Pin definition of the RF_ANT

4.1. RF reference design

The reference design for RF is shown as below.

Module

RF_ANT

0R

NM NM

Figure 49: Reference design for RF

M50 provides an RF antenna pad for customer’s antenna connection. The RF trace in host PCB

connected to the module RF antenna pad should be micro-strip line or other types of RF trace,

whose characteristic impedance should be close to 50Ω. M50 comes with grounding pads which

are next to the antenna pad in order to give a better grounding. Besides, a ∏ type match circuit is

suggested to be used to adjust the RF performance.

To minimize the loss on the RF trace and RF cable, take design into account carefully. It is

recommended that the insertion loss should meet the following requirements:

Name Pin Description

GND 61 Ground

GND 62 Ground

RF_ANT 63 RF antenna pad

GND 64 Ground

GND 65 Ground

GND 66 Ground

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 GSM850/EGSM900 is <1dB.

 DCS1800/PCS1900 is <1.5dB.

4.2. RF output power

Table 31: The module conducted RF output power

Frequency Max Min

GSM850 32.5dBm ±1dB 5dBm±5dB

EGSM900 32.5dBm ±1dB 5dBm±5dB

DCS1800 29.5dBm ±1dB 0dBm±5dB

PCS1900 29.5dBm ±1dB 0dBm±5dB

Note: In GSM850&EGSM900 GPRS 4 slots TX mode, the max output power is reduced by

2.5dB. This design conforms to the GSM specification as described in section 13.16 of 3GPP TS

51.010-1.

4.3. RF receiving sensitivity

Table 32: The module conducted RF receiving sensitivity

Frequency Receive sensitivity

GSM850 < -108.5dBm

EGSM900 < -108.5dBm

DCS1800 < -108.5dBm

PCS1900 < -108.5dBm

4.4. Operating frequencies

Table 33: The module operating frequencies

Frequency Receive Transmit ARFCH

GSM850 869~894MHz 824~849MHz 128~251

EGSM900 925~960MHz 880~915MHz 0~124, 975~1023

DCS1800 1805~1880MHz 1710~1785MHz 512~885

PCS1900 1930~1990MHz 1850~1910MHz 512~810

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4.5. RF cable soldering

Soldering the RF cable to RF pad of module correctly will reduce the loss on the path of RF,

please refer to the following example of RF soldering.

Figure 50: RF soldering sample

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5. Electrical, reliability and radio characteristics

5.1. Absolute maximum ratings

Absolute maximum ratings for power supply and voltage on digital and analog pins of module are

listed in the following table:

Table 34: Absolute maximum ratings

Parameter Min Max Unit

V B AT -0.3 +4.73 V

Peak current of power supply 0 2 A

RMS current of power supply (during one TDMA- frame) 0 0.7 A

Voltage at digital pins -0.3 3.3 V

Voltage at analog pins -0.3 3.0 V

Voltage at digital/analog pins in power down mode -0.25 0.25 V

5.2. Operating temperature

The operating temperature is listed in the following table:

Table 35: Operating temperature

Parameter Min Typ Max Unit

Normal Temperature -35 +25 +80 ℃

Restricted Operation1) -40 ~ -35 +80 ~ +85 ℃

Storage Temperature -45 +90 ℃

1

）

When the module works in this temperature range, the deviation from the GSM specification

may occur. For example, the frequency error or the phase error will be increased.

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5.3. Power supply ratings

Table 36: The module power supply ratings

Parameter Description Conditions Min Typ Max Unit

VBAT Supply

voltage

Voltage must stay within the

min/max values, including

voltage drop, ripple, and spikes.

3.3 4.0 4.6 V

Vdrop during

transmitting

burst

Maximum power control level

on GSM850 and GSM900.

400 mV

Voltage

ripple

Maximum power control level

on GSM850 and GSM900

@ f<200kHz

@ f>200kHz

50

2

mV

IVBAT

Average

supply

current

Power down mode

SLEEP mode @ DRX=5

30

1.3

uA

mA

Minimum functionality mode

AT+CFUN=0

IDLE mode

SLEEP mode

AT+CFUN=4

IDLE mode

SLEEP mode

13

0.98

13

1.0

mA

IDLE mode

GSM850/EGSM 900

DCS1800/PCS1900

13

mA

TALK mode

GSM850/EGSM 9001)

DCS1800/PCS19002)

209/208

191/202

mA

DATA mode, GPRS (3 Rx,2Tx)

GSM850/EGSM 9001)

DCS1800/PCS19002)

435/400

313/337

mA

DATA mode, GPRS(2 Rx,3Tx)

GSM850/EGSM 9001)

DCS1800/PCS19002)

605/558

399/460

mA

DATA mode, GPRS (4 Rx,1Tx)

GSM850/EGSM 9001)

DCS1800/PCS19002)

265/240

200/212

mA

DATA mode, GPRS

(1Rx,4Tx)

GSM850/EGSM 9001)

615/560

mA

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DCS1800/PCS1900

2)

420/470 mA

Peak supply

current

(during

transmission

slot)

Maximum power control level

on GSM850 and GSM900.

1.6 1.8 A

1) Power control level PCL 5

2) Power control level PCL 0

5.4. Current consumption

The values of current consumption are shown as below.

Table 37: The module current consumption

Condition Current Consumption

Voice Call

GSM850 @power level #5 <300mA,Typical 209mA

@power level #12,Typical 96mA

@power level #19,Typical 73mA

GSM900 @power level #5 <300mA,Typical 208mA

@power level #12,Typical 96mA

@power level #19,Typical 73mA

DCS1800 @power level #0 <250mA,Typical 191mA

@power level #7,Typical 93mA

@power level #15,Typical 70mA

PCS1900 @power level #0 <250mA,Typical 202mA

@power level #7,Typical 95mA

@power level #15,Typical 71mA

GPRS Data

DATA mode, GPRS ( 1 Rx,1 Tx ) CLASS 12

GSM850 @power level #5 <350mA,Typical 199mA

@power level #12,Typical 87mA

@power level #19,Typical 63mA

EGSM 900 @power level #5 <350mA,Typical 200mA

@power level #12,Typical 96mA

@power level #19,Typical 70mA

DCS 1800 @power level #0 <300mA,Typical 184mA

@power level #7,Typical 82mA

@power level #15,Typical 66mA

PCS 1900 @power level #0 <300mA,Typical 192mA

@power level #7,Typical 82mA

@power level #15,Typical 66mA

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DATA mode, GPRS ( 3 Rx, 2 Tx ) CLASS 12

GSM850 @power level #5 <550mA,Typical 435mA

@power level #12,Typical 158mA

@power level #19,Typical 99mA

EGSM 900 @power level #5 <550mA,Typical 400mA

@power level #12,Typical 150mA

@power level #19,Typical 97mA

DCS 1800 @power level #0 <450mA,Typical 313mA

@power level #7,Typical 130mA

@power level #15,Typical 92mA

PCS 1900 @power level #0 <450mA,Typical 337mA

@power level #7,Typical 140mA

@power level #15,Typical 94mA

DATA mode, GPRS ( 2 Rx, 3 Tx ) CLASS 12

GSM850 @power level #5 <640mA,Typical 605mA

@power level #12,Typical 195mA

@power level #19,Typical 107mA

EGSM 900 @power level #5 <600mA,Typical 558mA

@power level #12,Typical 185mA

@power level #19,Typical 106mA

DCS 1800 @power level #0 <490mA,Typical 399mA

@power level #7,Typical 150mA

@power level #15,Typical 94mA

PCS 1900 @power level #0 <480mA,Typical 460mA

@power level #7,Typical 166mA

@power level #15,Typical 98mA

DATA mode, GPRS ( 4 Rx,1 Tx ) CLASS 12

GSM850 @power level #5 <350mA,Typical 265mA

@power level #12,Typical 122mA

@power level #19,Typical 93mA

EGSM 900 @power level #5 <350mA,Typical 240mA

@power level #12,Typical 115mA

@power level #19,Typical 90mA

DCS 1800 @power level #0 <300mA,Typical 200mA

@power level #7,Typical 107mA

@power level #15,Typical 89mA

PCS 1900 @power level #0 <300mA,Typical 212mA

@power level #7,Typical 118mA

@power level #15,Typical 90mA

DATA mode, GPRS ( 1 Rx, 4 Tx ) CLASS 12

GSM850 @power level #5 <660mA,Typical 615mA

@power level #12,Typical 232mA

@power level #19,Typical 118mA

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EGSM 900 @power level #5 <660mA,Typical 560mA

@power level #12,Typical 215mA

@power level #19,Typical 114mA

DCS 1800 @power level #0 <530mA,Typical 420mA

@power level #7,Typical 173mA

@power level #15,Typical 97mA

PCS 1900 @power level #0 <530mA,Typical 470mA

@power level #7,Typical 192mA

@power level #15,Typical 101mA

Note: GPRS Class 12 is the default setting. The module can be configured from GPRS Class 1

to Class 12 by “AT+QGPCLASS”. Setting to lower GPRS class would make it easier to design

the power supply for the module.

5.5. Electro-static discharge

Although the GSM engine is generally protected against Electrostatic Discharge (ESD), ESD

protection precautions should still be emphasized. Proper ESD handling and packaging procedures

must be applied throughout the processing, handling and operation of any applications using the

module.

The measured ESD values of module are shown in the following table.

Table 38: The ESD endurance (Temperature:25℃,Humidity:45 %)

Tested point Contact

discharge

Air discharge

V B AT,GND ±5KV ±10KV

RF_ANT ±5KV ±10KV

PWRKEY

S TAT U S ±2KV ±4KV

SIM_VDD, SIM_DATA

SIM_CLK, SIM_RST ±2KV ±4KV

TXD, RXD

RTS, CTS, DTR ±2KV ±4KV

Others ±0.5KV ±1KV

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6. Mechanical dimensions

This chapter describes the mechanical dimensions of the module.

6.1. Mechanical dimensions of module

Figure 51: M50 top and side dimensions

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Figure 52: M50 bottom dimensions

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6.2. Recommended footprint without bottom centre pads

silkscreen

frame line

Figure 53: Recommended footprint without bottom centre pads

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6.4. Top view of the module

Figure 54: Top view of the module

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6.5. Bottom view of the module

Figure 55: Bottom view of the module

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7. Storage and manufacturing

7.1. Storage

M50 is distributed in vacuum-sealed bag. The restriction of storage condition is shown as below.

Shelf life in sealed bag: 12 months at <40℃/90% RH

After this bag is opened, devices that will be subjected to reflow solder or other high temperature

process must be:

 Mounted within 72 hours at factory conditions of ≤30℃/60% RH

 Stored at <10% RH

Devices require bake before mounting, if:

 Humidity indicator card is >10% when read at 23℃±5℃

 Mounted exceed 72 hours at factory conditions of ≤30 ℃/60% RH

If baking is required, devices may be baked for 48 hours at 125℃±5℃

Note: As plastic container cannot be subjected to high temperature, devices must be removed

prior to high temperature (125

℃

) bake. If shorter bake times are desired, refer to the

IPC/JEDECJ-STD-033 for bake procedure.

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7.2. Soldering

The squeegee should push the paste on the surface of the stencil that makes the paste fill the

stencil openings and penetrate to the PCB. The force on the squeegee should be adjusted so as to

produce a clean stencil surface on a single pass. To ensure the module soldering quality, the

thickness of stencil at the hole of the module pads should be 0.2mm for M50 .

Figure 56: Paste application

Suggest peak reflow temperature is from 235℃ to 245℃ (for SnAg3.0Cu0.5 alloy). Absolute

max reflow temperature is 260℃. To avoid damage to the module when it was repeatedly heated,

it is suggested that the module should be mounted after the first panel has been reflowed. The

following picture is the actual diagram which we have operated.

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Time(s)

50 100 150 200 250 300

50

100

150

200

250

160℃

200℃

217

0

70s~120s

40s~60s

Between 1~3℃/S

Preheat Heating Cooling

℃

s

Liquids Temperature

Figure 57: Ramp-Soak-Spike reflow profile

7.3. Packaging

M50 modules are distributed in trays of 20 pieces each. This is especially suitable for the M50

according to SMT processes requirements.

The trays are stored inside a vacuum-sealed bag which is ESD protected. It should not be opened

until the devices are ready to be soldered onto the application.

Figure 58: Module tray

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Appendix A: GPRS coding schemes

Four coding schemes are used in GPRS protocol. The differences between them are shown in

Table 39.

Table 39: Description of different coding schemes

Scheme Code

rate

USF Pre-coded

USF

Radio

Block

excl.USF

and BCS

BCS Tail Coded

bits

Punctured

bits

Data

rate

Kb/s

CS-1 1/2 3 3 181 40 4 456 0 9.05

CS-2 2/3 3 6 268 16 4 588 132 13.4

CS-3 3/4 3 6 312 16 4 676 220 15.6

CS-4 1 3 12 428 16 - 456 - 21.4

Radio block structure of CS-1, CS-2 and CS-3 is shown as Figure 60:

Figure 59: Radio block structure of CS-1, CS-2 and CS-3

Radio block structure of CS-4 is shown as Figure 61:

Figure 60: Radio block structure of CS-4

Block

code

No coding

456 bits

USF

BCS

Radio Block

Rate 1/2 convolutional coding

Puncturing

456 bits

USF

BCS

Radio Block

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Appendix B: GPRS multi-slot classes

Twenty-nine classes of GPRS multi-slot modes are defined for MS in GPRS specification.

Multi-slot classes are product dependant, and determine the maximum achievable data rates in

both the uplink and downlink directions. Written as 3+1 or 2+2, the first number indicates the

amount of downlink timeslots, while the second number indicates the amount of uplink timeslots.

The active slots determine the total number of slots the GPRS device can use simultaneously for

both uplink and downlink communications. The description of different multi-slot classes is

shown in Table 40.

Table 40: GPRS multi-slot classes

Multislot class Downlink slots Uplink slots Active slots

1 1 1 2

2 2 1 3

3 2 2 3

4 3 1 4

5 2 2 4

6 3 2 4

7 3 3 4

8 4 1 5

9 3 2 5

10 4 2 5

11 4 3 5

12 4 4 5

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Room 501, Building 13, No.99 Tianzhou Road, Shanghai, China 200233

Tel: +86 21 5108 6236

Mail: info@quectel.com

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Quectel Wireless Solutions 201211M50 GSM/GPRS Module User Manual M10 Hardware Design

Quectel Wireless Solutions Company Limited GSM/GPRS Module M10 Hardware Design

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