Quectel Wireless Solutions 201605M35 User Manual

M35 User Manual

GSM/GPRS Module Series

Rev. M35_User_Manual_V3.1 Date: 2014-11-26

www.quectel.com

GSM/GPRS Module Series

M35 User Manual

Our aim is to provide customers with timely and comprehensive service. For any assistance, please contact our company headquarters:

Quectel Wireless Solutions Co., Ltd.

Office 501, Building 13, No.99, Tianzhou Road, Shanghai, China, 200233 Tel: +86 21 5108 6236 Mail: info@quectel.com

Or our local office, for more information, please visit:

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For technical support, to report documentation errors, please visit:

http://www.quectel.com/support/techsupport.aspx

GENERAL NOTES

QUECTEL OFFERS THIS INFORMATION AS A SERVICE TO ITS CUSTOMERS. THE INFORMATION

PROVIDED IS BASED UPON CUSTOMERS’ REQUIREMENTS. QUECTEL MAKES EVERY EFFORT

TO ENSURE THE QUALITY OF THE INFORMATION IT MAKES AVAILABLE. QUECTEL DOES NOT MAKE ANY WARRANTY AS TO THE INFORMATION CONTAINED HEREIN, AND DOES NOT ACCEPT ANY LIABILITY FOR ANY INJURY, LOSS OR DAMAGE OF ANY KIND INCURRED BY USE OF OR RELIANCE UPON THE INFORMATION. ALL INFORMATION SUPPLIED HEREIN IS SUBJECT TO CHANGE WITHOUT PRIOR NOTICE.

COPYRIGHT

THIS INFORMATION CONTAINED HERE IS PROPRIETARY TECHNICAL INFORMATION OF QUECTEL CO., LTD. TRANSMITTABLE, REPRODUCTION, DISSEMINATION AND EDITING OF THIS DOCUMENT AS WELL AS UTILIZATION OF THIS CONTENTS ARE FORBIDDEN WITHOUT PERMISSION. OFFENDERS WILL BE HELD LIABLE FOR PAYMENT OF DAMAGES. ALL RIGHTS ARE RESERVED IN THE EVENT OF A PATENT GRANT OR REGISTRATION OF A UTILITY MODEL OR DESIGN.

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Revision

Date

Author

Description

1.0

2011-12-29

Luka WU

Initial

1.1

2012-05-18

Luka WU

1. Added current consumption in GPRS communication mode.

2. Modified AT command AT+QAUDCH in Chapter

3.10.

3. Modified the Footprint of recommendation.

4. Updated module package type.

1.2

2012-09-19

Luka WU

1. Updated module functional diagram.

2. Updated Voltage ripple during transmitting.

3. Modified level match reference circuits for 5V peripheral system.

4. Updated SIM card reference circuit.

5. Added module current consumption.

1.3

2013-09-03

Winter CHEN

1. Updated information on module’s packaging.

2. Used the new technical document template.

1.4

2013-11-04

Felix YIN

Optimized the parameters of VBAT ripple in Table 24.

3.0

2014-07-25

Winter CHEN

1. Added information for SIM2 interface, DTR and DCD pin.

2. Added information for Multi UART.

3. Modified module’s current consumption.

4. Modified module’s pin definition.

5. Modified DC characteristics of module pin.

3.1

2014-11-26

Winter CHEN

1. Added information for PCM interface.

2. Updated Figure 5: Reference Circuit for Power

Supply.

3. Modified over-voltage or under-voltage

automatic shutdown in Section 3.4.2

4. Modified RTC backup in Section 3.6

M35 User Manual

About the Document

History

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GSM/GPRS Module Series

5. Modified UART application in Section 3.7.3

6. Modified SIM card interface in Section 3.10

7. Added antenna requirement in Section 4.5

M35 User Manual

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M35 User Manual

Contents

About the Document ................................................................................................................................... 2

Contents ....................................................................................................................................................... 4

Table Index ................................................................................................................................................... 7

Figure Index ................................................................................................................................................. 8

1 Introduction ........................................................................................................................................ 10

1.1. Safety Information ................................................................................................................. 11

2 Product Concept ................................................................................................................................ 12

2.1. General Description ............................................................................................................... 12

2.2. Directives and Standards ...................................................................................................... 12

2.2.1. FCC Radiation Exposure Statement .............................................................................. 12

2.3. Key Features ......................................................................................................................... 13

2.4. Functional Diagram ............................................................................................................... 15

2.5. Evaluation Board ................................................................................................................... 16

3 Application Interface ......................................................................................................................... 17

3.1. Pin of Module ......................................................................................................................... 18

3.1.1. Pin Assignment .............................................................................................................. 18

3.1.2. Pin Description ............................................................................................................... 19

3.2. Operating Modes ................................................................................................................... 23

3.3. Power Supply ........................................................................................................................ 25

3.3.1. Power Features of Module ............................................................................................. 25

3.3.2. Decrease Supply Voltage Drop ...................................................................................... 25

3.3.3. Reference Design for Power Supply .............................................................................. 26

3.3.4. Monitor Power Supply .................................................................................................... 27

3.4. Power On and Down Scenarios ............................................................................................ 27

3.4.1. Power On ....................................................................................................................... 27

3.4.2. Power Down ................................................................................................................... 29

3.4.2.1. Power Down Module Using the PWRKEY Pin .................................................. 29

3.4.2.2. Power Down Module Using AT Command ........................................................ 30

3.4.2.3. Over-voltage or Under-voltage Automatic Shutdown ........................................ 30

3.4.2.4. Emergency Shutdown Using EMERG_OFF Pin ............................................... 31

3.4.3. Restart ............................................................................................................................ 32

3.5. Power Saving ........................................................................................................................ 33

3.5.1. Minimum Functionality Mode ......................................................................................... 33

3.5.2. SLEEP Mode .................................................................................................................. 34

3.5.3. Wake Up Module from SLEEP Mode ............................................................................. 34

3.5.4. Summary of State Transition .......................................................................................... 35

3.6. RTC Backup .......................................................................................................................... 35

3.7. Serial Interfaces ..................................................................................................................... 37

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3.7.1. UART Port ...................................................................................................................... 39

3.7.1.1. The Features of UART Port ............................................................................... 39

3.7.1.2. The Connection of UART .................................................................................. 40

3.7.1.3. Firmware Upgrade ............................................................................................. 42

3.7.2. Debug Port ..................................................................................................................... 42

3.7.3. UART Application ........................................................................................................... 43

3.8. Audio Interfaces ..................................................................................................................... 44

3.8.1. Decrease TDD Noise and Other Noise .......................................................................... 46

3.8.2. Microphone Interfaces Design ....................................................................................... 46

3.8.3. Receiver Interface Design .............................................................................................. 47

3.8.4. Earphone Interface Design ............................................................................................ 47

3.8.5. Loud Speaker Interface Design ..................................................................................... 48

3.8.6. Audio Characteristics ..................................................................................................... 48

3.9. PCM Interface ........................................................................................................................ 49

3.9.1. Configuration .................................................................................................................. 50

3.9.2. Timing ............................................................................................................................. 50

3.9.3. Reference Design .......................................................................................................... 52

3.9.4. AT Command ................................................................................................................. 52

3.10. SIM Card Interfaces .............................................................................................................. 53

3.10.1. SIM Card Application ...................................................................................................... 53

3.11. Behaviors of The RI ............................................................................................................... 57

3.12. Network Status Indication ...................................................................................................... 58

3.13. Operating Status Indication ................................................................................................... 59

4 Antenna Interface ............................................................................................................................... 61

4.1. RF Reference Design ............................................................................................................ 61

4.2. RF Output Power ................................................................................................................... 62

4.3. RF Receiving Sensitivity ........................................................................................................ 62

4.4. Operating Frequencies .......................................................................................................... 63

4.5. Antenna Requirement ........................................................................................................... 63

4.6. RF Cable Soldering ............................................................................................................... 64

5 Electrical, Reliability and Radio Characteristics ............................................................................ 65

5.1. Absolute Maximum Ratings................................................................................................... 65

5.2. Operating Temperature ......................................................................................................... 65

5.3. Power Supply Ratings ........................................................................................................... 66

5.4. Current Consumption ............................................................................................................ 67

5.5. Electro-static Discharge ........................................................................................................ 68

6 Mechanical Dimensions .................................................................................................................... 70

6.1. Mechanical Dimensions of Module ....................................................................................... 70

6.2. Recommended Footprint ....................................................................................................... 72

6.3. Top View of the Module ......................................................................................................... 73

6.4. Bottom View of the Module ................................................................................................... 73

7 Storage and Manufacturing .............................................................................................................. 74

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7.1. Storage .................................................................................................................................. 74

7.2. Soldering ............................................................................................................................... 74

7.3. Packaging .............................................................................................................................. 75

7.3.1. Tape and Reel Packaging .............................................................................................. 75

8 Appendix A Reference ....................................................................................................................... 78

9 Appendix B GPRS Coding Scheme ................................................................................................. 83

10 Appendix C GPRS Multi-slot Class .................................................................................................. 85

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Table Index

TABLE 1: MODULE KEY FEATURES ............................................................................................................... 13

TABLE 2: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE ........................ 15

TABLE 3: PIN DESCRIPTION ........................................................................................................................... 19

TABLE 4: MULTIPLEXED FUNCTIONS ............................................................................................................ 23

TABLE 5: OVERVIEW OF OPERATING MODES ............................................................................................. 23

TABLE 6: SUMMARY OF STATE TRANSITION ............................................................................................... 35

TABLE 7: LOGIC LEVELS OF THE UART INTERFACES ................................................................................ 38

TABLE 8: PIN DEFINITION OF THE UART INTERFACES .............................................................................. 38

TABLE 9: PIN DEFINITION OF AUDIO INTERFACE ....................................................................................... 44

TABLE 10: AOUT2 OUTPUT CHARACTERISTICS .......................................................................................... 45

TABLE 11: TYPICAL ELECTRET MICROPHONE CHARACTERISTICS ......................................................... 48

TABLE 12: TYPICAL SPEAKER CHARACTERISTICS .................................................................................... 48

TABLE 13: PIN DEFINITION OF PCM INTERFACE ......................................................................................... 49

TABLE 14: CONFIGURATION ........................................................................................................................... 50

TABLE 15: QPCMON COMMAND DESCRIPTION .......................................................................................... 53

TABLE 16: QPCMVOL COMMAND DESCRIPTION ......................................................................................... 53

TABLE 17: PIN DEFINITION OF THE SIM INTERFACES ................................................................................ 54

TABLE 18: BEHAVIORS OF THE RI ................................................................................................................. 57

TABLE 19: WORKING STATE OF THE NETLIGHT .......................................................................................... 58

TABLE 20: PIN DEFINITION OF THE STATUS ................................................................................................ 59

TABLE 21: PIN DEFINITION OF THE RF_ANT ................................................................................................ 61

TABLE 22: THE MODULE CONDUCTED RF OUTPUT POWER .................................................................... 62

TABLE 23: THE MODULE CONDUCTED RF RECEIVING SENSITIVITY ....................................................... 62

TABLE 24: THE MODULE OPERATING FREQUENCIES ................................................................................ 63

TABLE 25: ANTENNA CABLE REQUIREMENTS ............................................................................................. 63

TABLE 26: ANTENNA REQUIREMENTS .......................................................................................................... 63

TABLE 27: ABSOLUTE MAXIMUM RATINGS .................................................................................................. 65

TABLE 28: OPERATING TEMPERATURE ........................................................................................................ 65

TABLE 29: THE MODULE POWER SUPPLY RATINGS .................................................................................. 66

TABLE 30: THE MODULE CURRENT CONSUMPTION .................................................................................. 67

TABLE 31: THE ESD ENDURANCE (TEMPERATURE: 25ºC, HUMIDITY: 45%) ............................................ 69

TABLE 32: REEL PACKING .............................................................................................................................. 77

TABLE 33: RELATED DOCUMENTS ................................................................................................................ 78

TABLE 34: TERMS AND ABBREVIATIONS ...................................................................................................... 79

TABLE 35: DESCRIPTION OF DIFFERENT CODING SCHEMES .................................................................. 83

TABLE 36: GPRS MULTI-SLOT CLASSES ...................................................................................................... 85

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M35 User Manual

Figure Index

FIGURE 1: MODULE FUNCTIONAL DIAGRAM ............................................................................................... 16

FIGURE 2: PIN ASSIGNMENT ......................................................................................................................... 18

FIGURE 3: VOLTAGE RIPPLE DURING TRANSMITTING .............................................................................. 25

FIGURE 4: REFERENCE CIRCUIT FOR THE VBAT INPUT ........................................................................... 26

FIGURE 5: REFERENCE CIRCUIT FOR POWER SUPPLY ............................................................................ 26

FIGURE 6: TURN ON THE MODULE WITH AN OPEN-COLLECTOR DRIVER .............................................. 27

FIGURE 7: TURN ON THE MODULE WITH A BUTTON .................................................................................. 28

FIGURE 8: TURN-ON TIMING .......................................................................................................................... 28

FIGURE 9: TURN-OFF TIMING ........................................................................................................................ 29

FIGURE 10: AN OPEN-COLLECTOR DRIVER FOR EMERG_OFF ................................................................ 31

FIGURE 11: REFERENCE CIRCUIT FOR EMERG_OFF BY USING BUTTON .............................................. 32

FIGURE 12: TIMING OF RESTARTING SYSTEM ............................................................................................ 32

FIGURE 13: TIMING OF RESTARTING SYSTEM AFTER EMERGENCY SHUTDOWN ................................ 33

FIGURE 14: VRTC IS SUPPLIED BY A NON-CHARGEABLE BATTERY ........................................................ 36

FIGURE 15: VRTC IS SUPPLIED BY A RECHARGEABLE BATTERY ............................................................ 36

FIGURE 16: VRTC IS SUPPLIED BY A CAPACITOR ...................................................................................... 36

FIGURE 17: REFERENCE DESIGN FOR FULL-FUNCTION UART ................................................................ 40

FIGURE 18: REFERENCE DESIGN FOR UART PORT ................................................................................... 41

FIGURE 19: REFERENCE DESIGN FOR UART PORT WITH HARDWARE FLOW CONTROL .................... 41

FIGURE 20: REFERENCE DESIGN FOR FIRMWARE UPGRADE ................................................................. 42

FIGURE 21: REFERENCE DESIGN FOR DEBUG PORT ............................................................................... 43

FIGURE 22: LEVEL MATCH DESIGN FOR 3.3V SYSTEM .............................................................................. 43

FIGURE 23: SKETCH MAP FOR RS-232 INTERFACE MATCH ...................................................................... 44

FIGURE 24: REFERENCE DESIGN FOR AIN1&AIN2 ..................................................................................... 46

FIGURE 25: REFERENCE INTERFACE DESIGN OF AOUT1 ......................................................................... 47

FIGURE 26: EARPHONE INTERFACE DESIGN .............................................................................................. 47

FIGURE 27: LOUD SPEAKER INTERFACE DESIGN ...................................................................................... 48

FIGURE 28: LONG SYNCHRONIZATION & SIGN EXTENSION DIAGRAM ................................................... 51

FIGURE 29: LONG SYNCHRONIZATION & ZERO PADDING DIAGRAM....................................................... 51

FIGURE 30: SHORT SYNCHRONIZATION & SIGN EXTENSION DIAGRAM ................................................. 51

FIGURE 31: SHORT SYNCHRONIZATION & ZERO PADDING DIAGRAM .................................................... 52

FIGURE 32: REFERENCE DESIGN FOR PCM ............................................................................................... 52

FIGURE 33: REFERENCE CIRCUIT FOR SIM1 INTERFACE WITH 8-PIN SIM CARD HOLDER ................. 55

FIGURE 34: REFERENCE CIRCUIT FOR SIM1 INTERFACE WITH THE 6-PIN SIM CARD HOLDER ......... 55

FIGURE 35: REFERENCE CIRCUIT FOR SIM2 INTERFACE WITH THE 6-PIN SIM CARD HOLDER ......... 56

FIGURE 36: RI BEHAVIOR OF VOICE CALLING AS A RECEIVER ................................................................ 57

FIGURE 37: RI BEHAVIOR AS A CALLER ....................................................................................................... 58

FIGURE 38: RI BEHAVIOR OF URC OR SMS RECEIVED ............................................................................. 58

FIGURE 39: REFERENCE DESIGN FOR NETLIGHT ..................................................................................... 59

FIGURE 40: REFERENCE DESIGN FOR STATUS .......................................................................................... 60

FIGURE 41: REFERENCE DESIGN FOR RF .................................................................................................. 61

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FIGURE 42: RF SOLDERING SAMPLE ........................................................................................................... 64

FIGURE 43: M35 MODULE TOP AND SIDE DIMENSIONS (UNIT: MM) ......................................................... 70

FIGURE 44: M35 MODULE BOTTOM DIMENSIONS (UNIT: MM) ................................................................... 71

FIGURE 45: RECOMMENDED FOOTPRINT (UNIT: MM) ................................................................................ 72

FIGURE 46: TOP VIEW OF THE MODULE ...................................................................................................... 73

FIGURE 47: BOTTOM VIEW OF THE MODULE .............................................................................................. 73

FIGURE 48: RAMP-SOAK-SPIKE REFLOW PROFILE .................................................................................... 75

FIGURE 49: TAPE AND REEL SPECIFICATION .............................................................................................. 76

FIGURE 50: DIMENSIONS OF REEL ............................................................................................................... 77

FIGURE 51: RADIO BLOCK STRUCTURE OF CS-1, CS-2 AND CS-3 ........................................................... 83

FIGURE 52: RADIO BLOCK STRUCTURE OF CS-4 ....................................................................................... 84

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M35 User Manual

1 Introduction

This document defines the M35 module and describes its hardware interface which are connected with your application and the air interface.

This document can help you quickly understand module interface specifications, electrical and mechanical details. Associated with application notes and user guide, you can use M35 module to design and set up mobile applications easily.

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Full attention must be given to driving at all times in order to reduce the risk of an accident. Using a mobie while driving (even with a handsfree kit) cause distraction and can lead to an accident. You must comply with laws and regulations restrcting the use of wireless devices while driving.

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. Consult the airline staff about the use of wireless devices on boarding the aircraft. If your device offers a Flight Mode which must be enabled prior to boarding an aircraft.

Switch off your wireless device when in hospitals or clinics or other health care facilities. These requests are desinged to prevent possible interference with sentitive medical equipment.

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.

Your cellular terminal or mobile contains a transmitter and receiver. When it is ON , it receives and transmits radio frequency energy. RF interference can occur if it is used close to TV set, radio, computer or other electric equipment.

In locations with potencially explosive atmospheres, obey all posted signs to turn off wireless devices such as your phone or other cellular terminals. Areas with potencially exposive atmospheres including fuelling areas, below decks on boats, fuel or chemical transfer or storage facilities, areas where the air contains chemicals or particles such as grain, dust or metal powders.

M35 User Manual

1.1. Safety Information

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 M35 module. 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 your failure to comply with these precautions.

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2 Product Concept

2.1. General Description

M35 is a Quad-band GSM/GPRS engine that works at frequencies of GSM850MHz, EGSM900, DCS1800 and PCS1900MHz. The M35 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 B & C.

With a tiny profile of 19.9mm × 23.6mm × 2.65mm, 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.

M35 is an SMD type module with LCC package, which can be easily embedded into applications. It provides abundant hardware interfaces like Audio and UART Interface.

Designed with power saving technique, the current consumption of M35 is as low as 1.3 mA in SLEEP mode when DRX is 5.

M35 is integrated with Internet service protocols, such as TCP/UDP, FTP and PPP. Extended AT commands have been developed for you to use these Internet service protocols easily.

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

2.2. Directives and Standards

The M35 module is designed to comply with the FCC statements. FCC ID: XMR201512M35 The Host system using M35, should have label indicated FCC ID: XMR201512M35.

2.2.1. 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

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Part Number

Frequency Range (MHz)

Peak Gain

(XZ-V)

Average Gain

(XZ-V)

VSWR

Impedance

3R007A

GSM850: TX 824-849MHz RX 869-894MHz PCS1900： TX 1850-1910MHz RX 1930-1990MHz

1 dBi typ.

3 max

50Ω

Feature

Implementation

M35 User Manual

module usage. This module should NOT be installed and operating simultaneously with other radio.

The manual of the host system, which uses M35 must include RF exposure warning statement to advice user should keep minimum 20cm from the radio antenna of M35 module depending on the Mobile status.

Note: If a portable device (such as PDA) uses M35 module, the device needs to do permissive change and SAR testing.

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

Antenna gain including cable loss must not exceed 4.95 dBi of GSM 850 and 2.5 dBi of PCS 1900 for th e purpose of satisfying the requirements of 2.1043 and 2.1091. The antenna(s) used for this transmitter must be installed to provide a separation distance of at least 20cm from all persons and must not be co-located or operated in conjunction with any antenna or transmitter not described under this FCC ID. The final product operating with this transmitter must include operating instructions and antenna installation instructions, for end-users and installers to satisfy RF exposure compliance requirements. Compliance of this device in all final product configurations is the responsibility of the Grantee. Installation of this device into specific final products may require the submission of a Class II permissive change application containing data pertinent to RF Exposure, spurious emissions, ERP/EIRP, and host/module authentication, or new application if appropriate. Installation of this device into specific final products may require the submission of a Class II permissive change application containing data pertinent to RF Exposure, spurious emissions, ERP/EIRP, and host/module authentication, or new application if appropriate.

2.3. Key Features

The following table describes the detailed features of M35 module.

Table 1: Module Key Features

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Power Supply

Single supply voltage: 3.3V ~ 4.6V Typical supply voltage: 4V

Power Saving

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

1.2 mA @DRX=9

Frequency Bands

 Quad-band: GSM850, EGSM900, DCS1800, PCS1900  The module can search these frequency bands automatically  The frequency bands can be set by AT command  Compliant to GSM Phase 2/2+

GSM Class

Small MS

Transmitting Power

 Class 4 (2W) at GSM850 and EGSM900  Class 1 (1W) at DCS1800 and PCS1900

GPRS Connectivity

 GPRS multi-slot class 10 (default)  GPRS multi-slot class 1~10 (configurable)  GPRS mobile station class B

DATA GPRS

 GPRS data downlink transfer: max. 85.6kbps  GPRS data uplink transfer: max. 85.6kbps  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/MMS/SMTP/PING

 Support Packet Broadcast Control Channel (PBCCH)  Support Unstructured Supplementary Service Data (USSD)

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

SMS

 Text and PDU mode  SMS storage: SIM card

SIM Interfaces

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  Noise Reduction  Embedded one amplifier of class AB with maximum driving power up

to 870mW

UART Interfaces

UART Port:

 Seven lines on UART port interface  Used for AT command, GPRS data  Multiplexing function

M35 User Manual

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1)

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

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

 Support autobauding from 4800bps to 115200bps Debug Port:

 Two lines on debug port interface DBG_TXD and DBG_RXD  Debug Port can used for firmware debugging

Phonebook Management

Support phonebook types: SM, ME, FD, ON, MT

SIM Application Toolkit

Support SAT class 3, GSM 11.14 Release 99

Real Time Clock

Supported

Physical Characteristics

Size: 19.9±0.15 × 23.6±0.15 × 2.65±0.2mm Weight: Approx. 2.5g

Firmware Upgrade

Firmware upgrade via UART Port

Antenna Interface

Connected to antenna pad with 50 Ohm impedance control

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

NOTE

M35 User Manual

Table 2: Coding Schemes and Maximum Net Data Rates over Air Interface

2.4. Functional Diagram

The following figure shows a block diagram of M35 and illustrates the major functional parts.

 Radio frequency part  Power management  The Peripheral interface

—Power supply

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BB&RF

RF PAM

26MHzRF Transceiver

RTC

GPIO&

PWM

Serial

Interface

SIM

Interface

RF_ANT

VBAT

PWRKEY

EMERG_OFF

VRTC

Status& Netlight

UART

SIM

Interfaces

Reset

ESD

PMU

MEMORY

Audio

PCM

Interface

PCM

M35 User Manual

—Turn-on/off interface —UART interfaces —RTC interface —Audio interfaces —PCM interface —SIM interfaces —RF interface

2.5. Evaluation Board

In order to help you to develop applications with M35, 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 [4].

Figure 1: Module Functional Diagram

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M35 User Manual

3 Application Interface

The module adopts LCC package and has 42 pins. The following chapters provide detailed descriptions about these pins below:

 Power supply  Power on/down  RTC  Serial interfaces  Audio interfaces  PCM interface  SIM interfaces  RI  NETLIGHT  STATUS

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VBAT

RF

Other

GND

UART

Audio

Power

SIM

SIM_GND

31

SIM1_CLK

30

SIM1_DATA

29

SIM1_RST

28

SIM1_VDD

27

PCM_OUT

41

PCM_IN

42

SIM2_VDD

18

SIM2_CLK

17

SIM2_DATA

16

19

VDD_EXT

PWRKEY

10

EMERG_OFF

11

STATUS/ PCM_SYNC

12

NETLIGHT

13

Top view

37

GND

39

RF_ANT

34

VBAT

1

AGND

32

VRTC

38

GND

40

GND

36

GND35GND

33

VBAT

25

DCD/SIM2_RST

24

RTS

23

CTS

22

TXD

21

RXD

26

RI/PCM_CLK

2

MIC2P

3

MIC2N

4

MIC1P

5

MIC1N

6

SPK1N

7

SPK1P

8

LOUDSPKN

9

LOUDSPKP

14

DBG_RXD

15

DBG_TXD

20

DTR/SIM1_PRESENCE

PCM

M35 User Manual

3.1. Pin of Module

3.1.1. Pin Assignment

Figure 2: Pin Assignment

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GSM/GPRS Module Series

Power Supply

PIN NAME

PIN NO.

I/O

DESCRIPTION

DC CHARACTERISTICS

COMMENT

VBAT

33, 34

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 typically rises to

1.6A.

VRTC

32

I/O

Power supply for RTC when VBAT is not supplied for the system. Charging for backup battery or golden capacitor when the VBAT is applied.

VImax=3.3V VImin=1.5V VInorm=2.8V VOmax=3V VOmin=2V VOnorm=2.8V Iout(max)=2mA Iin≈10uA

If unused, keep this pin open.

VDD_ EXT

19

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. Recommend to

add a 2.2~4.7uF bypass capacitor, when using this pin for power supply.

GND

35,36,3 7,38, 40

Ground

Turn on/off

PIN NAME

PIN NO.

I/O

DESCRIPTION

DC CHARACTERISTICS

COMMENT

PWRKEY

10

I

Power on/off key. PWRKEY should be pulled down for a moment to turn on or turn off the system.

VILmax=

0.1×VBAT

VIHmin=

0.6×VBAT

VImax=3.1V

Emergency Shutdown

M35 User Manual

3.1.2. Pin Description

Table 3: Pin Description

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GSM/GPRS Module Series

PIN NAME

PIN NO.

I/O

DESCRIPTION

DC CHARACTERISTICS

COMMENT

EMERG_ OFF

11

I

Emergency off. Pulled down for at least 40ms, which will turn off the module in case of emergency. Use it only when shutdown via PWRKEY or AT command cannot be achieved.

VILmax=0.45V VIHmin=1.35V Vopenmax=1.8V

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

STATUS

12

O

Indicate module’s

operating status. Output high level when module turns on, while output low level when module turns off.

VOHmin=

0.85×VDD_EXT

VOLmax=

0.15×VDD_EXT

If unused, keep these pins open.

Audio Interfaces

PIN NAME

PIN NO.

I/O

DESCRIPTION

DC CHARACTERISTICS

COMMENT

MIC1P MIC1N

4,5

I

Channel 1 positive and negative voice input

Refer to Section 3.8

If unused, keep these pins open.

MIC2P MIC2N

2,3

I

Channel 2 positive and negative voice input

SPK1P SPK1N

7,6

O

Channel 1 positive and negative voice output

1. If unused, keep

these pins open.

2. Support both

voice and ringtone output.

AGND

1

Analog ground. Separate ground connection for external audio circuits.

If unused, keep this pin open.

LOUD SPKN LOUD SPKP

8,9

O

Channel 3 positive and negative voice output

1. If unused, keep

these pins open.

2. Integrate a

Class- AB amplifier internally.

3. Support both

voice and ringtone output.

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GSM/GPRS Module Series

Network Status Indicator

PIN NAME

PIN NO.

I/O

DESCRIPTION

DC CHARACTERISTICS

COMMENT

NETLIGHT

13

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

20 I Data terminal ready

VILmin=0V VILmax=

0.25×VDD_EXT

VIHmin=

0.75×VDD_EXT

VIHmax=

VDD_EXT+0.2

VOHmin=

0.85×VDD_EXT

VOLmax=

0.15×VDD_EXT

If only use TXD, RXD and GND to communicate, recommended connecting RTS to GND via 0R resistor and keeping other pins open.

RXD

21 I Receive data

TXD

22 O Transmit data

RTS

24 I Request to send

CTS

23 O Clear to send

RI

26 O Ring indication

DCD

25 O Data carrier detection

Debug Port

PIN NAME

PIN NO.

I/O

DESCRIPTION

DC CHARACTERISTICS

COMMENT

DBG_ TXD

15 O Transmit data

Same as above

If unused, keep these pins open.

DBG_ RXD

14 I Receive data

SIM Interfaces

PIN NAME

PIN NO

I/O

DESCRIPTION

DC CHARACTERISTICS

COMMENT

SIM1_ VDD

27

O

Power supply for SIM1 card

The voltage can be selected by software automatically. Either

1.8V or 3V.

All signals of SIM interfaces should be protected against ESD with a TVS diode array. Maximum trace length is 200mm from the module

SIM1_ CLK

30 O SIM1 clock

VOLmax=

0.15×SIM1_VDD

VOHmin=

0.85×SIM1_VDD

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GSM/GPRS Module Series

SIM1_ DATA

29

I/O

SIM1 data

VOLmax=

0.15×SIM1_VDD

VOHmin=

0.85×SIM1_VDD

pad to SIM card holder.

SIM1_ RST

28 O SIM1 reset

VOLmax=

0.15×SIM1_VDD

VOHmin=

0.85×SIM1_VDD

SIM1_ PRESENCE

20 I SIM1 card detection.

VILmin=0V VILmax=

0.25×VDD_EXT

VIHmin=

0.75×VDD_EXT

VIHmax= VDD_EXT+0.2

SIM_ GND

31 SIM ground

SIM2_ VDD

18

O

Power supply for SIM2 card

The voltage can be selected by software automatically. Either

1.8V or 3V.

SIM2_ CLK

17 O SIM2 clock

VOLmax=

0.15×SIM2_VDD

VOHmin=

0.85×SIM2_VDD

SIM2_ DATA

16

I/O

SIM2 data

VOLmax=

0.15×SIM2_VDD

VOHmin=

0.85×SIM2_VDD

SIM2_ RST

25 O SIM2 reset

VOLmax=

0.15×SIM2_VDD

VOHmin=

0.85×SIM2_VDD

RF Interface

PIN NAME

PIN NO.

I/O

DESCRIPTION

DC CHARACTERISTICS

COMMENT

RF_ANT

39

I/O

RF antenna pad

Impedance of 50Ω

PCM Interface

PIN NAME

PIN NO.

I/O

DESCRIPTION

DC CHARACTERISTICS

COMMENT

M35 User Manual

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GSM/GPRS Module Series

1)

The alternate function can be configured through AT command. For details, please refer to the section

3.9 and section 3.10.

PCM_ SYNC

12 O PCM sync signal

VILmin=-0.3V VILmax=

0.25×VDD_EXT

VIHmin=

0.75×VDD_EXT

VIHmax=

VDD_EXT+0.2

VOHmin=

0.85×VDD_EXT

VOLmax=

0.15×VDD_EXT

The default function is STATUS after startup.

PCM_ CLK

26 O PCM clock signal

The default function is RI after startup.

PCM_ OUT

41 O PCM serial data output

If unused, keep these pins open.

PCM_IN

42 I PCM serial data input

PIN NAME

PIN NO.

Function After Reset

Alternate Function1)

STATUS/PCM_SYNC

12

STATUS

PCM_SYNC

DTR/SIM1_PRESENCE

20

DTR

SIM1_PRESENCE

DCD/SIM2_RST

25

DCD

SIM2_RST

RI/PCM_CLK

26

RI

PCM_CLK

Mode

Function

Normal Operation

GSM/GPRS Sleep

After enabling sleep mode by ―AT+QSCLK=1‖, 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 be reduced to the minimal level. During

NOTE

M35 User Manual

Table 4: Multiplexed Functions

3.2. Operating Modes

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

Table 5: Overview of Operating Modes

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GSM/GPRS Module Series

1)

Use the EMERG_OFF pin only when failing to turn off the module by the command ―AT+QPOWD=1‖

and the PWRKEY pin. For more details, please refer to the Section 3.4.2.4.

Sleep Mode, the module can still receive paging message and SMS from the system normally.

GSM IDLE

Software 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.

NOTE

M35 User Manual

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GSM/GPRS Module Series

Vdrop

4.615ms

577us

IBAT

VBAT

Burst:1.6A

M35 User Manual

3.3. Power Supply

3.3.1. Power Features of Module

The power supply is one of the key issues in designing GSM terminals. Because of the 577us radio burst 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 M35 module, the max current consumption could reach to 1.6A during a transmit burst. It will cause a large voltage drop 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.

Figure 3: Voltage Ripple during Transmitting

3.3.2. Decrease Supply Voltage Drop

The power supply range 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 VBAT route should be wide enough to ensure that there is not too much voltage drop 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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GSM/GPRS Module Series

VBAT

C2C1

+

C3 C4

GND

100uF 100nF 10pF

0603

33pF

0603

DC_IN

C1

C2

MIC29302WU U1

IN OUT

EN

GND

ADJ

2 4

1

3

5

VBAT

100nF

C3

470uFC4100nF

R2

D1

124K

56K

R3

470uF

5.1V

R4

470R

MCU_POWER_ON/OFF

47K

4.7K

R5

R6

R1 51K

M35 User Manual

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 recommended to be used as a power supply.

Figure 5 shows a reference design for +5V input power source. The designed output for the power supply is 4.0V 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 of which reverse zener voltage is 5.1V and dissipation power is more than 1 Watt.

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Figure 5: Reference Circuit for Power Supply

GSM/GPRS Module Series

It is suggested to control the module’s main power supply (VBAT) via LDO enable pin to restart the module when the module has become abnormal. Power switch circuit like P-channel MOSFET switch circuit can also be used to control VBAT.

Turn on pulse

PWRKEY

4.7K

47K

1. M35 module is set to autobauding mode (AT+IPR=0) by default. In the autobauding mode, URC ―RDY‖ is not reported to the host controller after module is powered on. When the module is powered on after a delay of 4 or 5 seconds, it can receive AT command. Host controller should first send an ―AT‖ or ―at‖ string in order that the module can detect baud rate of host controller, it should continue to send the next ‖AT‖ string until receiving ―OK‖ string from the module. Then enter ―AT+IPR=x;&W‖ to set a fixed baud rate for the module and save the configuration to flash memory of the module. After

NOTE

M35 User Manual

3.3.4. Monitor Power Supply

The command ―AT+CBC‖ can be used to monitor the supply voltage of the module. The unit of the displayed voltage is mV.

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

3.4. Power On and Down Scenarios

3.4.1. Power On

The module can be turned on by driving the pin PWRKEY to a low level voltage. An open collector driver circuit is suggested to control the PWRKEY. A simple reference circuit is illustrated as below.

Figure 6: Turn On the Module with an Open-collector Driver

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GSM/GPRS Module Series

these configurations, the URC ―RDY‖ would be received from the UART Port of the module every time when the module is powered on. For more details, refer to the section ―AT+IPR‖ in document [1].

2. AT command response indicates module is turned on successfully, or else the module fails to be turned on.

PWRKEY

S1

Close to

S1

TVS

VDD_EXT (OUTPUT)

VIL<0.1*VBAT

V

IH

> 0.6*VBAT

VBAT

PWRKEY

(INPUT)

EMERG_OFF

(INPUT)

54ms

STATUS

(OUTPUT)

800ms

>1s

OFF

BOOTING

MODULE

STATUS

RUNNING

T

1

M35 User Manual

The other way to control the PWRKEY is through a button directly. A TVS component is indispensable to be placed nearby the button for ESD protection. For the best performance, the TVS component must be placed nearby the button. When pressing the key, electrostatic strike may generate from finger. A reference circuit is shown in the following figure.

Figure 7: Turn On the Module with a Button

The turn-on timing is illustrated as the following figure.

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Figure 8: Turn-on Timing

GSM/GPRS Module Series

1. Make sure that VBAT is stable before pulling down PWRKEY pin. The time of T1 is recommended as 100ms.

2. EMERG_OFF should be floated when it is unused.

3. For more details about the application of STATUS pin, please refer to the Chapter 3.13.

VBAT

PWRKEY

(INPUT)

STATUS

(OUTPUT)

EMERG_OFF

(INPUT)

Logout net about 2s to 12s

0.7s<Pulldown<1s

NOTE

M35 User Manual

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=1‖.  Over-voltage or under-voltage automatic shutdown: Take effect when over-voltage or 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

It is a safe way to 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.

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.

Figure 9: Turn-off Timing

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GSM/GPRS Module Series

1. 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.

2. As logout network time is related to the local mobile network, it is recommended to delay about 12 seconds before disconnecting the power supply or restarting the module.

3. For more details about the application of STATUS pin, please refer to the Chapter 3.13.

NOTE

M35 User Manual

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. Then the module enters the power down mode, only the RTC is still active.

3.4.2.2. Power Down Module Using AT Command

It is also a safe way to 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.

Before the completion of the power down procedure, the module sends the result code as 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.

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

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GSM/GPRS Module Series

1. These result codes do not appear when autobauding is active and DTE and DCE are not correctly synchronized after start-up. The module is recommended to set to a fixed baud rate.

2. Over-voltage warning and shutdown function is disabled by default.

Emergency

shutdown pulse

EMERG_OFF

4.7K

47K

NOTE

M35 User Manual

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 shut down 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

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.

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 40ms 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.

Figure 10: An Open-collector Driver for EMERG_OFF

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GSM/GPRS Module Series

S2

EMERG_OFF

TVS2

Close to S2

PWRKEY

(INPUT)

STATUS

(OUTPUT)

Delay >500ms

Turn off

Restart

Pull down the PWRKEY

to turn on the module

M35 User Manual

Figure 11: Reference Circuit for EMERG_OFF by Using Button

Be cautious to use the pin EMERG_OFF. It should only be used under emergent situation. For instance, if the module is unresponsive or abnormal, the pin EMERG_OFF could be used to shut down the system. Although turning off the module by EMERG_OFF is fully tested and nothing wrong detected, this operation is still a big risk as it could cause destroying of the code or data area of the flash memory in the module. Therefore, it is recommended that PWRKEY or AT command should always be the preferential way to turn off the system.

3.4.3. Restart

The module can be restarted by driving the PWRKEY to a low level voltage for a certain time, which is similar to the way of turning on module. In order to make the internal LDOs discharge completely after turning off the module, it is recommended to delay about 500ms before restarting the module. The restart timing is illustrated as the following figure.

Figure 12: Timing of Restarting System

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GSM/GPRS Module Series

EMERG_OFF

(INPUT)

STATUS

(OUTPUT)

Delay >500ms

Pulldown >40ms

PWRKEY

(INPUT)

For more details about the application of STATUS pin, please refer to the Chapter 3.13.

NOTE

M35 User Manual

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

3.5. Power Saving

Based on system requirements, 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.

3.5.1. Minimum Functionality Mode

Minimum functionality mode reduces the functionality of the module to a minimum level. The consumption of the current can be minimized when the slow clocking mode is activated at the same time. The 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.

Figure 13: Timing of Restarting System after Emergency Shutdown

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GSM/GPRS Module Series

DTR pin should be held at low level during communication between the module and DTE.

NOTE

M35 User Manual

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 related with RF function or SIM card function will be not available.

If the module has been set by the command with ―AT+CFUN=4‖, the RF function will be disabled, but the UART port is still active. In this case, all AT commands related with RF function will be not available.

After the module is set by ―AT+CFUN=0‖ or ―AT+CFUN=4‖, it can return to full functionality by ―AT+CFUN=1‖.

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

3.5.2. SLEEP Mode

The SLEEP mode is disabled by default. You can enable it 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 the module is set by the command with ―AT+QSCLK=1‖, you 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 does not work.

3.5.3. 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.

 Receiving a voice or data call from network will wake up the module.  Receiving an SMS from network will wake up the module.

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GSM/GPRS Module Series

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 voice call or SMS or data call

M35 User Manual

3.5.4. Summary of State Transition

Table 6: Summary of State Transition

3.6. RTC Backup

The RTC (Real Time Clock) function is supported. The RTC is designed to work with an internal power supply.

There are three kinds of designs for RTC backup power:

 Use VBAT as the RTC power source.

When the module is turned off and the main power supply (VBAT) is remained, the real time clock is still active as the RTC core is supplied by VBAT. In this case, the VRTC pin can be kept floating.

 Use VRTC as the RTC power source.

If the main power supply (VBAT) is removed after the module is turned off, a backup supply such as a coin-cell battery (rechargeable or non-chargeable) or a super-cap can be used to supply the VRTC pin to keep the real time clock active.

 Use VBAT and VRTC as the RTC power source.

As only powering the VRTC pin to keep the RTC will lead an error about 5 minutes a day, it is recommended to power VBAT and VRTC pin at the same time when RTC function is needed. The recommended supply for RTC core circuits are shown as below.

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GSM/GPRS Module Series

Non-chargeable

Backup Battery

Module

RTC

Core

VBAT

Power Supply

LDO/DCDC

LDO

VRTC

1.5K

Rechargeable

Backup Battery

Module

RTC Core

VBAT

Power Supply

LDO/DCDC

LDO

VRTC

1.5K

Module

RTC Core

VBAT

Power Supply

LDO/DCDC

LDO

VRTC

1.5K

Large Capacitance

Capacitor

M35 User Manual

Figure 14: VRTC Is Supplied by a Non-chargeable Battery

Figure 15: VRTC Is Supplied by a Rechargeable Battery

Figure 16: VRTC Is Supplied by a Capacitor

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GSM/GPRS Module Series

If the module is only powered by VRTC , the real time will have an error about 5 minutes a day. If you want to keep an accurate real time, please use VBAT to supply the RTC core.

Hardware flow control is disabled 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].

NOTE

M35 User Manual

For the choice of a rechargeable or non-chargeable coin-cell battery, please visit http://www.sii.co.jp/en/.

3.7. Serial Interfaces

The module provides two serial ports: UART Port and Debug 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 up the module).  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).

The Debug Port:

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

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GSM/GPRS Module Series

1.

1)

DTR pin can be used as SIM1_PRESENCE pin via ―AT+QSIMDET‖ command.

2.

2)

When using the SIM2 interface, DCD pin can be used as SIM2_RST pin. For more details, please

refer to the document [6].

3.

3)

When using the PCM interface, RI pin can be used as PCM_CLK.

Parameter

Min.

Max.

Unit

VIL 0 0.25×VDD_EXT

V

VIH

0.75×VDD_EXT

VDD_EXT +0.2

V

VOL 0 0.15×VDD_EXT

V

VOH

0.85×VDD_EXT

VDD_EXT

V

Interfaces

Pin No.

Pin Name

Description

Alternate Function

Debug Port 14

DBG_RXD

Receive data

15

DBG_TXD

Transmit data

UART Port

20 1)DTR

Data terminal ready

SIM1_PRESENCE

21

RXD

Receive data

22

TXD

Transmit data

23

CTS

Clear to send

24

RTS

Request to send

25 2)DCD

Data carrier detection

SIM2_RST

26 3)RI

Ring indication

PCM_CLK

NOTE

M35 User Manual

The logic levels are described in the following table.

Table 7: Logic Levels of the UART Interfaces

Table 8: Pin Definition of the UART Interfaces

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GSM/GPRS Module Series

M35 User Manual

3.7.1. UART Port

3.7.1.1. The Features of UART Port

 Seven lines on UART interface.  Contain data lines TXD and RXD, hardware flow control lines RTS and CTS, other control lines DTR,

DCD and RI.

 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 and 115200.

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

4800, 9600, 19200, 38400, 57600 and 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:

1. Synchronization between DTE and DCE:

When DCE (the module) powers on with the autobauding enabled, it is recommended to wait 4 to 5 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.

2. Restrictions on autobauding operation:

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

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GSM/GPRS Module Series

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].

TXD RXD RTS CTS DTR DCD

RI

TXD RXD RTS CTS DTR DCD

RING

Module (DCE)

Serial portUART port

GND GND

PC (DTE)

NOTE

M35 User Manual

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

3.7.1.2. 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 UART connection is shown as below when it is applied in modulation-demodulation.

Figure 17: Reference Design for Full-Function UART

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GSM/GPRS Module Series

TXD

RXD

GND

UART port

RTS

0R

TXD

RXD

GND

Module (DCE)

Host (DTE)

Controller

RTS

CTS

RTS

CTS

GND

RXD

TXD TXD

RXD

GND

Module (DCE)

Host (DTE)

Controller

M35 User Manual

Three-line connection is shown as below.

Figure 18: Reference Design for UART Port

UART Port with hardware flow control is shown as below. This connection will enhance the reliability of the mass data communication.

Figure 19: Reference Design for UART Port with Hardware Flow Control

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GSM/GPRS Module Series

IO Connector

TXD

RXD

GND

PWRKEY

Module (DCE)

UART port

TXD

RXD

GND

PWRKEY

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.

NOTE

M35 User Manual

3.7.1.3. Firmware Upgrade

The TXD, RXD can be used to upgrade firmware. The PWRKEY pin must be pulled down before firmware upgrade. The reference circuit is shown as below:

3.7.2. Debug Port

As to Debug Port, there are two working modes, Standard Mode and Advanced Mode, which can be switched through using AT command‖ AT+QEAUART‖. For more details, please refer to the document [7].

In Standard Mode, it can be used to execute software debug and it can also connect to a peripheral device. Furthermore, its default baud rate is 115200bps.

In Advanced Mode, it can only be used to execute software debug, capture the system’s log with Cather Log tool and output the log. In this mode, its baud rate is 460800bps.

Figure 20: Reference Design for Firmware Upgrade

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GSM/GPRS Module Series

Peripheral

TXD

RXD

GND

Module

DBG_TXD

DBG_RXD

GND

Peripheral

/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

It is highly recommended to add the resistor divider circuit on the UART signal lines when the host’s level is 3V or 3.3V. For the higher voltage level system, a level shifter IC could be used between the host and the module. For more details about UART circuit design, please refer to document [8].

NOTE

M35 User Manual

The reference design for Debug Port is shown as below.

Figure 21: Reference Design for Debug Port

3.7.3. 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 10K.

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Figure 22: Level Match Design for 3.3V System

GSM/GPRS Module Series

TXD

RXD

RTS

CTS

DTR

RI

DCD

Module

GND

C1+

C1-

C2+

C2-

V+

VCC

GND

V-

3.3V

T1IN

T2IN

T3IN

T4IN

R1IN

R2IN

R3IN

R1OUT

R2OUT

R3OUT

T1OUT

T2OUT

T5OUT

T3OUT

T4OUT

T5IN

GND

/R1OUT

1

2

3

4

5

6

7

8

9

GND

To PC Serial Port

GND

1K

5.6K5.6K

1K

5.6K

RS-232 Level Shifter

Interfaces

Name

Pin NO.

Description

AIN1/AOUT1

MIC1P

4

Channel 1 Microphone positive input

MIC1N

5

Channel 1 Microphone negative input

SPK1P

7

Channel 1 Audio positive output

SPK1N

6

Channel 1 Audio negative output

AIN2/AOUT2

AGND

1

Form a pseudo-differential pair with SPK2P

M35 User Manual

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. Note that you should assure the IO voltage of level shifter which connects to module is 2.8V.

Figure 23: Sketch Map for RS-232 Interface Match

Please visit vendor web site to select the suitable RS-232 level shifter IC, such as: http://www.exar.com/ and http://www.maximintegrated.com.

3.8. Audio Interfaces

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

Table 9: Pin Definition of Audio Interface

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GSM/GPRS Module Series

MIC2P

2

Channel 2 Microphone positive input

MIC2N

3

Channel 2 Microphone negative input

LOUDSPKP

9

Channel 2 Audio positive output

LOUDSPKN

8

Channel 2 Audio negative output

Item

Condition

Min.

Type

Max.

Unit

RMS Power 8ohm load

VBAT=4.2v THD+N=1%

870

mW

8ohm load VBAT=3.3v THD+N=1%

530

mW

M35 User Manual

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. If it is used as a speaker, an amplifier should be employed.

AOUT2 is used for loudspeaker output as it embedded an amplifier of class AB whose maximum drive power is 870mW. AOUT2 is a differential channel.

AOUT2 also can be used for output of earphone, which can be used as a single-ended channel. LOUDSPKP and AGND can establish a pseudo differential mode.

All of these two audio channels support voice and ringtone output, and so on, and can be switched 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, this channel is always used for earphone.  2--AIN2/AOUT2, this channel is always used for loudspeaker.

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

Table 10: AOUT2 Output Characteristics

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GSM/GPRS Module Series

MICP

Differential

layout

Module

10pF

33pF

GND

Electret

Microphone

GND

10pF

GND

ESD

Close to Module

MICN

GND

Close to

Microphone

0603

33pF

0603

33pF 0603

33pF

0603

10pF

0603

10pF 0603

10pF

0603

M35 User Manual

3.8.1. Decrease TDD Noise and Other Noise

The 33pF capacitor is applied for filtering out 900MHz RF interference when the module is transmitting at EGSM900MHz. 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, you would have to discuss with its capacitor vendor to choose the most suitable capacitor for filtering out GSM850MHz, EGSM900MHz, 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, EGSM900 TDD noise is more severe; while in other cases, DCS1800 TDD noise is more obvious. Therefore, you 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 audio interface. 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.

3.8.2. 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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Figure 24: Reference Design for AIN1&AIN2

GSM/GPRS Module Series

SPK1P

SPK1N

Differential layout

Module

10pF

0603

Close to speaker

GND

ESD

33pF 0603

GND

10pF

0603

ESD

10pF 0603

33pF 0603

1

2

4

3

Amphenol

9001-8905-050

MIC2P

22uF

68R

33pF

GND GND

AGND

Close to Socket

AGND

33pF

10pF

GND

AGND

Module

4.7uF

LOUDSPKP

Close to Module

GND

33pF

Differential

layout

33pF

MIC2N

0R

0603

10pF

ESD

10pF

0603

M35 User Manual

3.8.3. Receiver Interface Design

Figure 25: Reference Interface Design of AOUT1

3.8.4. Earphone Interface Design

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Figure 26: Earphone Interface Design

GSM/GPRS Module Series

LOUDSPKN

0R

LOUDSPKP

8 ohm

Module

GND

Close to Speaker

10pF

33pF

10pF

33pF

GND

Differential

layout

0603

ESD

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 k Ohm

Parameter

Min.

Typ.

Max.

Unit

AOUT1 Output

Single-ended Load resistance

32 Ohm

Ref level

0 2.4

Vpp

Differential

Load resistance

32 Ohm

M35 User Manual

3.8.5. Loud Speaker Interface Design

Figure 27: Loud Speaker Interface Design

3.8.6. Audio Characteristics

Table 11: Typical Electret Microphone Characteristics

Table 12: Typical Speaker Characteristics

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GSM/GPRS Module Series

1)

When using the PCM interface, STATUS pin can be used as PCM_SYNC pin, RI pin can be used as

PCM_CLK pin.

Ref level

0 4.8

Vpp

AOUT2 Output

Differential Load resistance

8

Load Resistance

Reference level

0 2×VBAT

Vpp

Single-ended Load resistance

8

Load Resistance

Reference level

0 VBAT

Vpp

Pin NO.

Pin Name

Description

1)

Alternate Function

12

PCM_SYNC

PCM frame synchronization output

STATUS

26

PCM_CLK

PCM clock output

RI

41

PCM_OUT

PCM data output

42

PCM_IN

PCM data input

NOTE

M35 User Manual

3.9. PCM Interface

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.

M35 supports PCM interface. It is used for digital audio transmission between the module and the device. This interface is composed of PCM_CLK, PCM_SYNC, PCM_IN and PCM_OUT signal lines.

The module disables PCM interface by default. AT command ―AT+QPCMON‖ is used to configure PCM interface.

Table 13: Pin Definition of PCM Interface

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GSM/GPRS Module Series

PCM

Line Interface Format

Linear

Data Length

Linear: 13 bits

Sample 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 (line)

PCM Synchronization Format

Long/short synchronization

PCM Data Ordering

MSB first

Zero Padding

Yes

Sign Extension

Yes

M35 User Manual

3.9.1. Configuration

M35 module supports 13-bit line code PCM format. The sample rate is 8 KHz, and the clock source is 256 KHz, and the module can only act as master mode. The PCM interface supports both long and short synchronization simultaneously. Furthermore, it only supports MSB first. For detailed information, please refer to the table below.

Table 14: Configuration

3.9.2. 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 M35 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.

Under zero padding mode, you can configure the PCM input and output volume by executing

―AT+QPCMVOL‖ command. For more details, please refer to Chapter 3.9.4.

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GSM/GPRS Module Series

12 11 10

9 8 7 6 5 4 3 2 1 0

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

PCM_CLK

PCM_SYNC

PCM_OUT

PCM_IN

MSB

Sign

extension

Sign

extension

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

PCM_CLK

PCM_SYNC

PCM_OUT

PCM_IN

MSB

Zero padding

PCM_CLK

PCM_SYNC

PCM_OUT

PCM_IN

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

MSB

Sign extension

M35 User Manual

Figure 28: Long Synchronization & Sign Extension Diagram

Figure 29: Long Synchronization & Zero Padding Diagram

Figure 30: Short Synchronization & Sign Extension Diagram

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GSM/GPRS Module Series

PCM_CLK

PCM_SYNC

PCM_OUT

PCM_IN

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

MSB

Zero padding

PCM_SYNC

PCM_CLK

PCM_OUT

PCM_IN

PCM_SYNC

PCM_CLK

PCM_IN

PCM_OUT

Module

(Master)

Peripheral

(Slave)

M35 User Manual

Figure 31: Short Synchronization & Zero Padding Diagram

3.9.3. Reference Design

M35 can only work as a master, providing synchronization and clock source. The reference design is shown as below.

Figure 32: Reference Design for PCM

3.9.4. AT Command

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

―AT+QPCMON‖ can configure operating mode of PCM.

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

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GSM/GPRS Module Series

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 support

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.

M35 User Manual

Table 15: QPCMON Command Description

―AT+QPCMVOL‖ can configure the volume of input and output.

AT+QPCMVOL=vol_pcm_in, vol_pcm_out

Table 16: QPCMVOL Command Description

3.10. SIM Card Interfaces

The module contains two smart interfaces to allow module access to the two SIM cards. These two SIM interfaces share the same ground and only SIM1 interface has card inserted detection. Only one SIM card can work at a time. For more details, please refer to the document [6].

3.10.1. SIM Card Application

The SIM interfaces 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.

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GSM/GPRS Module Series

1)

If several interfaces share the same I/O pin, to avoid conflict between these alternate functions, only one

peripheral should be enabled at a time.

Pin NO.

Name

Description

1)

Alternate

Function

27

SIM1_VDD

Supply power for SIM1 card. Automatic detection of SIM1 card voltage. 3.0V±5% and 1.8V±5%. Maximum supply current is around 10mA.

30

SIM1_CLK

SIM1 card clock.

29

SIM1_DATA

SIM1 card data I/O.

28

SIM1_RST

SIM1 card reset.

20

SIM1_PRESENCE

SIM1 card detection.

DTR

31

SIM_GND

SIM card ground.

18

SIM2_VDD

Supply power for SIM2 card. Automatic detection of SIM2 card voltage. 3.0V±5% and 1.8V±5%. Maximum supply current is around 10mA.

17

SIM2_CLK

SIM2 card clock.

16

SIM2_DATA

SIM2 card data I/O.

25

SIM2_RST

SIM2 card reset.

DCD

NOTE

M35 User Manual

The SIM interfaces are powered by an internal regulator in the module. Both 1.8V and 3.0V SIM Cards are supported.

Table 17: Pin Definition of the SIM Interfaces

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GSM/GPRS Module Series

VDD_EXT

Module

SIM1_VDD

SIM_GND

SIM1_RST SIM1_CLK

SIM1_DATA

SIM1_PRESENCE

22R

22R 22R

10K

100nF SIM_Holder

GND

TVS

33pF33pF 33pF33pF

VCC RST

CLK

IO

VPP

GND

Module

SIM1_VDD

SIM_GND

SIM1_RST SIM1_CLK

SIM1_DATA

SIM1_PRESENCE

22R

22R 22R

100nF

SIM_Holder

GND

TVS

33pF33pF33pF

VCC

RST CLK IO

VPP

GND

33pF

M35 User Manual

The following figure is the reference design for SIM1 interface.

Figure 33: Reference Circuit for SIM1 Interface with 8-pin SIM Card Holder

If SIM1 card detection function is not used, keep SIM1_PRESENCE pin open. The reference circuit for a 6-pin SIM card socket is illustrated as the following figure.

Figure 34: Reference Circuit for SIM1 Interface with the 6-pin SIM Card Holder

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GSM/GPRS Module Series

Module

SIM2_VDD

SIM_GND

SIM2_RST

SIM2_CLK

SIM2_DATA

22R

22R 22R

100nF

SIM_Holder

GND

TVS

33pF33pF33pF

VCC

RST CLK IO

VPP

GND

33pF

M35 User Manual

The following figure is the reference design for SIM2 interface with the 6-pin SIM card holder.

Figure 35: Reference Circuit for SIM2 Interface with the 6-pin SIM Card Holder

For more information of SIM card holder, you can visit http://www.amphenol.com and http://www.molex.com.

In order to enhance the reliability and availability of the SIM card in application. Please follow the below criteria 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 200mm.

 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 a TVS diode array. For more

information of TVS diode, you can visit http://www.onsemi.com/. The most important rule is to place your ESD protection device close to the SIM card socket and make sure the net being protected will go through the ESD device first and then lead to module. The 22Ω resistors should be connected 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.

 Place the RF bypass capacitors (33pF) close to the SIM card on all signals line for improving EMI.

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GSM/GPRS Module Series

If URC of SMS is disabled, the RI will not change.

RI

Idle Ring

Off-hook by“ATA”

On-hook by “ATH”

HIGH

LOW

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.

SMS

When a new SMS comes, the RI changes to LOW and holds low level for about 120ms, then changes to HIGH.

URC

Certain URCs can trigger 120ms low level on RI. For more details, please refer to the document [1].

NOTE

M35 User Manual

3.11. Behaviors of The RI

When using PCM interface, RI pin can be used as PCM_CLK.

Table 18: Behaviors of the RI

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 as below.

Figure 36: RI Behavior of Voice Calling as a Receiver

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GSM/GPRS Module Series

RI

Idle Calling

On-hook

Talking

HIGH

LOW

Idle

RI

Idle or

Talking

URC or

SMS received

HIGH

LOW

120ms

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

The GPRS data transmission after dialing the PPP connection.

M35 User Manual

Figure 37: RI Behavior as a Caller

Figure 38: RI Behavior of URC or SMS Received

3.12. 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 19: Working State of the NETLIGHT

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GSM/GPRS Module Series

Module

NETLIGHT

4.7K

47K

300R

VBAT

1)

When using PCM interface, STATUS pin can be used as PCM_SYNC.

Name

Description

1)

Alternate Function

STATUS

12

Indicate module operating status

PCM_SYNC

NOTE

M35 User Manual

A reference circuit is shown as below.

Figure 39: Reference Design for NETLIGHT

3.13. Operating Status Indication

The STATUS pin will output a high level after the module being turned on. but it is not recommended connecting this pin to a MCU’s GPIO to judge whether the module is turn-on or not. The following LED indicator circuit for STATUS pin can be used to indicate the state after the module has been turned on.

Table 20: Pin Definition of the STATUS

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GSM/GPRS Module Series

Module

STATUS

4.7K

47K

300R

VBAT

M35 User Manual

Figure 40: Reference Design for STATUS

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GSM/GPRS Module Series

Module

RF_ANT

0R

NM NM

Name

Description

GND

37

Ground

GND

38

Ground

RF_ANT

39

RF antenna pad

GND

40

Ground

M35 User Manual

4 Antenna Interface

The Pin 39 is the RF antenna pad. The RF interface has an impedance of 50Ω.

Table 21: Pin Definition of the RF_ANT

4.1. RF Reference Design

The reference design for RF is shown as below.

M35 provides an RF antenna pad for antenna connection. The RF trace in host PCB connected to the module RF antenna pad should be coplanar waveguide line or microstrip line, whose characteristic impedance should be close to 50Ω. M35 comes with grounding pads which are next to the antenna pad in

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Figure 41: Reference Design for RF

GSM/GPRS Module Series

In 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.

Frequency

Max.

Min.

GSM850

33dBm±2dB

5dBm±5dB

EGSM900

33dBm±2dB

5dBm±5dB

DCS1800

30dBm±2dB

0dBm±5dB

PCS1900

30dBm±2dB

0dBm±5dB

Frequency

Receive Sensitivity

GSM850

< -109dBm

EGSM900

< -109dBm

DCS1800

< -109dBm

PCS1900

< -109dBm

NOTE

M35 User Manual

order to give a better grounding. Besides, a π-type match circuit is suggested to be used to adjust the RF performance.

4.2. RF Output Power

Table 22: The Module Conducted RF Output Power

4.3. RF Receiving Sensitivity

Table 23: The Module Conducted RF Receiving Sensitivity

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GSM/GPRS Module Series

Type

Requirements

GSM850/EGSM900

Cable insertion loss <1dB

DCS1800/PCS1900

Cable insertion loss <1.5dB

Type

Requirements

Frequency Range

GSM850/EGSM900/DCS1800/PCS1900MHz.

VSWR

≤ 2

Gain (dBi)

1

Max Input Power (W)

50

Input Impedance (Ω)

50

Polarization Type

Vertical

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

M35 User Manual

4.4. Operating Frequencies

Table 24: The Module Operating Frequencies

4.5. Antenna Requirement

The following table shows the requirement on GSM antenna.

Table 25: Antenna Cable Requirements

Table 26: Antenna Requirements

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M35 User Manual

4.6. 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 42: RF Soldering Sample

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GSM/GPRS Module Series

Parameter

Min.

Max.

Unit

VBAT

-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

3.08

V

Voltage at Analog Pins

-0.3

3.08

V

Voltage at Digital/analog Pins in Power Down Mode

-0.25

0.25

V

Parameter

Min.

Typ.

Max.

Unit

Normal Temperature

-35

+25

+80

℃

M35 User Manual

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 27: Absolute Maximum Ratings

5.2. Operating Temperature

The operating temperature is listed in the following table:

Table 28: Operating Temperature

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GSM/GPRS Module Series

1)

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

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

Restricted Operation1)

-40 ~ -35

+80 ~ +85

℃

Storage Temperature

-45 +90

℃

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

Voltage drop during transmitting burst

Maximum power control level on GSM850 and EGSM900.

400

mV

I

VBAT

Average supply current

Power down mode SLEEP mode @DRX=5

150

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 mA

TALK mode GSM850/EGSM9001) DCS1800/PCS19002)

223/219 153/151

mA mA

DATA mode, GPRS (3Rx,2Tx) GSM850/EGSM9001) DCS1800/PCS19002)

363/393 268/257

mA mA

DATA mode, GPRS(2 Rx,3Tx) GSM850/EGSM9001) DCS1800/PCS19002)

506/546 366/349

mA mA

NOTE

M35 User Manual

5.3. Power Supply Ratings

Table 29: The Module Power Supply Ratings

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GSM/GPRS Module Series

1.

1)

Power control level PCL 5.

2.

2)

Power control level PCL 0.

3. Under the EGSM900 spectrum，the power of 1Rx and 4Tx has been reduced.

DATA mode, GPRS (4Rx,1Tx) GSM850/EGSM9001) DCS1800/PCS19002)

217/234 172/170

mA mA

DATA mode, GPRS (1Rx,4Tx) GSM850/EGSM9001) DCS1800/PCS19002)

458/485 462/439

mA mA

Peak supply current (during transmission slot)

Maximum power control level on GSM850 and EGSM900.

1.6 2 A

Condition

Current Consumption

Voice Call

GSM850

@power level #5 <300mA, Typical 223mA @power level #12, Typical 83mA @power level #19, Typical 62mA

EGSM900

@power level #5 <300mA, Typical 219mA @power level #12, Typical 83mA @power level #19, Typical 63mA

DCS1800

@power level #0 <250mA, Typical 153mA @power level #7, Typical 73mA @power level #15, Typical 60mA

PCS1900

@power level #0 <250mA, Typical 151mA @power level #7, Typical 76mA @power level #15, Typical 61mA

GPRS Data

NOTE

M35 User Manual

5.4. Current Consumption

The values of current consumption are shown as below.

Table 30: The Module Current Consumption

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GSM/GPRS Module Series

GPRS Class 10 is the default setting. The module can be configured from GPRS Class 1 to Class 10. Setting to lower GPRS class would make it easier to design the power supply for the module.

DATA Mode, GPRS ( 3 Rx, 2Tx ) CLASS 10

GSM850

@power level #5 <550mA, Typical 363mA @power level #12, Typical 131mA @power level #19, Typical 91mA

EGSM900

@power level #5 <550mA, Typical 393mA @power level #12, Typical 132mA @power level #19, Typical 92mA

DCS1800

@power level #0 <450mA, Typical 268mA @power level #7, Typical 112mA @power level #15, Typical 88mA

PCS1900

@power level #0 <450mA, Typical 257mA @power level #7, Typical 119mA @power level #15, Typical 89mA

DATA Mode, GPRS ( 4 Rx,1Tx ) CLASS 10

GSM850

@power level #5 <350mA, Typical 216mA @power level #12, Typical 103mA @power level #19, Typical 83mA

EGSM900

@power level #5 <350mA, Typical 233mA @power level #12, Typical 104mA @power level #19, Typical 84mA

DCS1800

@power level #0 <300mA, Typical 171mA @power level #7, Typical 96mA @power level #15, Typical 82mA

PCS1900

@power level #0 <300mA, Typical 169mA @power level #7, Typical 98mA @power level #15, Typical 83mA

NOTE

M35 User Manual

5.5. Electro-static Discharge

Although the GSM engine is generally protected against Electro-static 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 as the following table:

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GSM/GPRS Module Series

Tested Point

Contact Discharge

Air Discharge

VBAT,GND

±5KV

±10KV

RF_ANT

±5KV

±10KV

TXD, RXD

±2KV

±4KV

Others

±0.5KV

±1KV

M35 User Manual

Table 31: The ESD Endurance (Temperature: 25ºC , Humidity: 45%)

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GSM/GPRS Module Series

M35 User Manual

6 Mechanical Dimensions

This chapter describes the mechanical dimensions of the module.

6.1. Mechanical Dimensions of Module

Figure 43: M35 Module Top and Side Dimensions (Unit: mm)

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1

M35 User Manual

Figure 44: M35 Module Bottom Dimensions (Unit: mm)

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GSM/GPRS Module Series

frame line

B

A

frame line

Silksreen

The module should keep about 3mm away from other components in the host PCB.

NOTE

M35 User Manual

6.2. Recommended Footprint

Figure 45: Recommended Footprint (Unit: mm)

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GSM/GPRS Module Series

M35 User Manual

6.3. Top View of the Module

Figure 46: Top View of the Module

6.4. Bottom View of the Module

Figure 47: Bottom View of the Module

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GSM/GPRS Module Series

As plastic container cannot be subjected to high temperature, devices must be removed prior to high temperature (125ºC ) bake. If shorter bake times are desired, refer to the IPC/JEDECJ-STD-033 for bake procedure.

NOTE

M35 User Manual

7 Storage and Manufacturing

7.1. Storage

M35 module is distributed in a vacuum-sealed bag. The restriction for storage is shown as below.

Shelf life in the vacuum-sealed bag: 12 months at environments of <40ºC temperature and <90%RH.

After the vacuum-sealed bag is opened, devices that need to be mounted directly must be:

 Mounted within 72 hours at the factory environment of ≤30ºC temperature and <60% RH.  Stored at <10% RH.

Devices require baking before mounting, if any circumstance below occurs.

 When the ambient temperature is 23ºC ±5ºC , humidity indication card shows the humidity is >10%

before opening the vacuum-sealed bag.

 If ambient temperature is <30ºC and the humidity is <60%, the devices have not been mounted

during 72hours.

 Stored at >10% RH.

If baking is required, devices should be baked for 48 hours at 125ºC ±5ºC .

7.2. Soldering

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GSM/GPRS Module Series

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

M35 User Manual

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 0.2 mm for M35. For more details, please refer to document [5].

It is suggested that peak reflow temperature is from 235ºC to 245ºC (for SnAg3.0Cu0.5 alloy). Absolute max reflow temperature is 260ºC. 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.

Figure 48: Ramp-Soak-Spike Reflow Profile

7.3. Packaging

The modules 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.

7.3.1. Tape and Reel Packaging

The reel is 330mm in diameter and each reel contains 250 modules.

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GSM/GPRS Module Series

M35 User Manual

Figure 49: Tape and Reel Specification

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GSM/GPRS Module Series

PS

6

DETAIL:A

Model Name

MOQ for MP

Minimum Package: 250pcs

Minimum Package×4=1000pcs

M35

250pcs

Size: 370 × 350 × 56mm

3

N.W: 0.63kg G.W: 1.47kg

Size: 380 × 250 × 365mm

3

N.W: 2.5kg G.W: 6.4kg

M35 User Manual

Figure 50: Dimensions of Reel

Table 32: Reel Packing

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GSM/GPRS Module Series

SN

Document Name

Remark

[1]

Quectel_M35_AT_Commands_Manual

AT commands manual

[2]

ITU-T Draft new recommendation V.25ter

Serial asynchronous automatic dialing and control

[3]

GSM_UART_Application_Note

UART port application note

[4]

GSM_EVB_User_Guide

GSM EVB user guide

[5]

Module_Secondary_SMT_User_Guide

Module secondary SMT user guide

[6]

M35_Dual_SIM_Application_Notes_V3.0

M35 Dual SIM Application Notes

[7]

GSM_Multi_UART_Application_Note

M35 Multi UART Application Notes

[8]

Quectel_GSM_Module_Digital_IO_Application_Note

GSM module digital IO application note

[9]

GSM 07.07

Digital cellular telecommunications (Phase 2+); AT command set for GSM Mobile Equipment (ME)

[10]

GSM 07.10

Support GSM 07.10 multiplexing protocol

[11]

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)

[12]

GSM 11.14

Digital cellular telecommunications (Phase 2+); Specification of the SIM Application Toolkit for the Subscriber Identity module – Mobile Equipment (SIM – ME) interface

[13]

GSM 11.11

Digital cellular telecommunications (Phase 2+); Specification of the Subscriber Identity module – Mobile Equipment (SIM – ME) interface

M35 User Manual

8 Appendix A Reference

Table 33: Related Documents

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GSM/GPRS Module Series

[14]

GSM 03.38

Digital cellular telecommunications (Phase 2+); Alphabets and language-specific information

[15]

GSM 11.10

Digital cellular telecommunications (Phase

2); Mobile Station (MS) conformance specification; Part 1: Conformance specification

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

M35 User Manual

Table 34: Terms and Abbreviations

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GSM/GPRS Module Series

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

G.W

Gross Weight

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

Li-Ion

Lithium-Ion

MO

Mobile Originated

MOQ

Minimum Order Quantity

MP

Manufacture Product

MS

Mobile Station (GSM engine)

M35 User Manual

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GSM/GPRS Module Series

MT

Mobile Terminated

N.W

Net Weight

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

M35 User Manual

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GSM/GPRS Module Series

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

M35 User Manual

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GSM/GPRS Module Series

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

Rate 1/2 convolutional coding

Puncturing

456 bits

USF

BCS

Radio Block

M35 User Manual

9 Appendix B GPRS Coding Sche

me

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

Table 35: Description of Different Coding Schemes

Radio block structure of CS-1, CS-2 and CS-3 is shown as the figure below.

Figure 51: Radio Block Structure of CS-1, CS-2 and CS-3

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GSM/GPRS Module Series

Block

Code

No coding

456 bits

USF

BCS

Radio Block

M35 User Manual

Radio block structure of CS-4 is shown as the following figure.

Figure 52: Radio Block Structure of CS-4

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GSM/GPRS Module Series

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

8 4 1 5 9 3 2 5 10 4 2

5

M35 User Manual

10 Appendix C GPRS Multi-slot Class

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 the following table.

Table 36: GPRS Multi-slot Classes

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Quectel Wireless Solutions 201605M35 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual