Quectel Wireless Solutions 201604M26 Users Manual

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M26 Hardware Design

GSM/GPRS Module Series

Rev. M26_Hardware_Design_V1.1

Date: 2014-11-24

www.quectel.com

GSM/GPRS Module Series

M26 Hardware Design

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:

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

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.

Copyright © Quectel Wireless Solutions Co., Ltd. 2014. All rights reserved.

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About the Document

History

 

Revision

 

 

Date

 

Author

 

 

Description

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.0

 

2014-08-07

 

Felix YIN

 

Initial

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.

Modified output power of Bluetooth

 

 

 

 

 

 

 

 

2.

Modified the timing of the RFTXMON signal

 

 

 

 

 

 

 

 

3.

Updated Figure 5: Reference circuit for power

 

 

 

 

 

 

 

 

 

 

supply

 

 

 

 

 

 

 

 

4.

Modified description of RTC and SIM card

1.1

 

2014-11-24

 

Felix YIN

 

 

interface

 

 

5.

Modified description of UART Application

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6.

Deleted the over-voltage automatic shutdown

 

 

 

 

 

 

 

 

 

 

function

 

 

 

 

 

 

 

 

7.

Modified the antenna gain in the Table 24

 

 

 

 

 

 

 

 

8.

Modified the current consumption information in

 

 

 

 

 

 

 

 

 

 

Section 5.3 & 5.4

 

 

 

 

 

 

 

 

 

 

 

 

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Contents

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

 

2

Contents .......................................................................................................................................................

 

 

3

Table Index...................................................................................................................................................

 

 

6

Figure Index .................................................................................................................................................

 

 

7

1

Introduction

..........................................................................................................................................

 

9

 

1.1.

Safety Information....................................................................................................................

10

2

Product Concept ................................................................................................................................

 

11

 

2.1.

General Description.................................................................................................................

11

 

2.2.

Key Features

...........................................................................................................................

12

 

2.3.

Functional Diagram .................................................................................................................

14

 

2.4.

Evaluation Board .....................................................................................................................

14

3

Application Interface .........................................................................................................................

15

 

3.1.

Pin of Module...........................................................................................................................

16

 

 

3.1.1.

Pin Assignment ..............................................................................................................

16

 

 

3.1.2.

Pin Description ...............................................................................................................

17

 

3.2.

Operating Modes .....................................................................................................................

21

 

3.3.

Power Supply...........................................................................................................................

22

 

 

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

22

 

 

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

23

 

 

3.3.3. Reference Design For Power Supply ............................................................................

23

 

 

3.3.4.

Monitor Power Supply ....................................................................................................

24

 

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

24

 

 

3.4.1.

Power On .......................................................................................................................

24

 

 

3.4.2.

Power Down ...................................................................................................................

26

 

 

3.4.2.1.

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

26

 

 

3.4.2.2.

Power Down Module Using AT Command ........................................................

27

 

 

3.4.2.3.

Under-voltage Automatic Shutdown..................................................................

28

 

 

3.4.3.

Restart ............................................................................................................................

 

28

 

3.5.

Power Saving...........................................................................................................................

29

 

 

3.5.1.

Minimum Functionality Mode .........................................................................................

29

 

 

3.5.2.

SLEEP Mode..................................................................................................................

29

 

 

3.5.3. Wake Up Module From SLEEP Mode ...........................................................................

30

 

 

3.5.4.

Summary of State Transition..........................................................................................

30

 

3.6.

RTC Backup.............................................................................................................................

 

30

 

3.7.

Serial Interfaces.......................................................................................................................

32

 

 

3.7.1.

UART Port ......................................................................................................................

34

 

 

3.7.1.1.

The Feature of UART Port.................................................................................

34

 

 

3.7.1.2.

The Connection of UART ..................................................................................

35

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3.7.1.3.

Firmware Upgrade .............................................................................................

36

 

3.7.2.

 

Debug Port .....................................................................................................................

37

 

3.7.3.

 

Auxiliary UART Port .......................................................................................................

38

 

3.7.4.

 

UART Application ...........................................................................................................

38

 

3.8.

 

Audio Interfaces.......................................................................................................................

40

 

 

3.8.1. Decrease TDD Noise and other Noise ..........................................................................

41

 

3.8.2.

 

Microphone Interfaces Design .......................................................................................

41

 

 

3.8.3. Receiver and Speaker Interface Design ........................................................................

42

 

3.8.4.

 

Earphone Interface Design ............................................................................................

44

 

3.8.5.

 

Audio Characteristics .....................................................................................................

44

 

3.9.

 

PCM Interface..........................................................................................................................

45

 

3.9.1.

 

Configuration ..................................................................................................................

45

 

3.9.2.

 

.............................................................................................................................

46

 

3.9.3.

 

Reference .......................................................................................................... Design

48

 

3.9.4.

 

AT Command .................................................................................................................

48

 

3.10.

SIM Card Interface...................................................................................................................

49

 

3.11.

ADC

 

51

 

3.12.

Behaviors of .................................................................................................................The RI

51

 

3.13.

Network ........................................................................................................Status Indication

53

 

3.14.

RF Transmitting ............................................................................................Signal Indication

54

4

Antenna Interface...............................................................................................................................

 

56

 

4.1.

 

GSM ...........................................................................................................Antenna Interface

56

 

4.1.1.

..........................................................................................................

Reference Design

56

 

4.1.2.

...........................................................................................................

RF Output Power

57

 

4.1.3.

................................................................................................

RF Receiving Sensitivity

58

 

4.1.4.

...................................................................................................

Operating Frequencies

58

 

4.1.5.

........................................................................................................

RF Cable Soldering

59

 

4.2.

 

Bluetooth ....................................................................................................Antenna Interface

59

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

61

 

5.1.

 

Absolute .....................................................................................................Maximum Ratings

61

 

5.2.

 

Operating ............................................................................................................Temperature

61

 

5.3.

 

Power .............................................................................................................Supply Ratings

62

 

5.4.

 

Current ..............................................................................................................Consumption

63

 

5.5.

 

Electro ...........................................................................................................-static Discharge

65

6

Mechanical ....................................................................................................................Dimensions

66

 

6.1.

 

Mechanical ..........................................................................................Dimensions of Module

66

 

6.2.

 

Recommended .........................................................................................................Footprint

68

 

6.3.

 

Top View ...........................................................................................................of the Module

69

 

6.4.

 

Bottom ......................................................................................................View of the Module

69

7

Storage and ..............................................................................................................Manufacturing

70

 

7.1.

 

Storage.....................................................................................................................................

 

70

 

7.2.

 

Soldering..................................................................................................................................

 

71

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7.3. Packaging ................................................................................................................................

71

 

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

72

8

Appendix A Reference.......................................................................................................................

73

9

Appendix B GPRS Coding Scheme .................................................................................................

78

10

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

80

11

FCC Warning ......................................................................................................................................

81

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Table Index

 

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

12

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

13

TABLE 3: IO PARAMETERS DEFINITION........................................................................................................

17

TABLE 4: PIN DESCRIPTION ...........................................................................................................................

17

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

21

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

30

TABLE 7: LOGIC LEVELS OF THE UART INTERFACE ..................................................................................

33

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

33

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

40

TABLE 10: TYPICAL ELECTRET MICROPHONE CHARACTERISTICS.........................................................

44

TABLE 11: TYPICAL SPEAKER CHARACTERISTICS.....................................................................................

44

TABLE 12: PIN DEFINITION OF PCM INTERFACE.........................................................................................

45

TABLE 13: CONFIGURATION...........................................................................................................................

45

TABLE 14: QPCMON COMMAND DESCRIPTION ..........................................................................................

48

TABLE 15: QPCMVOL COMMAND DESCRIPTION.........................................................................................

49

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

49

TABLE 17: PIN DEFINITION OF THE ADC ......................................................................................................

51

TABLE 18: CHARACTERISTICS OF THE ADC................................................................................................

51

TABLE 19: BEHAVIORS OF THE RI .................................................................................................................

51

TABLE 20: WORKING STATE OF THE NETLIGHT..........................................................................................

53

TABLE 21: PIN DEFINITION OF THE RFTXMON ............................................................................................

54

TABLE 22: PIN DEFINITION OF THE RF_ANT ................................................................................................

56

TABLE 23: ANTENNA CABLE REQUIREMENTS.............................................................................................

57

TABLE 24: ANTENNA REQUIREMENTS..........................................................................................................

57

TABLE 25: THE MODULE CONDUCTED RF OUTPUT POWER ....................................................................

57

TABLE 26: THE MODULE CONDUCTED RF RECEIVING SENSITIVITY .......................................................

58

TABLE 27: THE MODULE OPERATING FREQUENCIES................................................................................

58

TABLE 28: PIN DEFINITION OF THE BT_ANT ................................................................................................

59

TABLE 29: ABSOLUTE MAXIMUM RATINGS ..................................................................................................

61

TABLE 30: OPERATING TEMPERATURE........................................................................................................

61

TABLE 31: THE MODULE POWER SUPPLY RATINGS ..................................................................................

62

TABLE 32: THE MODULE CURRENT CONSUMPTION ..................................................................................

63

TABLE 33: THE ESD ENDURANCE (TEMPERATURE: 25ºC, HUMIDITY: 45%) ............................................

65

TABLE 34: RELATED DOCUMENTS ................................................................................................................

73

TABLE 35: TERMS AND ABBREVIATIONS ......................................................................................................

74

TABLE 36: DESCRIPTION OF DIFFERENT CODING SCHEMES ..................................................................

78

TABLE 37: GPRS MULTI-SLOT CLASSES ......................................................................................................

80

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Figure Index

 

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

14

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

16

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

22

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

23

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

24

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

25

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

25

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

26

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

27

FIGURE 10: TIMING OF RESTARTING SYSTEM............................................................................................

28

FIGURE 11: VRTC IS SUPPLIED BY A NON-CHARGEABLE BATTERY ........................................................

31

FIGURE 12: VRTC IS SUPPLIED BY A RECHARGEABLE BATTERY ............................................................

31

FIGURE 13: VRTC IS SUPPLIED BY A CAPACITOR ......................................................................................

32

FIGURE 14: REFERENCE DESIGN FOR FULL-FUNCTION UART................................................................

35

FIGURE 15: REFERENCE DESIGN FOR UART PORT...................................................................................

36

FIGURE 16: REFERENCE DESIGN FOR UART PORT WITH HARDWARE FLOW CONTROL ....................

36

FIGURE 17: REFERENCE DESIGN FOR FIRMWARE UPGRADE.................................................................

37

FIGURE 18: REFERENCE DESIGN FOR DEBUG PORT ...............................................................................

37

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

38

FIGURE 20: LEVEL MATCH DESIGN FOR 3.3V SYSTEM..............................................................................

38

FIGURE 21: SKETCH MAP FOR RS-232 INTERFACE MATCH......................................................................

39

FIGURE 22: REFERENCE DESIGN FOR AIN .................................................................................................

41

FIGURE 23: HANDSET INTERFACE DESIGN FOR AOUT1 ...........................................................................

42

FIGURE 24: SPEAKER INTERFACE DESIGN WITH AN AMPLIFIER FOR AOUT1 .......................................

42

FIGURE 25: HANDSET INTERFACE DESIGN FOR AOUT2 ...........................................................................

43

FIGURE 26: SPEAKER INTERFACE DESIGN WITH AN AMPLIFIER FOR AOUT2 .......................................

43

FIGURE 27: EARPHONE INTERFACE DESIGN..............................................................................................

44

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

46

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

47

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

47

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

47

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

48

FIGURE 33: REFERENCE CIRCUIT FOR SIM INTERFACE WITH THE 6-PIN SIM CARD HOLDER ...........

50

FIGURE 34: RI BEHAVIOR OF VOICE CALLING AS A RECEIVER ................................................................

52

FIGURE 35: RI BEHAVIOR AS A CALLER .......................................................................................................

52

FIGURE 36: RI BEHAVIOR OF URC OR SMS RECEIVED .............................................................................

52

FIGURE 37: REFERENCE DESIGN FOR NETLIGHT .....................................................................................

53

FIGURE 38: RFTXMON SIGNAL DURING BURST TRANSMISSION .............................................................

54

FIGURE 39: RFTXMON SIGNAL DURING CALL.............................................................................................

55

FIGURE 40: REFERENCE DESIGN FOR GSM ANTENNA .............................................................................

56

FIGURE 41: RF SOLDERING SAMPLE ...........................................................................................................

59

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FIGURE 42: REFERENCE DESIGN FOR BLUETOOTH ANTENNA ...............................................................

60

FIGURE 43: M26 MODULE TOP AND SIDE DIMENSIONS (UNIT: MM) .........................................................

66

FIGURE 44: M26 MODULE BOTTOM DIMENSIONS (UNIT: MM)...................................................................

67

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

68

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

69

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

69

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

71

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

72

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

72

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

78

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

79

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M26 Hardware Design

1 Introduction

This document defines the M26 module and describes its hardware interface which are connected with the customer application and the air interface.

This document can help you quickly understand module interface specifications, electrical and mechanical details. Associated with application note and user guide, you can use M26 module to design and set up mobile applications easily.

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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 M26 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 customer failure to comply with these precautions.

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

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2 Product Concept

2.1. General Description

M26 is a Quad-band GSM/GPRS engine that works at frequencies of GSM850MHz, EGSM900MHz, DCS1800MHz and PCS1900MHz. The M26 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 15.8mm × 17.7mm × 2.3mm, 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.

M26 is an SMD type module with LCC package, which can be easily embedded into applications. It provides abundant hardware interfaces like PCM Interface.

Designed with power saving technique, the current consumption of M26 is as low as 1.3 mA in SLEEP mode when DRX is 5.

M26 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.

M26 supports Bluetooth interface, it is fully compliant with Bluetooth specification 3.0.

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

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2.2. Key Features

The following table describes the detailed features of M26 module.

Table 1: Module Key Features

 

 

Feature

 

Implementation

 

 

 

 

 

 

 

 

 

 

 

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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Quad-band: GSM850, EGSM900, DCS1800, PCS1900.

 

 

 

 

Frequency Bands

 

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 multi-slot class 12 (default)

 

 

 

 

GPRS Connectivity

 

GPRS multi-slot class 1~12 (configurable)

 

 

 

 

 

 

GPRS mobile station class B

 

 

 

 

 

 

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

 

 

 

 

DATA GPRS

 

Support the protocols PAP (Password Authentication

Protocol)

 

 

 

usually used for PPP connections

 

 

 

 

 

 

 

 

 

 

 

 

Internet service protocols TCP/UDP, FTP, PPP, HTTP, NTP, PING

 

 

 

 

Support Packet Broadcast Control Channel (PBCCH)

 

 

 

 

 

 

Support Unstructured Supplementary Service Data (USSD)

 

 

 

 

 

 

Normal operation: -35°C ~ +80°C

 

 

 

 

Temperature Range

 

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

 

 

 

 

 

 

Storage temperature: -45°C ~ +90°C

 

 

 

 

Bluetooth

 

Support Bluetooth specification 3.0

 

 

 

 

 

Output Power: Class 1 (Typical 7.5dBm)

 

 

 

 

 

 

 

 

 

 

SMS

 

Text and PDU mode

 

 

 

 

 

SMS storage: SIM card

 

 

 

 

 

 

 

 

 

 

SIM Interface

 

Support SIM card: 1.8V, 3.0V

 

 

 

 

 

 

 

 

 

 

 

 

 

Speech codec modes:

 

 

 

 

Audio Features

 

Half Rate (ETS 06.20)

 

 

 

 

 

 

Full Rate (ETS 06.10)

 

 

 

 

 

 

 

 

 

 

 

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Enhanced Full Rate (ETS 06.50/06.60/06.80)

 

Adaptive Multi-Rate (AMR)

 

Echo Suppression

 

Noise Reduction

 

 

 

UART Port:

 

Seven lines on UART port interface

 

Used for AT command, GPRS data

 

Multiplexing function

UART Interfaces

Support autobauding from 4800bps to 115200bps

Debug Port:

 

 

Two lines on debug port interface DBG_TXD and DBG_RXD

 

Debug Port only used for firmware debugging

 

Auxiliary Port:

 

Used for AT command

Phonebook Management

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

 

 

SIM Application Toolkit

Support SAT class 3, GSM 11.14 Release 99

 

 

Real Time Clock

Supported

 

 

Physical Characteristics

Size: 15.8±0.15 × 17.7±0.15 × 2.3±0.2mm

Weight: Approx. 1.3g

 

 

 

Firmware Upgrade

Firmware upgrade via UART Port

 

 

Antenna Interface

Connected to antenna pad with 50 Ohm impedance control

 

 

 

NOTE

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.

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

 

 

 

 

Coding Scheme

1 Timeslot

2 Timeslot

4 Timeslot

 

 

 

 

 

 

 

 

CS-1

9.05kbps

18.1kbps

36.2kbps

 

 

 

 

CS-2

13.4kbps

26.8kbps

53.6kbps

 

 

 

 

CS-3

15.6kbps

31.2kbps

62.4kbps

 

 

 

 

CS-4

21.4kbps

42.8kbps

85.6kbps

 

 

 

 

M26_Hardware_Design

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Quectel Wireless Solutions 201604M26 Users Manual

GSM/GPRS Module Series

M26 Hardware Design

2.3. Functional Diagram

The following figure shows a block diagram of M26 and illustrates the major functional parts.

Radio frequency part

Power management

The peripheral interface

—Power supply

—Turn-on/off interface

—UART interface

—Audio interface

—PCM interface

—SIM interface

—ADC interface

—RF interface

—BT interface

RF_ANT

 

 

 

 

 

 

ESD

RF

PAM

 

 

 

 

 

 

VBAT

 

 

 

 

 

 

PMU

 

RF Transceiver

26MHz

PWRKEY

 

 

 

 

 

 

 

 

 

BT

BT_ANT

VDD_EXT

VDD_EXT

 

 

 

 

 

 

 

 

Serial

UART

 

 

 

 

Interface

VRTC

RTC

 

 

 

BB&RF

 

 

 

 

 

 

SIM

SIM

 

 

AUDIO

AUDIO

 

 

 

 

Interface

Interface

 

 

 

 

 

 

 

 

PCM

PCM

NETLIGHT

PWM

MEMORY

ADC

ADC

 

Figure 1: Module Functional Diagram

2.4. Evaluation Board

In order to help you to develop applications with M26, 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 [11].

M26_Hardware_Design

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GSM/GPRS Module Series

M26 Hardware Design

3 Application Interface

The module adopts LCC package and has 44 pins. The following chapters provide detailed descriptions about these pins.

Pin of module

Operating modes

Power supply

Power on/down

Power saving

RTC

Serial interfaces

Audio interfaces

PCM interface

SIM card interface

ADC

Behaviors of the RI

Network status indication

RF transmitting signal indication

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M26 Hardware Design

3.1. Pin of Module

3.1.1. Pin Assignment

 

 

 

 

 

 

 

VRTC

VBAT

 

VBAT

 

GND

 

GND

TXD_DBG

 

RXD_DBG

 

GND

 

GND

 

 

 

 

 

 

 

 

 

 

 

44

 

43

 

 

42

 

41

 

40

 

39

 

38

 

37

 

36

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AGND

 

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

35

RF_ANT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SPK2P

 

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

34

GND

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MICP

 

3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

33

PCM_OUT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MICN

 

4

 

 

 

 

 

 

 

 

 

M26

 

 

 

 

 

 

 

 

32

PCM_IN

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SPK1P

 

5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

31

PCM_SYNC

 

 

 

 

 

 

 

 

 

 

 

Top View

 

 

 

 

 

 

 

 

 

 

 

SPK1N

 

6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

30

PCM_CLK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PWRKEY

 

7

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

29

TXD_AUX

 

 

AVDD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

28

RXD_AUX

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ADC0

 

9

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

27

GND

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SIM_GND

 

10

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

26

BT_ANT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SIM_DATA

 

11

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

25

RFTXMON

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SIM_RST

 

12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

24

VDD_EXT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SIM_CLK

 

13

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

23

RTS

 

 

 

 

 

 

 

14

 

15

 

 

16

 

17

 

18

 

19

 

20

 

21

 

22

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SIM_VDD

RESERVED

 

NETLIGHT

 

RXD

 

TXD

DTR

 

RI

 

DCD

 

CTS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

POWER GND

AUDIO

UART

 

SIM

 

PCM

 

 

ANT RESERVED OTHERS

Figure 2: Pin Assignment

NOTE

Keep all reserved pins open.

 

 

 

 

 

 

 

 

 

 

 

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GSM/GPRS Module Series

M26 Hardware Design

3.1.2. Pin Description

Table 3: IO Parameters Definition

 

 

Type

Description

 

 

IO

Bidirectional input/output

 

 

DI

Digital input

 

 

DO

Digital output

 

 

PI

Power input

 

 

PO

Power output

 

 

AI

Analog input

 

 

AO

Analog output

 

 

Table 4: Pin Description

Power Supply

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Make sure that

 

 

 

 

 

 

supply

 

 

 

 

Main power supply of

VImax=4.6V

sufficient

 

VBAT

42,43

PI

module:

VImin=3.3V

current in a

 

 

 

 

VBAT=3.3V~4.6V

VInorm=4.0V

transmitting

 

 

 

 

 

 

burst typically

 

 

 

 

 

 

rises to 1.6A.

 

 

 

 

 

 

 

 

 

 

 

 

 

VImax=3.3V

 

 

 

 

 

 

Power supply for RTC when

VImin=1.5V

 

 

 

 

 

 

VBAT is not supplied for the

VInorm=2.8V

 

 

 

VRTC

44

IO

system.

VOmax=3V

If unused, keep

 

Charging for backup battery or

VOmin=2V

this pin open.

 

 

 

 

 

 

 

 

golden capacitor when the

VOnorm=2.8V

 

 

 

 

 

 

VBAT is applied.

IOmax=2mA

 

 

 

 

 

 

 

Iin≈10uA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VOmax=2.9V

1. If unused,

 

 

 

 

 

keep this pin

 

VDD_

 

 

Supply 2.8V voltage for

VOmin=2.7V

 

24

PO

open.

 

EXT

external circuit.

VOnorm=2.8V

 

 

 

2. Recommend

 

 

 

 

 

IOmax=20mA

 

 

 

 

 

to add a

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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GSM/GPRS Module Series

M26 Hardware Design

 

 

 

 

2.2~4.7uF

 

 

 

 

bypass

 

 

 

 

capacitor,

 

 

 

 

when using

 

 

 

 

this pin for

 

 

 

 

power supply.

 

 

 

 

 

 

 

27,34

 

 

 

GND

36,37

Ground

 

 

 

40,41

 

 

 

 

 

 

 

 

Turn on/off

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No. I/O

Description

DC Characteristics Comment

 

 

 

Power on/off key. PWRKEY

PWRKEY

7

DI

should be pulled down for a

moment to turn on or turn off

 

 

 

the system.

VILmax=

0.1×VBAT

VIHmin=

0.6×VBAT

VIHmax=3.1V

Audio Interface

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

 

MICP

3,

 

Positive and negative voice

 

If unused, keep

 

AI

 

these pins

 

MICN

4

input

 

 

 

 

open.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SPK1P

5,

AO

Channel 1 positive and

 

If unused, keep

 

SPK1N

6

negative voice output

 

these pins

 

 

 

 

 

 

 

 

 

open.

 

 

 

 

 

 

 

 

 

 

 

Refer to Section 3.8

Support both

 

SPK2P

2

AO

Channel 2 voice output

 

voice and

 

 

 

 

 

 

ringtone

 

 

 

 

 

 

output.

 

 

 

 

 

 

 

 

 

 

 

Analog ground. Separate

 

If unused, keep

 

AGND

1

 

ground connection for

 

 

 

 

this pin open.

 

 

 

 

external audio circuits.

 

 

 

 

 

 

 

 

 

 

 

 

 

Network Status Indicator

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

 

 

 

 

 

VOHmin=

If unused,

 

 

 

 

 

0.85×VDD_EXT

 

NETLIGHT

16

DO

Network status indication

keep this pin

 

VOLmax=

 

 

 

 

 

open.

 

 

 

 

 

0.15×VDD_EXT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UART Port

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

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M26 Hardware Design

 

TXD

18

DO

Transmit data

VILmin=0V

 

 

 

 

 

 

 

 

 

VILmax=

 

 

RXD

17

DI

Receive data

 

 

0.25×VDD_EXT

If only use

 

 

 

 

 

 

 

 

 

 

VIHmin=

TXD, RXD and

 

DTR

19

DI

Data terminal ready

 

 

 

 

 

 

 

 

0.75×VDD_EXT

GND to

 

RI

20

DO

Ring indication

 

VIHmax=

communicate,

 

 

 

 

 

VDD_EXT+0.2

recommended

 

DCD

21

DO

Data carrier detection

 

VOHmin=

to keep other

 

 

 

 

 

 

 

 

 

 

 

CTS

22

DO

Clear to send

0.85×VDD_EXT

pins open.

 

 

 

 

 

VOLmax=

 

 

RTS

23

DI

Request to send

 

 

0.15×VDD_EXT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Debug Port

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

 

DBG_

39

DO

Transmit data

 

If unused,

 

TXD

 

 

 

 

 

Same as above

keep these

 

 

 

 

 

 

DBG_

 

 

 

 

38

DI

Receive data

 

pins open.

 

RXD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Auxiliary Port

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

 

TXD_

29

DO

Transmit data

 

If unused,

 

AUX

 

 

 

 

 

Same as above

keep these

 

 

 

 

 

 

RXD_

 

 

 

 

28

DI

Receive data

 

pins open.

 

AUX

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SIM Interface

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

The voltage can be

SIM_ VDD

14

PO

Power supply for SIM card

selected by software

automatically. Either

 

 

 

 

 

 

 

 

1.8V or 3.0V.

 

 

 

 

 

 

 

 

 

VOLmax=

SIM_ CLK

13

DO

SIM clock

0.15×SIM_VDD

VOHmin=

 

 

 

 

 

 

 

 

0.85×SIM_VDD

 

 

 

 

 

 

 

 

 

VILmax=

 

 

 

 

0.25×SIM_VDD

 

 

 

 

VIHmin=

SIM_ DATA

11

IO

SIM data

0.75×SIM_VDD

VOLmax=

0.15×SIM_VDD

VOHmin=

0.85×SIM_VDD

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

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GSM/GPRS Module Series

M26 Hardware Design

 

 

 

 

 

 

VOLmax=

 

 

 

 

SIM_ RST

12

DO

SIM reset

0.15×SIM_VDD

 

 

 

 

VOHmin=

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.85×SIM_VDD

 

 

 

 

 

 

 

 

 

 

 

 

 

SIM_

10

 

SIM ground

 

 

 

 

 

GND

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ADC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reference voltage of

VOmax=2.9V

If unused,

 

 

AVDD

8

PO

VOmin=2.7V

keep this pin

 

 

ADC circuit

 

 

 

 

 

VOnorm=2.8V

open.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

General purpose analog to

Voltage range:

If unused,

 

 

ADC0

9

AI

keep this pin

 

 

digital converter.

0V to 2.8V

 

 

 

 

 

open.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PCM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

 

 

 

 

PCM_ CLK

30

DO

PCM clock

VILmin= 0V

 

 

 

 

 

 

 

 

 

 

 

 

 

VILmax=

 

 

 

 

PCM_

 

 

PCM frame

 

 

 

 

31

DO

0.25×VDD_EXT

 

 

 

 

SYNC

synchronization

 

 

 

 

 

 

VIHmin=

 

 

 

 

 

 

 

 

 

 

 

 

PCM_

 

 

 

 

 

 

 

32

DI

PCM data input

0.75×VDD_EXT

If unused,

 

 

 

 

 

IN

 

 

 

 

 

 

 

 

VIHmax=

keep this pin

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VDD_EXT+0.2

open.

 

 

PCM_

 

 

 

VOHmin=

 

 

 

 

33

DO

PCM data output

0.85×VDD_EXT

 

 

 

 

OUT

 

 

 

 

 

 

 

VOLmax=

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.15×VDD_EXT

 

 

 

 

 

 

 

 

 

 

 

 

Antenna Interface

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

 

 

 

 

RF_

35

IO

GSM antenna pad

Impedance of 50Ω

 

 

 

 

ANT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BT_

 

 

 

 

If unused,

 

 

26

IO

BT antenna pad

Impedance of 50Ω

keep this pin

 

 

ANT

 

 

 

 

 

 

open.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Transmitting Signal Indication

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No.

I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Transmission signal

VOHmin=

If unused,

 

 

RFTXMON

25

DO

0.85×VDD_EXT

keep this pin

 

 

indication

 

 

 

 

 

VOLmax=

open.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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M26 Hardware Design

 

 

 

 

0.15×VDD_EXT

 

 

 

 

 

 

 

Other Interface

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PIN Name

PIN No. I/O

Description

DC Characteristics

Comment

 

 

 

 

 

 

 

RESERVED

15

 

 

Keep these

 

 

 

pins open.

 

 

 

 

 

 

 

 

 

 

 

3.2. Operating Modes

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

Table 5: Overview of Operating Modes

 

Mode

 

Function

 

 

 

 

 

 

 

 

 

 

After enabling sleep mode by AT+QSCLK=1, the module will

 

 

 

 

automatically enter into Sleep Mode if DTR is set to high level

 

 

 

GSM/GPRS

and there is no interrupt (such as GPIO interrupt or data on

 

 

 

UART port). In this case, the current consumption of module

 

 

 

Sleep

 

 

 

will reduce to the minimal level.

 

 

 

 

 

 

 

 

During Sleep Mode, the module can still receive paging

 

 

 

 

message and SMS from the system normally.

 

 

 

 

 

 

 

 

 

Software is active. The module has registered to the GSM

 

 

 

GSM IDLE

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

 

 

 

 

data.

 

 

 

 

 

 

 

 

 

GSM connection is ongoing. In this mode, the power

 

Normal Operation

 

GSM TALK

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

The module is registered to GPRS network, but no GPRS PDP

 

 

 

context is active. The SGSN knows the Routing Area where the

 

 

 

STANDBY

 

 

 

module is located at.

 

 

 

 

 

 

 

 

 

 

 

 

 

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

 

 

 

GPRS READY

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

 

 

 

 

knows the cell where the module is located at.

 

 

 

 

 

 

 

 

 

There is GPRS data in transfer. In this mode, power

 

 

 

GPRS DATA

consumption is decided by the PCL, working RF band and

 

 

 

 

GPRS multi-slot configuration.

 

 

 

 

 

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M26 Hardware Design

Normal shutdown by sending the AT+QPOWD=1 command or using the PWRKEY pin. The power management ASIC disconnects the power supply from POWER DOWN 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

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

Functionality Mode

without removing the power supply. In this case, the RF part of the module will not

(without removing

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

power supply)

disabled, but the UART port is still accessible. The power consumption in this case is very low.

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 the M26 module, the max current consumption could reach to 1.6A during a burst transmission. 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 burst transmission does not exceed 400mV.

4.615ms

577us

Burst:1.6A

IBAT

VBAT

Vdrop

Figure 3: Voltage Ripple during Transmitting

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M26 Hardware Design

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 burst transmission. 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 burst transmission. The width of trace should be no less than 2mm and the principle of the VBAT route is the longer route, the wider trace.

VBAT

+

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C1

 

C2

C3

C4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

100uF

 

100nF

10pF

33pF

 

 

 

 

 

 

 

 

 

 

 

0603

 

0603

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GND

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 use as a power supply.

The following figure 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 whose reverse zener voltage is 5.1V and dissipation power is more than 1 Watt.

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GSM/GPRS Module Series

M26 Hardware Design

MIC29302WU U1

DC_IN

2 IN

C1

 

 

C2

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

470uF

 

 

100nF

 

 

 

 

 

51K

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4.7K

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MCU_POWER_ON/OFF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

47K

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VBAT

 

 

OUT 4

 

 

 

 

 

 

 

 

R2

 

 

 

 

EN

3 GND

5 ADJ

124K

 

C3

C4

 

 

R4

D1

 

 

 

 

 

 

 

R3

470R

470uF

100nF

5.1V

 

 

 

56K

 

 

 

 

 

 

 

Figure 5: Reference Circuit for Power Supply

NOTE

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.

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.

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