Quectel MC20 Hardware Design V1.0

MC20 Hardware Design
GSM/GPRS/GNSS Module Series
Rev. MC20_Hardware_Design_V1.0
Date: 2016-07-12
www.quectel.com
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Or email to: Support@quectel.com
GENERAL NOTES
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QUECTEL OFFERS THE INFORMATION AS A SERVICE TO ITS CUSTOMERS. THE INFORMATION
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COPYRIGHT
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Copyright © Quectel Wireless Solutions Co., Ltd. 2016. All rights reserved.
MC20_Hardware_Design Confidential / Released 1 / 93

About the Document
History
Revision Date
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1.0 2016-07-12 Tiger CHENG Initial
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Contents
About the Document ................................................................................................................................... 2

Contents ....................................................................................................................................................... 3
Table Index ................................................................................................................................................... 6
Figure Index ................................................................................................................................................. 8
1 Introduction ........................................................................................................................................ 10
1.1. Safety Information.................................................................................................................... 10
2 Product Concept ................................................................................................................................ 12
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2.1. General Description ................................................................................................................. 12
2.2. Key Features ........................................................................................................................... 13
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2.3. Functional Diagram ................................................................................................................. 16
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2.4. Evaluation Board ..................................................................................................................... 17
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3 Application Functions ....................................................................................................................... 18
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3.1. Pin of Module ........................................................................................................................... 19
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3.1.1. Pin Assignment .............................................................................................................. 19
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3.1.2. Pin Description ............................................................................................................... 20
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3.2. Application Modes Introduction ............................................................................................... 24
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3.3. Power Supply........................................................................................................................... 26
3.3.1. Power Features .............................................................................................................. 26
3.3.2. Decrease Supply Voltage Drop ...................................................................................... 27
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3.3.2.1. Decrease Supply Voltage Drop for GSM Part ................................................... 27
3.3.2.2. Decrease Supply Voltage Drop for GNSS Part ................................................. 28
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3.3.3. Reference Design for Power Supply .............................................................................. 29
3.3.3.1. Reference Design for Power Supply of GSM Part ............................................ 29
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3.3.3.2. Reference Design for Power Supply of GNSS Part .......................................... 30
3.3.4. Monitor Power Supply .................................................................................................... 30
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3.3.5. Backup Domain of GNSS .............................................................................................. 30
3.4. Operating Modes ..................................................................................................................... 31
3.4.1. Operating Modes of GSM Part....................................................................................... 31
3.4.1.1. Minimum Functionality Mode............................................................................. 32
3.4.1.2. SLEEP Mode ..................................................................................................... 33
3.4.1.3. Wake up GSM Part from SLEEP Mode............................................................. 33
3.4.2. Operating Modes of GNSS Part..................................................................................... 33
3.4.2.1. Full on Mode ...................................................................................................... 33
3.4.2.2. Standby Mode.................................................................................................... 35
3.4.2.3. Backup Mode..................................................................................................... 35
3.4.3. Summary of GSM and GNSS Parts’ State in All-in-one Solution................................... 36
3.4.4. Summary of GSM and GNSS Parts’ State in Stand-alone Solution .............................. 36
3.5. Power on and down ................................................................................................................. 37
3.5.1. Power on ........................................................................................................................ 37
3.5.2. Power down.................................................................................................................... 39

3.5.2.1. Power down Module Using the PWRKEY Pin .................................................. 39

3.5.2.2. Power down Module Using AT Command......................................................... 40
3.5.2.3. Power down GNSS Part Alone Using AT Command ........................................ 41
3.5.2.4. Under-voltage Automatic Shutdown .................................................................. 41
3.6. Serial Interfaces ....................................................................................................................... 42
3.6.1. UART Port ...................................................................................................................... 44
3.6.1.1. Features of UART Port ...................................................................................... 44
3.6.1.2. The Connection of UART .................................................................................. 45
3.6.1.3. Firmware Upgrade ............................................................................................. 47
3.6.2. Debug Port ..................................................................................................................... 48
3.6.3. Auxiliary UART Port and GNSS UART Port .................................................................. 48
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3.6.3.1. Connection in All-in-one Solution ...................................................................... 48
3.6.3.2. Connection in Stand-alone Solution .................................................................. 49
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3.6.4. UART Application ........................................................................................................... 50
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3.7. Audio Interfaces ....................................................................................................................... 51
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3.7.1. Decrease TDD Noise and Other Noises ........................................................................ 53
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3.7.2. Microphone Interfaces Design ....................................................................................... 53
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3.7.3. Receiver and Speaker Interface Design ........................................................................ 54
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3.7.4. Earphone Interface Design ............................................................................................ 55
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3.7.5. Loud Speaker Interface Design...................................................................................... 55
3.7.6. Audio Characteristics ..................................................................................................... 56
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3.8. SIM Card Interface................................................................................................................... 56
3.9. ADC ......................................................................................................................................... 60
3.10. Behaviors of the RI .................................................................................................................. 60
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3.11. Network Status Indication ........................................................................................................ 62
3.12. EASY Autonomous AGPS Technology ................................................................................... 63
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3.13. EPO Offline AGPS Technology................................................................................................ 63
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3.14. Multi-tone AIC .......................................................................................................................... 64
4 Antenna Interface ............................................................................................................................... 65
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4.1. GSM Antenna Interface ........................................................................................................... 65
4.1.1. Reference Design .......................................................................................................... 65
4.1.2. RF Output Power ........................................................................................................... 66
4.1.3. RF Receiving Sensitivity ................................................................................................ 67
4.1.4. Operating Frequencies................................................................................................... 67
4.1.5. RF Cable Soldering ........................................................................................................ 67
4.2. GNSS Antenna Interface ......................................................................................................... 68
4.2.1. Antenna Specifications ................................................................................................... 68
4.2.2. Active Antenna ............................................................................................................... 69
4.2.3. Passive Antenna ............................................................................................................ 70
4.3. Bluetooth Antenna Interface .................................................................................................... 70
5 Electrical, Reliability and Radio Characteristics ............................................................................ 72

5.1. Absolute Maximum Ratings ..................................................................................................... 72
5.2. Operating Temperature ............................................................................................................ 72

5.3. Power Supply Ratings ............................................................................................................. 73

5.4. Current Consumption .............................................................................................................. 75
5.5. Electrostatic Discharge ............................................................................................................ 77
6 Mechanical Dimensions .................................................................................................................... 79

6.1. Mechanical Dimensions of Module.......................................................................................... 79
6.2. Recommended Footprint ......................................................................................................... 81
6.3. Top and Bottom View of the Module........................................................................................ 82
7 Storage and Manufacturing .............................................................................................................. 83

7.1. Storage..................................................................................................................................... 83
7.2. Soldering .................................................................................................................................. 83
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7.3. Packaging ................................................................................................................................ 84
7.3.1. Tape and Reel Packaging .............................................................................................. 85
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8 Appendix A References..................................................................................................................... 86
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9 Appendix B GPRS Coding Schemes ............................................................................................... 91
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10 Appendix C GPRS Multi-slot Classes .............................................................................................. 93
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Table Index
TABLE 1: KEY FEATURES (GMS/GPRS PART OF MC20) ...................................................................... 13

TABLE 2: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE ................ 15
TABLE 3: KEY FEATURES (GNSS PART OF MC20) ............................................................................... 15
TABLE 4: PROTOCOLS SUPPORTED BY THE MODULE ...................................................................... 16
TABLE 5: I/O PARAMETERS DEFINITION ............................................................................................... 20
TABLE 6: PIN DESCRIPTION ................................................................................................................... 20
TABLE 7: MULTIPLEXED FUNCTIONS .................................................................................................... 24
TABLE 8: COMPARISON BETWEEN ALL-IN-ONE AND STAND-ALONE SOLUTION ............................ 26
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TABLE 9: OPERATING MODES OVERVIEW OF GSM PART ................................................................. 31
TABLE 10: DEFAULT CONFIGURATION OF FULL ON MODE (GNSS PART)........................................ 34
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TABLE 11: COMBINATION STATES OF GSM AND GNSS PARTS IN ALL-IN-ONE SOLUTION ............ 36
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TABLE 12: COMBINATION STATES OF GSM AND GNSS PARTS IN STAND-ALONE SOLUTION ...... 36
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TABLE 13: LOGIC LEVELS OF THE UART INTERFACE ......................................................................... 43
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TABLE 14: PIN DEFINITION OF THE UART INTERFACES..................................................................... 43
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TABLE 15: PIN DEFINITION OF AUDIO INTERFACE .............................................................................. 51
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TABLE 16: AOUT2 OUTPUT CHARACTERISTICS .................................................................................. 52
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TABLE 17: TYPICAL ELECTRET MICROPHONE CHARACTERISTICS ................................................. 56
TABLE 18: TYPICAL SPEAKER CHARACTERISTICS ............................................................................. 56
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TABLE 19: PIN DEFINITION OF THE SIM INTERFACE .......................................................................... 57
TABLE 20: PIN DEFINITION OF THE ADC ............................................................................................... 60
TABLE 21: CHARACTERISTICS OF THE ADC ........................................................................................ 60
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TABLE 22: BEHAVIORS OF THE RI ......................................................................................................... 60
TABLE 23: WORKING STATE OF THE NETLIGHT .................................................................................. 62
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TABLE 24: PIN DEFINITION OF THE RF_ANT ........................................................................................ 65
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TABLE 25: ANTENNA CABLE REQUIREMENTS ..................................................................................... 66
TABLE 26: ANTENNA REQUIREMENTS .................................................................................................. 66
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TABLE 27: RF OUTPUT POWER .............................................................................................................. 66
TABLE 28: RF RECEIVING SENSITIVITY ................................................................................................ 67
TABLE 29: OPERATING FREQUENCIES ................................................................................................. 67
TABLE 30: RECOMMENDED ANTENNA SPECIFICATIONS ................................................................... 68
TABLE 31: PIN DEFINITION OF THE BT_ANT ........................................................................................ 71
TABLE 32: ABSOLUTE MAXIMUM RATINGS........................................................................................... 72
TABLE 33: OPERATING TEMPERATURE ................................................................................................ 73
TABLE 34: POWER SUPPLY RATINGS OF GSM PART (GNSS IS POWERED OFF) ........................... 73
TABLE 35: POWER SUPPLY RATINGS OF GNSS PART ........................................................................ 74
TABLE 36: CURRENT CONSUMPTION OF GSM PART (GNSS IS POWERED OFF) ........................... 75
TABLE 37: CURRENT CONSUMPTION OF THE GNSS PART ............................................................... 77
TABLE 38: ESD ENDURANCE (TEMPERATURE: 25ºC, HUMIDITY: 45%) ............................................ 77
TABLE 39: REEL PACKAGING.................................................................................................................. 85
TABLE 40: RELATED DOCUMENTS ........................................................................................................ 86
TABLE 41: TERMS AND ABBREVIATIONS .............................................................................................. 87

TABLE 42: DESCRIPTION OF DIFFERENT CODING SCHEMES .......................................................... 91

TABLE 43: GPRS MULTI-SLOT CLASSES ............................................................................................... 93
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Figure Index
FIGURE 1: MODULE FUNCTIONAL DIAGRAM ....................................................................................... 17

FIGURE 2: PIN ASSIGNMENT .................................................................................................................. 19
FIGURE 3: ALL-IN-ONE SOLUTION SCHEMATIC DIAGRAM ................................................................. 25
FIGURE 4: STAND-ALONE SOLUTION SCHEMATIC DIAGRAM ........................................................... 25
FIGURE 5: VOLTAGE RIPPLE DURING TRANSMITTING (GSM PART) ................................................ 27
FIGURE 6: REFERENCE CIRCUIT FOR THE VBAT INPUT (GSM PART).............................................. 28
FIGURE 7: REFERENCE CIRCUIT FOR THE GNSS_VCC INPUT ......................................................... 28
FIGURE 8: REFERENCE CIRCUIT FOR POWER SUPPLY OF THE GSM PART .................................. 29
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FIGURE 9: REFERENCE CIRCUIT DESIGN FOR GNSS PART ............................................................. 30
FIGURE 10: INTERNAL GNSS’S BACKUP DOMAIN POWER CONSTRUCTION .................................. 31
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FIGURE 11: TURN ON THE MODULE WITH AN OPEN-COLLECTOR DRIVER .................................... 37
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FIGURE 12: TURN ON THE MODULE WITH A BUTTON ........................................................................ 38
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FIGURE 13: TURN-ON TIMING ................................................................................................................ 38
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FIGURE 14: TURN-OFF TIMING BY USING THE PWRKEY PIN ............................................................ 40
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FIGURE 15: TURN-OFF TIMING OF GNSS PART BY USING AT COMMAND ....................................... 41
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FIGURE 16: REFERENCE DESIGN FOR FULL-FUNCTION UART ........................................................ 46
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FIGURE 17: REFERENCE DESIGN FOR UART PORT (THREE LINE CONNECTION) ........................ 46
FIGURE 18: REFERENCE DESIGN FOR UART PORT WITH HARDWARE FLOW CONTROL ............ 47
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FIGURE 19: REFERENCE DESIGN FOR FIRMWARE UPGRADE ......................................................... 47
FIGURE 20: REFERENCE DESIGN FOR DEBUG PORT ........................................................................ 48
FIGURE 21: AUXILIARY AND GNSS UART PORT CONNECTION IN ALL-IN-ONE SOLUTION ........... 49
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FIGURE 22: AUXILIARY AND GNSS UART PORT CONNECTION IN STAND-ALONE SOLUTION ...... 50
FIGURE 23: LEVEL MATCH DESIGN FOR 3.3V SYSTEM ...................................................................... 50
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FIGURE 24: SKETCH MAP FOR RS-232 INTERFACE MATCH .............................................................. 51
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FIGURE 25: REFERENCE DESIGN FOR AIN .......................................................................................... 53
FIGURE 26: HANDSET INTERFACE DESIGN FOR AOUT1 ................................................................... 54
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FIGURE 27: SPEAKER INTERFACE DESIGN WITH AN AMPLIFIER FOR AOUT1 ............................... 54
FIGURE 28: EARPHONE INTERFACE DESIGN ...................................................................................... 55
FIGURE 29: LOUD SPEAKER INTERFACE DESIGN .............................................................................. 55
FIGURE 30: REFERENCE CIRCUIT FOR SIM1 INTERFACE WITH AN 8-PIN SIM CARD HOLDER ... 58
FIGURE 31: REFERENCE CIRCUIT FOR SIM1 INTERFACE WITH A 6-PIN SIM CARD HOLDER ...... 58
FIGURE 32: REFERENCE CIRCUIT FOR SIM2 INTERFACE WITH A 6-PIN SIM CARD HOLDER ...... 59
FIGURE 33: RI BEHAVIOR AS A RECEIVER WHEN VOICE CALLING .................................................. 61
FIGURE 34: RI BEHAVIOR AS A CALLER ................................................................................................ 61
FIGURE 35: RI BEHAVIOR WHEN URC OR SMS RECEIVED................................................................ 61
FIGURE 36: REFERENCE DESIGN FOR NETLIGHT .............................................................................. 62
FIGURE 37: REFERENCE DESIGN FOR GSM ANTENNA ..................................................................... 65
FIGURE 38: RF SOLDERING SAMPLE .................................................................................................... 68
FIGURE 39: REFERENCE DESIGN WITH ACTIVE ANTENNA ............................................................... 69
FIGURE 40: REFERENCE DESIGN WITH PASSIVE ANTENNA............................................................. 70
FIGURE 41: REFERENCE DESIGN FOR BLUETOOTH ANTENNA ....................................................... 71

FIGURE 42: MC20 TOP AND SIDE DIMENSIONS (UNIT: MM) ............................................................... 79
FIGURE 43: MC20 BOTTOM DIMENSIONS (UNIT: MM) ......................................................................... 80
FIGURE 44: RECOMMENDED FOOTPRINT (UNIT: MM) ........................................................................ 81
FIGURE 45: TOP VIEW OF THE MODULE .............................................................................................. 82
FIGURE 46: BOTTOM VIEW OF THE MODULE ...................................................................................... 82
FIGURE 47: REFLOW SOLDERING THERMAL PROFILE ...................................................................... 84
FIGURE 48: TAPE AND REEL SPECIFICATION ...................................................................................... 85
FIGURE 49: DIMENSIONS OF REEL ....................................................................................................... 85
FIGURE 50: RADIO BLOCK STRUCTURE OF CS-1, CS-2 AND CS-3 ................................................... 91
FIGURE 51: RADIO BLOCK STRUCTURE OF CS-4 ............................................................................... 92
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1 Introduction
This document defines the MC20 module and describes its hardware interface which is connected with
the customer application as well as its air interface.
The document can help you quickly understand module interface specifications, as well as the electrical
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and mechanical details. Associated with application note and user guide, you can use MC20 module to
design and set up mobile applications easily.
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1.1. Safety Information
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The following safety precautions must be observed during all phases of the operation, such as usage,
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service or repair of any cellular terminal or mobile incorporating MC20 module. Manufacturers of the
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cellular terminal should send the following safety information to users and operating personnel, and
incorporate these guidelines into all manuals supplied with the product. If not so, Quectel assumes no
liability for the customer’s failure to comply with these precautions.
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Full attention must be given to driving at all times in order to reduce the risk of an
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accident. Using a mobile while driving (even with a handsfree kit) causes
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distraction and can lead to an accident. You must comply with laws and regulations
restricting the use of wireless devices while driving.
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Switch off the cellular terminal or mobile before boarding an aircraft. Make sure it is
switched off. The operation of wireless appliances in an aircraft is forbidden, so as
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, clinics or other health care
facilities. These requests are desinged to prevent possible interference with
sentitive medical equipment.

Cellular terminals or mobiles operating over radio frequency signal and cellular
network cannot be guaranteed to connect in all conditions, for example no mobile
fee or with 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 a 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.
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In locations with potencially explosive atmospheres, obey all posted signs to turn
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off wireless devices such as your phone or other cellular terminals. Areas with
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potencially explosive atmospheres include fuelling areas, below decks on boats,
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fuel or chemical transfer or storage facilities, areas where the air contains
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chemicals or particles such as grain, dust or metal powders, etc.
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2 Product Concept
2.1. General Description
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MC20 is a multi-purpose module which integrates a high performance GNSS engine and a quad-band
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GSM/GPRS engine. It can work as all-in-one solution or stand-alone solution according to customers'
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application demands. For detailed introduction on all-in-one solution and stand-alone solution, please
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refer to Chapter 3.2.
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The quad-band GSM/GPRS engine can work at frequencies of GSM850MHz, EGSM900MHz,
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DCS1800MHz and PCS1900MHz. MC20 features GPRS multi-slot class 12 and supports the GPRS
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coding schemes CS-1, CS-2, CS-3 and CS-4. For more details about GPRS multi-slot classes and coding
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schemes, please refer to the Appendix B & C.
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The GNSS engine is a single receiver integrating GPS and BeiDou systems. It supports multiple
positioning and navigation systems including autonomous GPS, BeiDou, SBAS (including WAAS,
EGNOS, MSAS and GAGAN), and QZSS. It is able to achieve the industry’s highest level of sensitivity,
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accuracy and TTFF with the lowest power consumption. The embedded flash memory provides capacity
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for storing user-specific configurations and allows for future updates.
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MC20 is an SMD type module with 54 LCC pads and 14 LGA pads which can be easily embedded into
applications. With a compact profile of 18.7mm × 16.0mm × 2.1mm, the module can meet almost all the
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requirements for M2M applications, including vehicle and personal tracking, wearable devices, security
systems, wireless POS, industrial PDA, smart metering, remote maintenance & control, etc.
Designed with power saving technique, the current consumption of MC20’s GSM part is as low as 1.2mA
in SLEEP mode when DRX is 5 and the GNSS part is powered off. The GNSS engine also has many
advanced power saving modes including standby and backup modes which can fit the requirement of
low-power consumption in different scenes.
GSM part of MC20 is integrated with Internet service protocols such as TCP, UDP, PPP, HTTP and FTP.
Extended AT commands have been developed for you to use these Internet service protocols easily.
EASY technology as a key feature of GNSS part of MC20 module is one kind of AGPS. Capable of
collecting and processing all internal aiding information like GNSS time, ephemeris, last position, etc., the
GNSS part will have a fast TTFF in either Hot or Warm start.

The module fully complies with the RoHS directive of the European Union.
2.2. Key Features
The following table describes the detailed features of MC20 module.
Table 1: Key Features (GMS/GPRS Part of MC20)
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Features Implementation
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Single supply voltage: 3.3V ~ 4.6V
Power Supply
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Typical supply voltage: 4V
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Typical power consumption in SLEEP mode (GNSS is powered off):
Power Saving 1.2mA@DRX=5
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0.8mA@DRX=9
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 Quad-band: GSM850, EGSM900, DCS1800, PCS1900.
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 The module can search these frequency bands automatically
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Frequency Bands
 The frequency bands can be set by AT commands
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 Compliant to GSM Phase 2/2+
GSM Class Small MS
 Class 4 (2W) at GSM850 and EGSM900
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Transmitting Power
 Class 1 (1W) at DCS1800 and PCS1900
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 GPRS multi-slot class 12 (default)
GPRS Connectivity  GPRS multi-slot class 1~12 (configurable)
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 GPRS mobile station class B
 GPRS data downlink transfer: max. 85.6kbps
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 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)
DATA GPRS
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)
 Operation temperature range: -35°C ~ +75°C 1)
Temperature Range
 Extended temperature range: -40°C ~ +85°C 2)
 Text and PDU mode
SMS
 SMS storage: SIM card
 Support SIM card: 1.8V, 3.0V
SIM Interface
 Support Dual SIM Single Standby

Speech codec modes:

 Half Rate (ETS 06.20)
 Full Rate (ETS 06.10)
 Enhanced Full Rate (ETS 06.50/06.60/06.80)
Audio Features  Adaptive Multi-Rate (AMR)
 Echo Suppression
 Noise Reduction
 Embedded one amplifier of class AB with maximum driving power up
to 800mW
UART Port:
 Seven lines on UART port interface
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 Used for AT command and GPRS data
 Used for PMTK command and NMEA output in all-in-one solution
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 Multiplexing function
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 Support autobauding from 4800bps to 115200bps
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UART Interfaces
Debug Port:
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 Two lines on debug port interface DBG_TXD and DBG_RXD
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 Debug port only used for firmware debugging
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Auxiliary Port:
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 Two lines on auxiliary port interface: TXD_AUX and RXD_AUX
 Used for communication with the GNSS Part in all-in-one solution
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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
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Size: (18.7±0.15) × (16±0.15) × (2.1±0.2)mm
Physical Characteristics
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Weight: Approx. 1.3g
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Firmware Upgrade Firmware upgrade via UART port
Antenna Interface Connected to antenna pad with 50 Ohm impedance control
NOTES
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2.
1)
2)
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Within operation temperature range, the module is 3GPP compliant.
Within extended temperature range, the module remains the ability to establish and maintain a
voice, SMS, data transmission, emergency call, etc. There is no unrecoverable malfunction. There
are also no effects on radio spectrum and no harm to radio network. Only one or more parameters like
Pout might reduce in their value and exceed the specified tolerances. When the temperature returns to
the normal operating temperature levels, the module will meet 3GPP compliant again.

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
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Table 3: Key Features (GNSS Part of MC20)
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Features Implementation
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GNSS  GPS+BeiDou
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Power Supply  Supply voltage: 2.8V~4.3V Typical: 3.3V
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 Acquisition: 25mA @-130dBm (GPS)
 Tracking: 19mA @-130dBm (GPS)
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 Acquisition: 23mA @-130dBm (GPS+BeiDou)
Power Consumption
 Tracking: 18mA @-130dBm (GPS+BeiDou)
 Standby: 300uA @VCC=3.3V
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 Backup: 14uA @V_BCKP=3.3V
 GPS L1 1575.42MHz C/A Code
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Receiver Type
 BeiDou B1 1561.098MHz C/A Code
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 Acquisition: -148dBm
Sensitivity
 Reacquisition: -160dBm
GPS+BeiDou
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 Tracking: -163dBm
 Cold Start: <15s average @-130dBm
Time-to-First-Fix
 Warm Start: <5s average @-130dBm
(EASY Enabled) 1)
 Hot Start: 1s @-130dBm
 Cold Start (Autonomous): <35s average @-130dBm
Time-to-First-Fix
 Warm Start (Autonomous): <30s average @-130dBm
(EASY Disabled)
 Hot Start (Autonomous): 1s @-130dBm
Horizontal Position
 <2.5 m CEP @-130dBm
Accuracy (Autonomous)
Update Rate  Up to 10Hz, 1Hz by default
Velocity Accuracy  Without aid: 0.1m/s
Acceleration Accuracy  Without aid: 0.1m/s²

 Maximum Altitude: 18,000m

Dynamic Performance  Maximum Velocity: 515m/s
 Acceleration: 4G
 GNSS UART port: GNSS_TXD and GNSS_ RXD
 Support baud rate from 4800bps to 115200bps; 115200bps by
GNSS UART Port default
 Used for communication with the GSM Part in all-in-one solution
 Used for communication with peripherals in stand-alone solution
NOTE
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1)
In this mode, GNSS part’s backup domain should be valid.
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Table 4: Protocols Supported by the Module
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Protocol Type
u n
NMEA output, ASCII, 0183, 3.01
Q ide
PMTK Input/output, MTK proprietary protocol
f
NOTE
n
Please refer to document [2] for details of NMEA standard protocol and MTK proprietary protocol.


Co
2.3. Functional Diagram
The following figure shows a block diagram of MC20 and illustrates the major functional parts.
Radio frequency part

Power management
 Peripheral interfaces
—Power supply
—Turn-on/off interface
—UART interface
—Audio interface
—SIM interface
—ADC interface
—RF interface

—PCM interface
—BT interface
—SD interface
RF_ANT
ESD RF
RF PA 26MHz
Transceiver
VBAT
l
PWRKEY
e
PMU
t
VDD_EXT VDD_EXT
c l
BT_ANT BT MEMORY Serial
a
Interface UART Port
e i
SIM1 SIM1
Interface Interface SD
SD Interface
t
Interface
SIM2 SIM2
u
Interface Interface BB
AUDIO AUDIO
n
NETLIGHT PWM
PCM PCM
Q ide
GNSS_VCC_EN
ADC ADC
MEMORY
GNSS_VCC GNSS
f
Backup Serial
GNSS UART
Domain Interface
RF Part
o n
GNSS_ANT 26MHz
LNA SAW
TCXO
C
Figure 1: Module Functional Diagram
2.4. Evaluation Board
In order to help you develop applications with MC20, Quectel supplies an evaluation board (EVB), TE-A
board, RS-232 to USB cable, power adapter, earphone, GSM antenna, GNSS antenna and other
peripherals to control or test the module. For details, please refer to document [11].

3 Application Functions
MC20 is an SMD type module with 54 LCC pads and 14 LGA pads. The following chapters provide
detailed descriptions about these pins.
 Pin of module
l
 Power supply
 Operating modes
t e
 Power on/down
l
 Power saving
c
 Backup domain of GNSS
a

e
Serial interfaces
i

t
Audio interfaces
u
 SIM card interface
n
 ADC

Q ide
Behaviors of the RI
 Network status indication
 RF transmitting signal indication
 EASY autonomous AGPS technology
f
 EPO offline AGPS technology
 Multi-tone AIC
o n
C
3.1. Pin of Module
3.1.1. Pin Assignment
LOUDSPKN
RESERVED
LOUDSPKP
NETLIGHT
VDD_EXT
VRTC
VBAT
VBAT
GND
GND
GND
GND
54 53 52 51 50 49 48 47 46 45 44 43
l
MICP 1 42 GND
RESERVED
RESERVED
RESERVED
MICN 2 41 RF_ANT
e
SPKP 3 40 GND
t
SPKN 4 39 RTS
l
PWRKEY 5 68 67 66 38 CTS
c
ADC 6 RESERVED 55 65 RESERVED 37 DTR
a
SD_CMD 7 36 DCD
e i
RESERVED 56 64 RESERVED
MC20
SD_CLK 8 35 RI
t
RESERVED 57 Top view 63 RESERVED
u
SD_DATA 9 34 TXD
SIM2_CLK 10 33 RXD
n
RESERVED 58 62 PCM_IN
SIM2_DATA 11 59 60 61 32 BT_ANT
Q ide
SIM2_RST 12 31 GND
PCM_SYNC
PCM_OUT
PCM_CLK
SIM2_VDD 13 30 DBG_RXD
GND 14 29 DBG_TXD
GNSS_ANT 15 28 GNSS_VCC_EN
n f 16 17 18 19 20 21 22 23 24 25 26 27
o
GNSS_TXD
RESERVED
GND
SIM_GND
GNSS_VCC
GNSS_RXD
SIM1_VDD
TXD_AUX
SIM1_RST
SIM1_CLK
RXD_AUX
SIM1_DATA
C
VBAT SIM1 GND RF UART
Power SIM2 RESERVED AUDIO OTHER
Figure 2: Pin Assignment
NOTE
Please keep all reserved pins open.

3.1.2. Pin Description
Table 5: I/O Parameters Definition
Type Description
IO Bidirectional input/output
DI Digital input
DO Digital output
l
PI Power input
e
PO Power output
t l
AI Analog input
c a
AO Analog output
u e
Table 6: Pin Description
n t i
Q ide
Power Supply
PIN Name PIN No. I/O Description DC Characteristics Comment
f
It must be able to
Power supply of VImax=4.6V provide sufficient
n
VBAT 50, 51 PI GSM/GPRS part: VImin=3.3V current up to 1.6A
o
VBAT=3.3V~4.6V VInorm=4.0V in a transmitting
burst.
C
Power supply of GNSS VImax=4.3V Assure load
GNSS_
26 PI part: VImin=2.8V current no less
VCC
GNSS_VCC=2.8V~4.3V VInorm=3.3V than 150mA.
Keep this pin
VRTC 52 IO
open
1. If unused, keep
this pin open.
VOmax=2.9V 2. Recommend
VDD_ Supply 2.8V voltage for VOmin=2.7V adding a
43 PO
EXT external circuit. VOnorm=2.8V 2.2~4.7uF bypass
IOmax=20mA capacitor, when
using this pin for
power supply.
GND 14,27, Ground

31,40,
42,44,
45,48,
49
Turn on/off

Power on/off key. VILmax=
PWRKEY should be 0.1×VBAT
PWRKEY 5 DI pulled down for a VIHmin=
moment to turn on or 0.6×VBAT
l
turn off the system. VIHmax=3.1V
e
Audio Interface
t l
c
MICP 1, Positive and negative If unused, keep
a
AI
e i
MICN 2 voice input these pins open.
t
If unused, keep
u
these pins open.
n
SPKP 3, Channel 1 positive and
AO Support both
SPKN 4 negative voice output
Q ide
voice and
ringtone output.
1. If unused, keep
Refer to Chapter 3.7.6
f
these pins open.
2. Integrate a
LOUD
n
Class- AB
SPKP 54 Channel 2 positive and
AO amplifier
o
LOUD 53 negative voice output
internally.
SPKN
3. Support both
C
voice and
ringtone output.
Network Status Indicator

VOHmin=
Network status 0.85×VDD_EXT If unused, keep
NETLIGHT 47 DO
indication VOLmax= this pin open.
0.15×VDD_EXT
UART Port
TXD 34 DO Transmit data VILmin=0V If only TXD, RXD

RXD 33 DI Receive data VILmax= and GND are

0.25×VDD_EXT used for
DTR 37 DI Data terminal ready VIHmin= communication, it
RI 35 DO Ring indication 0.75×VDD_EXT is recommended
VIHmax= to keep all other
DCD 36 DO Data carrier detection VDD_EXT+0.2 pins open.
VOHmin=
CTS 38 DO Clear to send
0.85×VDD_EXT
VOLmax=
RTS 39 DI Request to send
0.15×VDD_EXT
Debug Port
l
t e
DBG_
29 DO Transmit data
l
TXD The same as UART If unused, keep
c
DBG_ port these pins open.
a
30 DI Receive data
e
RXD
t i
Auxiliary UART Port
u n
Q ide
TXD_
25 DO Transmit data
AUX The same as UART Refer to Chapter
RXD_ port 3.6.3
24 DI Receive data
f
AUX
GNSS UART Port
n
o
GNSS_ VOLmax=0.42V
22 DO Transmit data
TXD VOHmin=2.4V
C
VOHnom=2.8V
Refer to Chapter
VILmin=-0.3V
GNSS_ 3.6.3
23 DI Receive data VILmax=0.7V
RXD
VIHmin=2.1V
VIHmax=3.1V
SIM Interface

The voltage can be All signals of SIM
SIM1_ VDD 18 Power supply for SIM selected by software interface should
PO
SIM2_ VDD 13 card automatically. Either be protected
1.8V or 3.0V. against ESD with
SIM1_ CLK 19 VOLmax= a TVS diode
DO SIM clock
SIM2_ CLK 10 0.15×SIM_VDD array.

VOHmin= Maximum trace

0.85×SIM_VDD length is 200mm
VILmax= from the module
SIM1_ 0.25×SIM_VDD pad to SIM card
VIHmin=
DATA holder.
21 0.75×SIM_VDD
SIM2_ IO SIM data VOLmax=
11
DATA 0.15×SIM_VDD
VOHmin=
0.85×SIM_VDD
VOLmax=
SIM1_ RST 20 0.15×SIM_VDD
DO SIM reset
l
SIM2_ RST 12 VOHmin=
0.85×SIM_VDD
t e
SIM_
16 SIM ground
l
GND
c
VILmin =0V
e a
VILmax =
t i
0.25×VDD_EXT
SIM1_
u
37 I SIM1 card detection VIHmin =
PRESENCE
n
0.75×VDD_EXT
Q ide
VIHmax =
VDD_EXT+0.2
ADC
f
n
General purpose
Voltage range: If unused, keep
ADC 6 AI analog to digital
o
0V to 2.8V this pin open.
converter.
Digital Audio Interface (PCM)
C
PCM_CLK 59 DO PCM clock
PCM_OUT 60 DO PCM data output

If unused, keep
PCM frame these pins open
PCM_SYNC 61 DO
synchronization
PCM_IN 62 DI PCM data input
SD Card Interface
SD_CMD 7 DO SD Command line

If unused, keep
SD_CLK 8 DO SD clock
these pins open
SD_DATA 9 IO SD data line

Antenna Interface

RF_
41 IO GSM antenna pad Impedance of 50Ω
ANT
BT_ If unused, keep
32 IO BT antenna pad Impedance of 50Ω
ANT this pin open.
GNSS_
15 I GNSS signal input Impedance of 50Ω
ANT
Other Interface
l
e
Refer to
t
Chapter 3.3.3.2
l
VOHmin=
c
in all-in-one
GNSS_ 0.85×VDD_EXT solution.
a
28 O GNSS power enabled
e i
VCC_EN VOLmax= Keep this pin
t
0.15×VDD_EXT open in
u
stand-alone
n
solution.
Q ide
17, 46
55, 56,
57, 58, Keep these pins
RESERVED
f
63, 64, open
65, 66,
n
67, 68,
Co
Table 7: Multiplexed Functions
PIN Name PIN No. Function After Reset Alternate Function
DTR/SIM1_PRESENCE 37 DTR SIM1_PRESENCE
3.2. Application Modes Introduction
MC20 module integrates both GSM and GNSS engines which can work as a whole (all-in-one solution)
unit or work relatively independent (stand-alone solution) according to customer demands.
All-in-one solution allows for convenient communication between GSM and GNSS parts. The commands
and data (e.g. AT and PMTK commands, NMEA sentences output, etc.) in both GSM and GNSS parts are

transmitted through UART port, thus realizing communication between the module and the MCU.
In stand-alone solution, GSM data and AT commands are transmitted through UART port; while GNSS
data such as PMTK command and NMEA sentences output are transmitted through GNSS UART port.
The hardware difference between all-in-one solution and stand-alone solution mainly lies in the
connection method of UART, UART_AUX, and GNSS_UART. The corresponding schematic diagrams are
shown below.
DC 5V
l
VBAT
LDO VBAT
e
PWRKEY PWRKEY
t
MC20
Module
c l
IN UART_AUX
EN GNSS_VCC_EN
e a
LDO
i
GNSS_UART
t
OUT GNSS_VCC
u
UART PORT
Q ide n
MCU
f
Figure 3: All-in-one Solution Schematic Diagram
o n
DC 5V
C
VBAT
LDO VBAT
PWRKEY PWRKEY
MC20
Module
IN
EN GNSS_VCC_EN
LDO
OUT GNSS_VCC
UART PORT GNSS_UART
MCU
Figure 4: Stand-alone Solution Schematic Diagram

NOTE
In order to ensure the normal operation of GNSS part, please don't power off the GSM part.
Table 8: Comparison between All-in-one and Stand-alone Solution
All-in-one. Stand-alone Remarks
Firmware upgrade via Firmware upgrade via

UART Port (GSM and UART Port (GSM and Refer to Chapter
l
Firmware upgrade
GNSS Parts share the GNSS Parts share the 3.6.1.3 for details
e
same firmware package) same firmware package)
t
GSM data is transmitted
c l
through the GSM UART
Both GSM and GNSS data
Port.
a
Data transmission are transmitted through
e i
GNSS data is transmitted
the GSM UART Port
t
through the GNSS UART
u
Port.
n
GNSS can wake up GSM
Q ide
GNSS wake up GSM N/A
by interrupts
MCU receives the EPO
EPO data is downloaded data which is downloaded
GNSS’s EPO data Refer to Chapter
f
directly through the GSM through the GSM part, and
download 3.13 for details
part. then transmit it to the
n
GNSS part.
C
3.3. Power Supply
o
3.3.1. Power Features
The power supply of the GSM part is one of the key issues in MC20 module design. Due to the 577us
radio burst in GSM part every 4.615ms, the 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 the minimum working
voltage of the GSM part.
The maximum current consumption of GSM part could reach 1.6A during a burst transmission. It will
cause a large voltage drop on the VBAT. In order to ensure stable operation of the part, it is
recommended that the maximum voltage drop during the burst transmission does not exceed 400mV.

4.615ms
577us
Burst:1.6A
IBAT
VBAT
Vdrop
l
Figure 5: Voltage Ripple during Transmitting (GSM Part)
t e
The power supply for GNSS part is controlled by the GSM part through AT command control over
l
GNSS_VCC_EN pin.
e c ia
3.3.2. Decrease Supply Voltage Drop
t
u n
3.3.2.1. Decrease Supply Voltage Drop for GSM Part
Q ide
Power supply range of the GSM part is from 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 will be turned
f
off automatically. For better power performance, it is recommended to place a 100uF tantalum capacitor
with low ESR (ESR=0.7Ω) and ceramic capacitors 100nF, 33pF and 10pF near the VBAT pin. A reference
n
circuit is illustrated in the following figure.
o
The VBAT trace 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 in principle, the longer the VBAT trace,
C
the wider it will be.

VBAT
+ C1 C2 C3 C4
100uF 100nF 10pF 33pF

0603 0603
t el GND
c a l
Figure 6: Reference Circuit for the VBAT Input (GSM Part)
u e n t i
3.3.2.2. Decrease Supply Voltage Drop for GNSS Part
Q ide
Power supply range of GNSS part is from 2.8 to 4.3V. GNSS_VCC’s maximum average current is 40mA
during GNSS acquisition after power up. So it is important to supply sufficient current and make the power
clean and stable. The decouple combination of 10uF and 100nF capacitor is recommended nearby
f
GNSS_VCC pin. A reference circuit is illustrated in the following figure.
n
GNSS_VCC
Co C1
10uF
C2
100nF
GND
Figure 7: Reference Circuit for the GNSS_VCC Input

3.3.3. Reference Design for Power Supply
3.3.3.1. Reference Design for Power Supply of GSM Part
The power supply of GSM part is capable of providing 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 the GSM part’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 the power supply.
The following figure shows a reference design for +5V input power source for GSM part. The designed
l
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
e
suggested to use a zener diode whose reverse zener voltage is 5.1V and dissipation power is more than 1
t
Watt.
c a l
MIC29302WU U1
e t i
DC_IN VBAT
u
2 IN OUT 4
n
R2
GND
124K
Q ide
ADJ
EN
1
C1 C2 R4 C3 C4 D1
R1
51K
470uF R3 5.1V
100nF 470R 470uF 100nF
56K
f
R5
4.7K
n
MCU_POWER_ON/OFF
R6
o
47K
C
Figure 8: Reference Circuit for Power Supply of the GSM Part
NOTE
It is suggested to control the module’s main power supply (VBAT) via LDO enable pin to restart the
module when the module becomes abnormal. Power switch circuit like P-channel MOSFET switch circuit
can also be used to control VBAT.

3.3.3.2. Reference Design for Power Supply of GNSS Part
The power supply for GNSS part is controlled by the GSM part through AT command control over
GNSS_VCC_EN pin.
A reference circuit for the GNSS part power supply is given below. Please pay attention to the electrical
characteristics of GNSS_VCC_EN to match LDO’s EN pin. Please refer to document [1] for details about
the AT commands for GNSS control.
U1
U2
l
VBAT
1 5 26
VIN VOUT GNSS_VCC
e
R1
t
2 GND
l
C1 75K 1% C2 C3
c
3 FB 4 MC20
EN
1uF 4.7uF 100nF Module
a
R2
e i
SGM2019-ADJYN5G/TR 43K 1%
u n t
28
GNSS_VCC_EN
Q ide
R3
47K
f
Figure 9: Reference Circuit Design for GNSS Part
o n
3.3.4. Monitor Power Supply
C
The command AT+CBC can be used to monitor the supply voltage of the GSM part. The unit of the
displayed voltage is mV.
For details, please refer to document [1].
3.3.5. Backup Domain of GNSS
The GNSS part of MC20 module features a backup domain which contains all the necessary GNSS
information for quick start-up and a small amount of user configuration variables. In GNSS’s backup mode,
the backup domain is still alive. As long as the backup domain is alive, EASY technology will be available.
As the GNSS’s backup domain is powered by VBAT, the GNSS’s backup mode will be active as long as
the following conditions are satisfied at the same time:

 The main power supply (VBAT) is remained

 The GSM part is powered on
 The GNSS part is turned off by AT+QGNSSC=0 command via UART
In this case, the VRTC pin can be kept floating. A reference schematic diagram is shown below.
MC20 Module
GSM Part GNSS Part

VBAT
l
RTC Backup
LDO
Core Domain
t e
VRTC
e c ia l
Figure 10: Internal GNSS’s Backup Domain Power Construction
u n t
Q ide
3.4. Operating Modes
3.4.1. Operating Modes of GSM Part
f
The table below briefly summarizes the various operating modes of GSM part mentioned in the following
n
chapters.
o
Table 9: Operating Modes Overview of GSM Part
C
Modes Function
After enabling sleep mode by AT+QSCLK=1, the GSM part will

automatically enter into Sleep Mode if DTR is set to high level
and there is no interrupt (such as GPIO interrupt or data on
GSM/GPRS
UART port). In this case, the current consumption of the GSM
Sleep
part will reduce to the minimal level.
GSM Normal During Sleep Mode, the GSM part can still receive paging
Operation message and SMS from the system normally.
Software is active. The GSM part has registered on GSM
GSM IDLE
network, and it is ready to send and receive GSM data.
GSM connection is ongoing. In this mode, the power
GSM TALK consumption is decided by the configuration of Power Control
Level (PCL), dynamic DTX control and the working RF band.

The GSM part is not registered on GPRS network. It is not

GPRS IDLE
reachable through GPRS channel.
The GSM part is registered on GPRS network, but no GPRS
GPRS
PDP context is active. The SGSN knows the Routing Area
STANDBY
where the module is located at.
The PDP context is active, but no data transfer is ongoing. The
GPRS READY GSM part 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.
l
Normal shutdown by sending the AT+QPOWD=1 command or using the
e
PWRKEY pin. The power management ASIC disconnects the power supply from
POWER DOWN
t
the base band part of the GSM part. Software is not active. The UART interfaces
l
are not accessible. Operating voltage (connected to VBAT) remains applied.
c
AT+CFUN command can set the GSM part to a minimum functionality mode
a
Minimum
e i
without removing the power supply. In this case, the RF part of the GSM part will
Functionality Mode
t
not work or the SIM card will not be accessible, or both RF part and SIM card will
u
(without removing
be disabled; but the UART port is still accessible. The power consumption in this
n
power supply)
case is very low.
Q ide
Based on system requirements, there are several actions to drive the GSM part to enter into low current
consumption status. For example, AT+CFUN can be used to set the part into minimum functionality mode,
and DTR hardware interface signal can be used to lead the system to Sleep Mode.
n f
3.4.1.1. Minimum Functionality Mode
o
Minimum functionality mode reduces the functionality of the GSM part to a minimum level. The
C
consumption of the current can be minimized when the slow clocking mode is activated at the same time.
The mode is set via 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 from both transmitting and receiving RF signals
If the GSM part 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 unavailable.
If the GSM part is set by the command 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 unavailable.

After the GSM part is set by AT+CFUN=0 or AT+CFUN=4, it can return to full functionality mode by
AT+CFUN=1.
For detailed information about AT+CFUN, please refer to document [1].
3.4.1.2. SLEEP Mode
SLEEP mode is disabled by default. It can be enabled by AT+QSCLK=1 and the premise is that the
GNSS is powered off. The default setting is AT+QSCLK=0, and in this mode, the GSM part cannot enter
l
SLEEP mode.
t e
When the GSM part is set by the command AT+QSCLK=1, you can control the part to enter into or exit
l
from the SLEEP mode through pin DTR. When DTR is set to high level, and there is no on-air or hardware
c
interrupt such as GPIO interrupt or data on UART port, the GSM part will enter into SLEEP mode
e a
automatically. In this mode, the GSM part can still receive voice, SMS or GPRS paging from network, but
t i
the UART port does not work.
u
Q ide n
3.4.1.3. Wake up GSM Part from SLEEP Mode
When the GSM part is in the SLEEP mode, it can be woken up through the following methods:
f
 If the DTR Pin is set low, it would wake up the GSM part from the SLEEP mode. The UART port will
n
be active within 20ms after DTR is changed to low level.
 Receiving a voice or data call from network wakes up the GSM part.
o
 Receiving an SMS from network wakes up the GSM part.
C
NOTE
DTR pin should be held at low level during communication between the GSM part and the DTE.
3.4.2. Operating Modes of GNSS Part
3.4.2.1. Full on Mode
Full on mode includes tracking mode and acquisition mode. Acquisition mode is defined as that the GNSS
part starts to search satellites, and to determine the visible satellites, coarse carrier frequency & code
phase of satellite signals. When the acquisition is completed, it switches to tracking mode automatically.
Tracking mode is defined as that the GNSS part tracks satellites and demodulates the navigation data

from specific satellites.
When the GNSS_VCC is valid, the GNSS part will enter into full on mode automatically. The following
table describes the default configuration of full on mode.
Table 10: Default Configuration of Full on Mode (GNSS Part)
Item Configuration Comment
Baud Rate 115200bps
l
Protocol NMEA RMC, VTG, GGA, GSA, GSV and GLL
e
Update Rate 1Hz
c t l
SBAS Enable
e ia
AIC Enable
u t
LOCUS Disable
n
EASY will be disabled automatically when update
Easy Technology Enable
Q ide
rate exceeds 1Hz.
GNSS GPS+BeiDou
f
In full on mode, the consumption complies with the following regulations:
n
When the GNSS part is powered on, the average current will rush to 40mA and last for a few seconds;
o
then the consumption will be decreased to the acquisition current marked in table 3 and we defined this
state as acquisition state, and also it will last for several minutes until it switches to tracking state
C
automatically. The consumption in tracking state is less than that in acquisition state. The value is also
listed in table 3.
Sending PMTK commands allows for switching among multiple positioning systems:
 $PMTK353,0,0,0,0,1*2A: search BDS satellites only
 $PMTK353,1,0,0,0,0*2A: search GPS satellites only
 $PMTK353,1,0,0,0,1*2B: search GPS and BDS satellites
NOTE
In all-in-one solution, make sure the GNSS part is powered on before sending these PMTK commands.

3.4.2.2. Standby Mode
Standby mode is a low-power consumption mode. In standby mode, the internal core and I/O power
domain are still active; but RF and TCXO are powered off, and the GNSS part stops satellites search and
navigation. The way to enter into standby mode is using PMTK commands.
When the GNSS part exits from standby mode, it will use all internal aiding information like GNSS time,
ephemeris, last position, etc., to ensure the fastest possible TTFF in either Hot or Warm start. The typical
current consumption is about 300uA @GNSS_VCC=3.3V in standby mode.
Sending the following PMTK command can make GNSS part enter into standby mode:
l
 $PMTK161,0*28: make sure the GNSS part is powered on before sending the command in
e
all-in-one solution.
t l
The following methods will make GNSS part exit from standby mode:
c
 Sending any data via UART will make GNSS part exit from standby mode in all-in-one solution.
e a
 Sending any data via GNSS_UART will make GNSS part exit from standby mode in stand-alone
t i
solution.
u
Q ide
3.4.2.3. Backup Mode
n
Backup mode requires lower power consumption than standby mode. In this mode, the GNSS part stops
f
acquiring and tracking satellites, but the backed-up memory in backup domain which contains all the
necessary GNSS information for quick start-up and a small amount of user configuration variables is alive.
n
As long as the backup domain is alive, EASY technology is available. The current consumption in this
mode is about 14uA.
o
The following method will make GNSS part enter into backup mode:
C
 When VBAT is kept powered and the GSM part is powered on, sending AT+QGNSSC=0 will make
GNSS part enter into backup mode from full on mode.
The following method will make GNSS part exit from backup mode:
 Sending AT+QGNSSC=1 via UART, the GNSS part will exit from backup mode and enter full on
mode immediately.
NOTE
In order to enable GNSS part working in backup mode, please make sure the GSM part is powered on.

3.4.3. Summary of GSM and GNSS Parts’ State in All-in-one Solution
Table 11: Combination States of GSM and GNSS Parts in All-in-one Solution
GSM Part Modes GNSS Part Modes
Full on Standby Backup
Normal   
Sleep   
l
Minimum Functionality   
t e l
3.4.4. Summary of GSM and GNSS Parts’ State in Stand-alone Solution
e c ia
Table 12: Combination States of GSM and GNSS Parts in Stand-alone Solution
u t
GSM Part Modes GNSS Part Modes
Q ide n
Full on Standby Backup
Normal   
f
Sleep   
n
Minimum Functionality   
o
NOTES
C
1. The mark  means that the Part supports this mode.
2. In all-in-one solution, all PMTK commands used for the GNSS part should be sent through the GSM
UART after the GNSS part is powered on. Make sure the GSM UART Port is accessible.
3. In all-in-one solution, when the GSM part is in sleep mode, the GNSS part can work in either standby
or full on mode. However, if NMEA GPS data is needed, the GSM part should be woken up first and
then send the corresponding AT command to get. For detailed AT command information, please refer
to document [1].
4. In stand-alone solution, all PMTK commands used for the GNSS part or NMEA output can be sent or
received through GNSS UART port when the GSM part is powered on.

3.5. Power on and down
3.5.1. 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.
PWRKEY
l
4.7K
t e
Turn on pulse
e c a l
47K
u n t i
Q ide
Figure 11: Turn on the Module with an Open-collector Driver
NOTES
f
1. MC20 module is set to autobauding mode (AT+IPR=0) by default. In autobauding mode, URC RDY is
n
not reported to the host controller after the module is powered on. When the module is powered on after
o
a delay of 4 or 5 seconds, it can receive AT commands. Host controller should first send an AT string in
order that the module can detect baud rate of host controller, and 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
C
the module and save the configuration to flash memory of the module. After these configurations, the
URC RDY would be received from the UART Port of the module every time when the module is
powered on. For more details, refer to the section AT+IPR in document [1].
2. When AT command is responded, it indicates the module is turned on successfully; or else the module
fails to be turned on.
The other way to control the PWRKEY is through a button directly. While pressing the key, electrostatic
strike may generate from the finger, and thus, 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. A reference circuit is shown in the following figure.

S1
PWRKEY
TVS
Close to
S1
l
Figure 12: Turn on the Module with a Button
t e l
Command AT+QGNSSC=1 should be sent to enable the GNSS power supply after the GSM part is
c
running. When the GNSS_VCC is valid, the GNSS will enter into full on mode automatically. The turn-on
e a
timing is illustrated in the following figure.
VBAT
u
T1
n t i
Q ide
>1s
VIH > 0.6*VBAT
f
PWRKEY
(INPUT) VIL<0.1*VBAT
n
54ms
o
VDD_EXT Send AT+QGNSSC=1
(OUTPUT) Through GSM UART
Port
C
GSM PART STATUS OFF BOOTING RUNNING
GNSS_VCC_EN
GNSS_VCC
GNSS PART STATUS OFF RUNNING
Figure 13: Turn-on Timing

NOTE
Make sure that VBAT is stable before pulling down PWRKEY pin. The time of T1 is recommended to be
100ms.
3.5.2. Power down
The following procedures can be used to turn off the module:
 Normal power down procedure: Turn off module using the PWRKEY pin
l
 Normal power down procedure: Turn off module using command AT+QPOWD
 Under-voltage automatic shutdown: Take effect when under-voltage is detected.
c t e l
3.5.2.1. Power down Module Using the PWRKEY Pin
e t ia
It is a safe way to turn off the module by driving the PWRKEY to a low level voltage for a certain time. The
u
power down scenario is illustrated in the following figure.
Q ide n
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.
Before the completion of the power down procedure, the module sends out the result code shown below:
f
NORMAL POWER DOWN
NOTES
o n
C
1. When unsolicited result codes do not appear when autobauding is active and DTE & DCE are not
correctly synchronized after start-up, the module is recommended to be set to a fixed baud rate.
2. As network logout 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.
After that moment, no further AT commands can be executed. Then the module enters the power down
mode.

VBAT
0.7s<Pulldown<1s
Logout from network in 2-12s
PWRKEY
(INPUT)
VDD_EXT
(OUTPUT)
l
GNSS_VCC_EN
t e
GNSS_VCC
e c ia l
t
GSM PART STATUS RUNNING OFF
u
Q ide n
GNSS PART STATUS RUNNING OFF
f
Figure 14: Turn-off Timing by Using the PWRKEY Pin
o n
3.5.2.2. Power down Module Using AT Command
C
It is also a safe way to turn off the module via AT command AT+QPOWD=1. This command will let the
module 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 out the result code shown below:
NORMAL POWER DOWN
After that moment, no further AT commands can be executed. And then the module enters into the power
down mode.
Please refer to document [1] for details about the AT command AT+QPOWD.

3.5.2.3. Power down GNSS Part Alone Using AT Command
It is a safe way to turn off the GNSS part alone via AT command AT+QGNSSC=0. The power down
scenario for GNSS part is illustrated in the following figure.
VBAT
Send AT+QGNSSC=0
Through GSM UART Port
GSM PART STATUS
RUNNING
el
VDD_EXT
(OUTPUT)
c t a l
e i
GNSS_VCC_EN
u n t
GNSS_VCC
Q ide
f
GNSS PART STATUS RUNNING OFF
o n
Figure 15: Turn-off Timing of GNSS Part by Using AT Command
C
3.5.2.4. 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
The normal input voltage range is from 3.3V to 4.6V. If the voltage is <3.3V, the module will automatically
shut down.
If the voltage is <3.3V, the following URC will be presented:

UNDER_VOLTAGE POWER DOWN
After that moment, no further AT commands can be executed. The module logs off from network and
enters into power down mode.
NOTE
When unsolicited result codes do not appear when autobauding is active and DTE & DCE are not
correctly synchronized after start-up, the module is recommended to be set to a fixed baud rate.
l
3.6. Serial Interfaces
c t e l
The module provides four serial ports: UART Port, Debug Port, Auxiliary UART Port and GNSS UART
a
Port. The module is designed as DCE (Data Communication Equipment), following the traditional
e i
DCE-DTE (Data Terminal Equipment) connection. Autobauding function supports baud rate from
t
4800bps to 115200bps.
u n
The UART Port:
Q ide
 TXD: Send data to RXD of DTE.
 RXD: Receive data from TXD of DTE.
f
 RTS: Request to send.
 CTS: Clear to send.
n
 DTR: DTE is ready and inform DCE (this pin can wake the module up).
 RI: Ring indicator (when there is a call, SMS or URC output, the module will inform DTE with the RI
o
pin).
 DCD: Data carrier detection (the validity of this pin demonstrates successful set-up of the
C
communication link).
The Debug Port:
 DBG_TXD: Send data to the COM port of peripheral.

 DBG_RXD: Receive data from the COM port of peripheral.
The Auxiliary UART Port:
 In all-in-one solution:
TXD_AUX: Send data to the GNSS part.
RXD_AUX: Receive data from the GNSS part.
 In stand-alone solution:
TXD_AUX: Keep open except during firmware upgrade.

RXD_AUX: Keep open except during firmware upgrade.
The GNSS UART Port
 In all-in-one solution:
GNSS_TXD: Send data to the GSM part.
GNSS_RXD: Receive data from the GSM part.
 In stand-alone solution:
GNSS_TXD: Send GNSS data to the COM port of peripheral.
GNSS_RXD: Receive GNSS data from the COM port of peripheral.
l
The logic levels are described in the following table.
c t e l
Table 13: Logic Levels of the UART Interface
e ia
Parameter Min. Max. Unit
u t
VIL 0 0.25×VDD_EXT V
Q ide n
VIH 0.75×VDD_EXT VDD_EXT +0.2 V
VOL 0 0.15×VDD_EXT V
f
VOH 0.85×VDD_EXT VDD_EXT V
o n
Table 14: Pin Definition of the UART Interfaces
C
Interface Pin Name Pin No. Description
TXD 34 Transmit data
RXD 33 Receive data
DTR 37 Data terminal ready
UART Port RI 35 Ring indication
DCD 36 Data carrier detection
CTS 38 Clear to send
RTS 39 Request to send
Debug Port DBG_RXD 30 Receive data

DBG_TXD 29 Transmit data
RXD_AUX1) 24 Receive data

Auxiliary UART Port1)
TXD_AUX1) 25 Transmit data
GNSS_RXD 23 Receive data

GNSS UART Port
GNSS_TXD 22 Transmit data
NOTE
l
1)
e
It is recommended to keep these pins open in stand-alone solution, except during firmware upgrade.
3.6.1. UART Port
c t a l
u e t i
3.6.1.1. Features of UART Port
n

Q ide
Seven lines on UART interface
 Contain data lines TXD and RXD, hardware flow control lines RTS and CTS, as well as other control
lines DTR, DCD and RI.
 Used for AT command, GPRS data, etc. Multiplexing function is supported on the UART Port. NMEA
f
output and PMTK command can be supported in all-in-one solution.
 Support the following communication baud rates:
n
300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600, 115200bps.
o
 The default setting is autobauding mode. Support the following baud rates for autobauding function:
4800, 9600, 19200, 38400, 57600, 115200bps.
C
 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 document [1].
After setting a fixed baud rate or autobauding, please send ―AT‖ string at that rate. The UART port is
ready when it responds ―OK‖.
Autobauding allows the module to detect the baud rate by receiving the string ―AT‖ or ―at‖ from the host or
PC automatically, which gives module flexibility without considering which baud rate is used by the host
controller. Autobauding is enabled by default. To take advantage of the autobauding mode, special
attention should be paid according to the following requirements:

Synchronization between DTE and DCE:
When DCE (the module) is powered on with autobauding enabled, it is recommended to wait 2 to 3
seconds before sending the first AT character. After receiving the ―OK‖ response, DTE and DCE are
correctly synchronized.
If the host controller needs URC in the mode of autobauding, it must be synchronized firstly. Otherwise
the URC will be discarded.
Restrictions on autobauding operation:
l
 The UART port has to be operated at 8 data bits, no parity and 1 stop bit (factory setting).
 The ―At‖ and ―aT‖ commands cannot be used.
e
 Only the strings ―AT‖ or ―at‖ can be detected (neither ―At‖ nor ―aT‖).
t
 The Unsolicited Result Codes like RDY, +CFUN: 1 and +CPIN: READY will not be indicated when
c l
the module is turned on with autobauding enabled and not be synchronized.
a
 Any other Unsolicited Result Codes will be sent at the previous baud rate before the module detects
e i
the new baud rate by receiving the first ―AT‖ or ―at‖ string. The DTE may receive unknown characters
u t
after switching to a new baud rate.

n
It is not recommended to switch to autobauding from a fixed baud rate.
 If autobauding is active it is not recommended to switch to multiplex mode.
NOTE
Q ide
f
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
n
autobauding after start-up. For more details, please refer to the Section AT+IPR in document [1].
Co
3.6.1.2. The Connection of UART
The connection between module and host using UART Port is very flexible. Three connection styles are
illustrated as below.
A reference design for Full-Function UART connection is shown as below when it is applied in
modulation-demodulation.

Module (DCE) Host (DTE)

UART port Controller
TXD TXD
RXD RXD
RTS RTS
CTS CTS
DTR DTR
DCD DCD
RI RING
GND GND
l
Figure 16: Reference Design for Full-Function UART
t e l
Three-line connection is shown as below.
e c
Module (DCE)
t ia
Host (DTE)
u
UART port Controller
Q ide n
TXD TXD
RXD RXD
f
GND GND
o n
C
Figure 17: Reference Design for UART Port (Three Line Connection)
A reference design for UART Port with hardware flow control is shown as below. The connection will
enhance the reliability of the mass data communication.

Module (DCE) Host (DTE)

Controller
TXD TXD
RXD RXD
RTS RTS
CTS CTS
GND GND
t el
Figure 18: Reference Design for UART Port with Hardware Flow Control
e c ia l
t
3.6.1.3. Firmware Upgrade
u n
TXD and RXD can be used for firmware upgrade in both all-in-one solution and stand-alone solution.
Q ide
The PWRKEY pin must be pulled down before firmware upgrade. A reference circuit is shown as below:
Host (DTE)
Module (DCE)
Controller
f
UART port
GNSS_TXD TXD TXD
n
GNSS_RXD
R2 R1 RXD RXD
o
0R 0R GND GND
C
RXD_AUX
PWRKEY PWRKEY
TXD_AUX
Figure 19: Reference Design for Firmware Upgrade
NOTES
1. In stand-alone solution, make sure the Auxiliary UART Port is connected to the GNSS UART Port
during firmware upgrade. Please refer to Chapter 3.6.3.2 for details.
2. The firmware of module might need to be upgraded due to a certain reasons. It is thus recommended
to reserve these pins in the host board for firmware upgrade.

3.6.2. Debug Port
 Two lines: DBG_TXD and DBG_RXD.

 The port outputs log information automatically.
 Debug Port is only used for firmware debugging and its baud rate must be configured as 460800bps.
Module Peripheral
DBG_TXD TXD
l
DBG_RXD RXD
c t e GND
l
GND
u e t ia
n
Figure 20: Reference Design for Debug Port
Q ide
3.6.3. Auxiliary UART Port and GNSS UART Port
f
3.6.3.1. Connection in All-in-one Solution
o n
In all-in-one solution, the Auxiliary UART Port and GNSS UART Port should be connected together, thus
allowing for communication between GSM and GNSS parts. A reference design is shown below.
C
GNSS_TXD
GNSS_RXD
R2 R1
MC20 Module
0R 0R
RXD_AUX
l
TXD_AUX
c t e l
e ia
Figure 21: Auxiliary and GNSS UART Port Connection in All-in-one Solution
u n t
NOTE
Q ide
As the GNSS part of MC20 module outputs more data than a single GNSS system, the default output
NMEA types running in 4800bps baud rate and 1Hz update rate will lose some data. The solution to avoid
losing data in 4800bps baud rate and 1Hz update rate is to decrease the output NMEA types. 115200bps
f
baud rate is enough to transmit GNSS NMEA in default settings and it is thus recommended.
o n
3.6.3.2. Connection in Stand-alone Solution
C
In stand-alone solution, the GNSS UART Port is connected to the COM port of peripheral. During
firmware upgrade, switch S1 should be kept closed. Otherwise, it should be kept open. A reference design
is shown below.

MC20 Peripheral
Module
GNSS_TXD TXD
GNSS_RXD RXD
S1
RXD_AUX
l
TXD_AUX
c t e l
Figure 22: Auxiliary and GNSS UART Port Connection in Stand-alone Solution
e t ia
3.6.4. UART Application
u n
A reference design of 3.3V level match is shown as below. If the host is a 3V system, please change the
Q ide
5.6K resistors to 10K ones.
Peripheral Module
1K
RXD
f
/TXD
1K
/RXD TXD
1K
n
/RTS RTS
1K
/CTS CTS
o
1K
GPIO DTR
1K
EINT RI
C
1K
GPIO DCD
GND GND
5.6K 5.6K 5.6K
Voltage level:3.3V
Figure 23: Level Match Design for 3.3V System
NOTE
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 a 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 [13].

The following figure shows a sketch map between the module and the standard RS-232 interface. As the
electrical level of module is 2.8V, a RS-232 level shifter must be used. Note that you should assure the
I/O voltage of level shifter which connects to module is 2.8V.
C1+ V+ GND
C1- GND GND
C2+ VCC 3.3V

Module
C2- V- GND
1K
DCD T1IN T2OUT
l
1K
TXD T2IN T1OUT
1K
e
CTS T3IN T5OUT
1K
t
RI T4IN T3OUT
1
l
T5IN T4OUT 6
c
2
5.6K /R1OUT 7
3
a
1K
RXD
e
R1OUT R1IN 8
i
1K 4
DTR
t
R2OUT R2IN 9
1K 5
u
RTS R3OUT R3IN
n
GND GND
5.6K 5.6K
Q ide
RS-232 Level Shifter
To PC Serial Port
f
Figure 24: Sketch Map for RS-232 Interface Match
o n
Please visit vendors’ websites to select a suitable IC, such as: http://www.maximintegrated.com and
http://www.exar.com/.
C
3.7. Audio Interfaces
The module provides one analog input channel and two analog output channels.
Table 15: Pin Definition of Audio Interface
Interface Pin Name Pin No. Description
MICP 1 Microphone positive input

AIN/AOUT1
MICN 2 Microphone negative input

SPKP 3 Channel 1 Audio positive output
SPKN 4 Channel 1 Audio negative output
MICP 1 Microphone positive input
MICN 2 Microphone negative input

AIN/AOUT2
LOUDSPKP 54 Channel 2 Audio positive output
LOUDSPKN 53 Channel 2 Audio negative output
l
AIN can be used for input of microphone and line. An electret microphone is usually used. AIN are
differential input channels.
t e
AOUT1 is used for output of receiver. The channel is typically used for building a receiver into a handset.
c l
AOUT1 channel is a differential channel.
e ia
AOUT2 is used for loudspeaker output as it is embedded with an amplifier of class AB whose maximum
t
drive power is 800mW. AOUT2 is a differential channel.
u n
AOUT2 also can be used for output of earphone, and can be used as a single-ended channel.
Q ide
All these audio channels support voice and ringtone output, and so on, and can be switched by
AT+QAUDCH command. For more details, please refer to document [1].
f
Use AT command AT+QAUDCH to select audio channel:
n
 0--AIN/AOUT1, the default value is 0.
o
 1--AIN/AOUT2, this channel is always used for earphone.
 2--AIN/AOUT2, this channel is always used for loudspeaker.
C
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 document [1].
Table 16: AOUT2 Output Characteristics
Item Condition Min. Typ. Max. Unit
8ohm load
RMS Power VBAT=3.7v 800 mW
THD+N=1%

3.7.1. Decrease TDD Noise and Other Noises
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 used for filtering out 1800MHz RF interference. However, the resonant frequency point of a
capacitor largely depends on the material and production technique. Therefore, customers would have to
discuss with their capacitor vendors 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
l
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.
t e l
The capacitor which is used for filtering out RF noise should be close to the audio interface. Audio
c
alignment should be as short as possible.
e ia
In order to decrease radio or other signal interference, the position of RF antenna should be kept away
u t
from audio interface and audio alignment. Power alignment and audio alignment should not be parallel,
n
and power alignment should be far away from audio alignment.
Q ide
The differential audio traces must be routed according to the differential signal layout rule.
f
3.7.2. Microphone Interfaces Design
n
AIN channels come with internal bias supply for external electret microphone. A reference circuit is shown
in the following figure.
Co Close to Module Close to Microphone
GND GND GND GND
10pF 33pF
0603 0603 Differential
layout 10pF 33pF
0603 ESD
0603
MICP
10pF 33pF 10pF 33pF

0603 0603 0603
Module 0603
MICN Electret
Microphone
10pF 33pF ESD
0603 0603
10pF 33pF
0603 0603
GND GND GND GND
Figure 25: Reference Design for AIN

3.7.3. Receiver and Speaker Interface Design
Close to speaker
GND
10pF 33pF
Differential layout 0603 ESD
0603
SPKP
10pF 33pF
Module 0603 0603
SPKN
10pF 33pF
ESD
l
0603 0603
e
GND
t l
Figure 26: Handset Interface Design for AOUT1
e c t ia
u
Close to speaker
GND
Q ide n
10pF 33pF
Differential layout 0603 ESD
0603
Amplifier
circuit
SPKP
10pF 33pF
f
Module 0603 0603
SPKN
n
10pF 33pF
0603 0603 ESD
o
GND
C
Figure 27: Speaker Interface Design with an Amplifier for AOUT1
A suitable differential audio amplifier can be chosen from the Texas Instrument’s website
(http://www.ti.com/). There are also other excellent audio amplifier vendors in the market.

3.7.4. Earphone Interface Design
Close to Module
GND
Close to Socket
Differential GND
10pF 33pF 4.7uF
layout
MICN 0603 0603
10pF 33pF 10pF 33pF

MICP 0603 0603 0603 0603
Module 10pF 33pF

0603
l
0603
GND
e
LOUDSPKP 3
t
10pF 33pF 4
22uF 2
l
0603 0603 1
c a
AGND
GND
u e t i
Figure 28: Earphone Interface Design
Q ide n
3.7.5. Loud Speaker Interface Design
f
Close to Speaker
n
GND GND GND
o
Differential
layout
10pF 33pF ESD
0603 0603
C
0R
LOUDSPKP
Module 10pF 33pF
0603 0603
LOUDSPKN 0R 8 ohm
10pF 33pF ESD

0603 0603
GND GND GND
Figure 29: Loud Speaker Interface Design

3.7.6. Audio Characteristics
Table 17: Typical Electret Microphone Characteristics
Parameter Min. Typ. Max. Unit
Working Voltage 1.2 1.5 2.0 V
Working Current 200 500 uA
External Microphone Load Resistance 2.2 K Ohm
el
Table 18: Typical Speaker Characteristics
c t l
e ia
Load resistance 32 Ohm
t
Single-ended
u
AOUT1 Reference level 0 2.4 Vpp
n
Output
Q ide
Differential
Reference level 0 4.8 Vpp
f
Differential
Reference level 0 2×VBAT Vpp
n
AOUT2
Output
o
Single-ended
Reference level 0 VBAT Vpp
C
3.8. SIM Card Interface
The SIM interface supports the functionality of the GSM Phase 1 specification and also the functionality of
the new GSM Phase 2+ specification for FAST 64 kbps SIM card (intended for use with a SIM application
tool-kit.
The SIM interface is powered by an internal regulator in the module. Both 1.8V and 3.0V SIM cards are
supported, and Dual SIM Single Standby function is supported.

Table 19: Pin Definition of the SIM Interface
Alternate
Pin Name Pin No. Description
Function1)
Supply power for SIM card. Automatic detection of
SIM1_VDD 18 SIM1 card voltage. 3.0V±5% and 1.8V±5%.
Maximum supply current is around 10mA.
SIM1_CLK 19 SIM1 card clock.
SIM1_DATA 21 SIM1 card data I/O.
l
SIM1_RST 20 SIM1 card reset.
e
SIM1_PRESENCE 37 SIM1 card detection. DTR
t l
SIM_GND 16 SIM card ground.
c
Supply power for SIM card. Automatic detection of
e ia
SIM2_VDD 13 SIM2 card voltage. 3.0V±5% and 1.8V±5%.
t
Maximum supply current is around 10mA.
u n
SIM2_CLK 10 SIM2 card clock.
Q ide
SIM2_DATA 11 SIM2 card data I/O.
SIM2_RST 12 SIM2 card reset.
n f
NOTE
o
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.
C
The following figure is a reference design for SIM1 interface with an 8-pin SIM card holder.

VDD_EXT
10K
SIM_GND 100nF SIM_Holder
SIM1_VDD
VCC GND
SIM1_RST 22R
RST VPP
Module SIM1_CLK 22R
CLK IO
SIM1_PRESENCE
SIM1_DATA 22R
GND
33pF 33pF33pF33pF
l
TVS
t e
GND GND
c l
Figure 30: Reference Circuit for SIM1 Interface with an 8-pin SIM Card Holder
e t ia
If SIM1 card detection function is not used, keep SIM1_PRESENCE pin open. A reference circuit for a
u
6-pin SIM card socket is shown in the following figure.
Q ide n
SIM_GND 100nF
SIM_Holder
SIM1_VDD
VCC GND
SIM1_RST 22R
f
RST VPP
Module SIM1_CLK 22R
CLK IO
SIM1_PRESENCE
n
SIM1_DATA 22R
o
33pF33pF 33pF 33pF
C
TVS
GND GND
Figure 31: Reference Circuit for SIM1 Interface with a 6-pin SIM Card Holder
The following figure is a reference design for SIM2 interface with a 6-pin SIM card holder.

SIM_GND 100nF
SIM_Holder
SIM2_VDD
VCC GND
SIM2_RST 22R
RST VPP
Module SIM2_CLK 22R
CLK IO
SIM2_DATA 22R
33pF33pF 33pF 33pF

TVS
l
GND GND
t e
Figure 32: Reference Circuit for SIM2 Interface with a 6-pin SIM Card Holder
c a l
For more information of SIM card holder, you can visit http://www.amphenol.com/ and
e i
http://www.molex.com/.
u t
In order to enhance the reliability and availability of the SIM card in application, please conform to the
n
following criteria in the SIM circuit design:
Q ide
 Keep layout of SIM card as close to the module as possible. Assure the trace length is less than
200mm.

f
Keep SIM card signal away from RF and VBAT alignment.
 Assure the ground between module and SIM holder short and wide. Keep the width of ground no less
n
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 holder.
o
 To avoid cross talk between SIM_DATA and SIM_CLK, keep them away from each other and shield
them with surrounded ground.
C
 In order to offer good ESD protection, it is recommended to add a TVS diode array. For more
information of TVS diode, please visit http://www.onsemi.com/. The most important rule is to place
the ESD protection device close to the SIM card socket and make sure the nets 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 note 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 lines to improve EMI
suppression performance.

3.9. ADC
The module provides an ADC channel to measure the value of voltage. Please give priority to the use of
ADC0 channel. Command AT+QADC can read the voltage value applied on ADC0 pin. For details of this
AT command, please refer to document [1]. In order to improve the accuracy of ADC, the layout of ADC
should be surrounded by ground.
Table 20: Pin Definition of the ADC
l
e
ADC 6 Analog to digital converter.
c t a l
Table 21: Characteristics of the ADC
u e t i
Item Min. Typ. Max. Unit
n
Voltage Range 0 2.8 V
Q ide
ADC Resolution 10 bits
ADC Accuracy 2.7 mV
n f
o
3.10. Behaviors of the RI
C
Table 22: Behaviors of the RI
State RI Response
Standby HIGH
Change to LOW, and then:

1. Change to HIGH when call is established.
2. Change to HIGH when use ATH to hang up the call
Voice Call 3. Change to HIGH first when calling part hangs up and then change to LOW for
120ms indicating ―NO CARRIER‖ as an URC. After that, RI changes to HIGH
again.
4. Change to HIGH when SMS is received.
When a new SMS comes, the RI changes to LOW and holds low level for about
SMS
120ms, and then changes to HIGH.

Certain URCs can trigger 120ms low level on RI. For more details, please refer to
URC
document [1]
If the module is used as a caller, the RI would maintain high except when the URC or SMS is received.
When it is used as a receiver, the timing of RI is shown below.
RI
HIGH
Off-hook by “ATA”
l
LOW On-hook by “ATH”
SMS received
e
Idle Ring
c t l
Figure 33: RI Behavior as a Receiver When Voice Calling
u e RI
t ia
n
HIGH
Q ide
LOW
Idle Calling Talking On-hook Idle
n f
Figure 34: RI Behavior as a Caller
Co HIGH
LOW
RI 120ms
Idle or URC or
Talking SMS received
Figure 35: RI Behavior When URC or SMS Received

3.11. 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 23: Working State of the NETLIGHT
State Module Function
l
Off The module is not running.
e
64ms On/800ms Off The module is not synchronized with network.
t l
64ms On/2000ms Off The module is synchronized with network.
c a
64ms On/600ms Off GPRS data transmission after dialing the PPP connection.
u e t i
A reference circuit is shown as below.
n
Q ide
VBAT
n f
MC20
Module
o
300R
C
4.7K
NETLIGHT
47K
Figure 36: Reference Design for NETLIGHT

3.12. EASY Autonomous AGPS Technology
Supplying aiding information like ephemeris, almanac, rough last position, time and satellite status, can
help improve the acquisition sensitivity and the TTFF for a module. This is called as EASY technology and
MC20’s GNSS part supports it.
EASY technology works as embedded software which can accelerate TTFF by predicting satellite
navigation messages from received ephemeris. The GNSS part will calculate and predict orbit information
automatically up to 3 days after first receiving the broadcast ephemeris, and save the predicted
information into the internal memory. GNSS part of MC20 will use the information for positioning if no
l
enough information from satellites, so the function is helpful for positioning and TTFF improvement.
e
The EASY function can reduce TTFF to 5s in warm start. In this case, GNSS’s backup domain should be
t
valid. In order to gain enough broadcast ephemeris information from GNSS satellites, the GNSS part
c l
should receive the information for at least 5 minutes in good signal conditions after it fixes the position.
e ia
EASY function is enabled by default. Command ―$PMTK869,1,0*34‖ can be used to disable EASY
u t
function. For more details, please refer to document [2].
Q ide n
NOTE
In all-in-one solution, make sure the GNSS part is powered on before sending the PMTK command.
n f
3.13. EPO Offline AGPS Technology
Co
MC20 module features a function called EPO (Extended Prediction Orbit) which is a world leading
technology. When MC20 module is powered on, EPO function can be enabled via AT command
AT+QGNSSEPO=1. When the GSM part detected that the EPO data has expired, the EPO data will be
automatically downloaded to the GSM part’s FS from MTK server via GSM/GPRS network; and the GNSS
part will get the EPO data via build-in GNSS command from GSM's FS when it detected that the local
EPO data has expired. When there is no local EPO data or when the data has expired, MC20 module will
download the data (4KB) for 6 hours’ orbit predictions in order to achieve cold start in the shortest time,
and then continue to download the EPO data (48KB) for 3 days. The technology allows the module to
realize fast positioning. Command AT+QGNSSEPO=0 can turn off the EPO function.
NOTE
Make sure the EPO function is enabled if you need to download the EPO data.

3.14. Multi-tone AIC
MC20 module has a function called multi-tone AIC (Active Interference Cancellation) to decease
harmonic of RF noise from Wi-Fi, GSM, 3G and 4G.
Up to 12 multi-tone AIC embedded in the module can provide effective narrow-band interference and
jamming elimination. The GNSS signal could be demodulated from the jammed signal, which can ensure
better navigation quality. AIC function is enabled by default. Enabling AIC function will increase current
consumption by about 1mA @VCC=3.3V. The following commands can be used to set AIC function.
l
Enable AIC function: $PMTK 286,1*23
Disable AIC function: $PMTK 286,0*22
NOTE
c t e l
e ia
In all-in-one solution, make sure the GNSS part is powered on before sending these PMTK commands.
u n t
Q ide
n f
Co

4 Antenna Interface
MC20 has three antenna interfaces which are used for GSM antenna, GNSS antenna and BT antenna,
respectively. The Pin 41 is the GSM antenna pad; the Pin 15 is the GNSS antenna pad; and Pin 32 is the
BT antenna pad. The RF interface of the three antenna pads has an impedance of 50Ω.
el
4.1. GSM Antenna Interface
c t l
There is a GSM antenna pad named RF_ANT for MC20.
u e t ia
Table 24: Pin Definition of the RF_ANT
Q ide n
GND 40 Ground
RF_ANT 41 GSM antenna pad
f
GND 42 Ground
o n
4.1.1. Reference Design
C
The external antenna must be matched properly to achieve the best performance; so the matching circuit
is necessary. A reference design for GSM antenna is shown below.
0R
RF_ANT
MC20 Module NM NM
Figure 37: Reference Design for GSM Antenna

MC20 provides an RF antenna pad for antenna connection. The RF trace in host PCB connected to the
module’s RF antenna pad should be coplanar waveguide line or microstrip line, whose characteristic
impedance should be close to 50Ω. MC20 comes with grounding pads which are next to the antenna pad
in order to give a better grounding. Besides, a π type matching circuit is suggested to be used to adjust
the RF performance.
To minimize the loss on RF trace and RF cable, please pay attention to the design. The following table
shows the requirement on GSM antenna.
Table 25: Antenna Cable Requirements
l
Type Requirements
t e
GSM850/EGSM900 Cable insertion loss <1dB
c l
DCS1800/PCS1900 Cable insertion loss <1.5dB
u e
Table 26: Antenna Requirements
t ia
Q ide n
Type Requirements
Frequency Range Depend on the frequency band(s) provided by the network operator
≤2
f
VSWR
n
Gain (dBi) 1
o
Max. Input Power (W) 50
Input Impedance (Ω) 50
C
Polarization Type Vertical
4.1.2. RF Output Power
Table 27: RF Output Power
Frequency Max. Min.
GSM850 33dBm±2dB 5dBm±5dB
EGSM900 33dBm±2dB 5dBm±5dB
DCS1800 30dBm±2dB 0dBm±5dB

PCS1900 30dBm±2dB 0dBm±5dB
NOTE
In GPRS 4 slots TX mode, the maximum output power is reduced by 2.5dB. This design conforms to the
GSM specification as described in section 13.16 of 3GPP TS 51.010-1.
4.1.3. RF Receiving Sensitivity
l
Table 28: RF Receiving Sensitivity
t e
Frequency Receive Sensitivity
c l
GSM850 < -110dBm
e ia
EGSM900 < -110dBm
u t
DCS1800 < -110dBm
Q ide n
PCS1900 < -110dBm
4.1.4. Operating Frequencies
n f
Table 29: Operating Frequencies
o
Frequency Receive Transmit ARFCH
C
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
4.1.5. RF Cable Soldering
Soldering the RF cable to RF pad of module correctly will reduce the loss on the path of RF, please refer
to the following example of RF soldering.

el
Figure 38: RF Soldering Sample
c t a l
e i
4.2. GNSS Antenna Interface
u n t
The GNSS part of MC20 module supports both GPS and BeiDou systems. The RF signal is obtained from
Q ide
the GNSS_ANT pin. The impedance of RF trace should be controlled as 50 Ohm, and the trace length
should be kept as short as possible.
f
4.2.1. Antenna Specifications
n
The module can be connected to a dedicated GPS/BeiDou passive or active antenna to receive
o
GPS/BeiDou satellite signals. The recommended antenna specifications are given in the following table.
C
Table 30: Recommended Antenna Specifications
Antenna Type Specification
GPS frequency: 1575.42±2MHz

BeiDou frequency: 1602±4MHz
Passive Antenna VSWR: <2 (Typ.)
Polarization: RHCP or Linear
Gain: >0dBi
GPS frequency: 1575.42±2MHz
BeiDou frequency:1602±4MHz
Active Antenna VSWR: <2 (Typ.)
Polarization: RHCP or Linear
Noise figure: <1.5dB

Gain (antenna): >-2dBi

Gain (embedded LNA): 20dB (Typ.)
Total gain: >18dBi (Typ.)
4.2.2. Active Antenna
The following figure is a typical reference design with active antenna. In this mode, the antenna is
powered by GNSS_VCC.
Active Antenna
l
П matching circuit MC20 Module
R1
e
GNSS_ANT
t
0R
C2 NM
l
C1 NM
c
L1 47nH
u e t ia
n
R2 10R
GNSS_VCC
Q ide
f
Figure 39: Reference Design with Active Antenna
n
C1, R1 and C2 are reserved matching circuit for antenna impedance modification. By default, C1 and C2
o
are not mounted; R1 is 0 ohm.
C
The external active antenna is powered by GNSS_VCC. The voltage ranges from 2.8V to 4.3V, and the
typical value is 3.3V. If the voltage does not meet the requirements for powering the active antenna, an
external LDO should be used.
The inductor L1 is used to prevent the RF signal from leaking into the GNSS_VCC pin and route the bias
supply to the active antenna, and the recommended value of L1 is no less than 47nH. R2 can protect the
whole circuit in case the active antenna is shorted to ground.
NOTE
In all-in-one solution, please note that the power supply of GNSS_VCC is controlled by the GSM part
through AT command.

4.2.3. Passive Antenna
Passive Antenna
MC20 Module
П matching circuit
R1
GNSS_ANT
0R
C2 NM
C1 NM
t el
e c ia l
t
Figure 40: Reference Design with Passive Antenna
u n
The above figure is a typical reference design with passive antenna.
Q ide
C1, R1 and C2 are reserved matching circuit for antenna impedance modification. C1 and C2 are not
mounted by default; R1 is 0 ohm. Impedance of RF trace should be controlled as 50 ohm and the trace
f
length should be kept as short as possible.
o n
4.3. Bluetooth Antenna Interface
C
MC20 provides a Bluetooth antenna interface. Bluetooth is a wireless technology that allows devices to
communicate, or transmit data/voice, wirelessly over a short distance. It is described as a short-range
communication technology intended to replace the cables connecting portable and/or fixed devices while
maintaining high level of security. Bluetooth is standardized as IEEE802.15 and operates in the 2.4 GHz
range using RF technology. Its data rate is up to 3Mbps.
MC20 is fully compliant with Bluetooth specification 3.0, and supports profiles including SPP and HFP-AG.
The module provides a Bluetooth antenna pad named BT_ANT, and the pin definition is listed below.

Table 31: Pin Definition of the BT_ANT
BT_ANT 32 BT antenna pad
GND 31 Ground
The external antenna must be matched properly to achieve the best performance, so the matching circuit
is necessary. The connection is recommended as in the following figure:
el
0R
t
BT_ANT
e c
MC20 Module
ia l NM NM
u n t
Q ide
f
Figure 41: Reference Design for Bluetooth Antenna
o n
There are some suggestions for component placement and RF trace layout for Bluetooth RF traces:
C
 Antenna matching circuit should be closed to the antenna;
 The impedance of RF trace should be controlled as 50Ω;
 The RF traces should be kept far away from the high frequency signals and strong disturbing source.

5 Electrical, Reliability and Radio

Characteristics
l
5.1. Absolute Maximum Ratings
t e
Absolute maximum ratings for power supply and voltage on digital and analog pins of the module are
c l
listed in the following table:
e t ia
Table 32: Absolute Maximum Ratings
u n
Parameter Min. Max. Unit
Q ide
VBAT -0.3 +4.73 V
GNSS_VCC -0.3 +4.5 V
f
Peak Current of Power Supply (VBAT) 0 2 A
n
RMS Current of Power Supply (VBAT, during one
o
0 0.7 A
TDMA-frame)
Voltage at Digital Pins -0.3 3.08 V
C
Voltage at Analog Pins -0.3 3.08 V
Voltage at Digital/analog Pins in Power Down Mode -0.25 0.25 V
5.2. Operating Temperature
The operating temperature is listed in the following table:

Table 33: Operating Temperature
Operation temperature range 1) -35 +25 +75 ℃
Extended temperature range 2) -40 +85 ℃
NOTES
1)
1. Within operation temperature range, the module is 3GPP compliant.
l
2)
2. Within extended temperature range, the module remains the ability to establish and maintain a
voice, SMS, data transmission, emergency call, etc. There is no unrecoverable malfunction. There
t e
are also no effects on radio spectrum and no harm to radio network. Only one or more parameters like
l
Pout might reduce in their value and exceed the specified tolerances. When the temperature returns to
c
the normal operating temperature levels, the module will meet 3GPP compliant again.
u e t ia
n
5.3. Power Supply Ratings
Q ide
Table 34: Power Supply Ratings of GSM Part (GNSS is Powered off)
f
Parameter Description Conditions Min. Typ. Max. Unit
Voltage must stay within the
n
Supply voltage min/max values, including 3.3 4.0 4.6 V
o
voltage drop, ripple, and spikes.
VBAT Voltage drop
C
during Maximum power control level
400 mV
transmitting on GSM850 and EGSM900.
burst
Power down mode 220 uA
SLEEP mode @DRX=5 1.2 mA
Minimum functionality mode
AT+CFUN=0
IDLE mode 13 mA
Average supply SLEEP mode 0.98 mA
IVBAT
current AT+CFUN=4
IDLE mode 13 mA
SLEEP mode 1.0 mA
TALK mode
GSM850/EGSM9001) 208/209 mA
DCS1800/PCS19002) 142/146 mA

DATA mode, GPRS (3Rx, 2Tx)

GSM850/EGSM9001) 359/360 mA
DCS1800/PCS19002) 232/250 mA
DATA mode, GPRS (2 Rx, 3Tx)
GSM850/EGSM9001) 431/413 mA
DCS1800/PCS19002) 311/339 mA
DATA mode, GPRS (4 Rx, 1Tx)
GSM850/EGSM9001) 215/153 mA
DCS1800/PCS19002) 153/162 mA
DATA mode, GPRS (1Rx, 4Tx)
GSM850/EGSM9001) 499/4693) mA
l
DCS1800/PCS19002) 392/427 mA
e
Peak supply
t
current (during Maximum power control level
1.6 2 A
l
transmission on GSM850 and EGSM900.
c
slot)
NOTES
u e t ia
n
1)
1. Power control level PCL 5.
Q ide
2)
2. Power control level PCL 0.
3)
3. Under the GSM850 and EGSM900 spectrum, the power of 1Rx and 4Tx is reduced.
f
Table 35: Power Supply Ratings of GNSS Part
n
Parameter Description Conditions Min. Typ. Max. Unit
o
Voltage must stay
C
within the min/max
GNSS_
Supply voltage values, including 2.8 3.3 4.3 V
VCC
voltage drop, ripple,
and spikes.
IVCCP1) Peak supply current VCC=3.3V 150 mA
NOTE
1)
This figure can be used to determine the maximum current capability of power supply.

5.4. Current Consumption
Table 36: Current Consumption of GSM Part (GNSS is Powered off)
Condition Current Consumption
Voice Call
@power level #5 <300mA, Typical 174mA

GSM850 @power level #12, Typical 83mA
l
@power level #19, Typical 62mA
t e
EGSM900 @power level #12, Typical 83mA
l
c
e a
DCS1800 @power level #7, Typical 73mA
t i
u
n
PCS1900 @power level #7, Typical 76mA
Q ide
GPRS Data
DATA Mode, GPRS (3 Rx, 2Tx) CLASS 12
f
n
o
C

EGSM900


DATA Mode, GPRS (4 Rx,1Tx) CLASS 12
l
e
t
c l
a
e i
u t
n
Q ide
f
n
o
C
NOTE
GPRS Class 12 is the default setting. The GSM module can be configured from GPRS Class 1 to Class
12. Setting to lower GPRS class would make it easier to design the power supply for the GSM module.

Table 37: Current Consumption of the GNSS Part
Parameter Conditions Typ. Unit
IVCC @Acquisition @VCC=3.3V (GPS) 25 mA
IVCC @Tracking @VCC=3.3V (GPS) 19 mA
IVCC @Acquisition @VCC=3.3V (GPS+BeiDou) 23 mA
IVCC @Tracking @VCC=3.3V (GPS+BeiDou) 18 mA
IVCC @Standby @VCC=3.3V 0.3 mA
l
IBCKP @backup @V_BCKP=3.3V 14 uA
NOTE
c t e l
e ia
The tracking current is tested in following conditions:
t
 For Cold Start, 10 minutes after First Fix.
u
 For Hot Start, 15 seconds after First Fix.
Q ide
5.5. Electrostatic Discharge
n
f
Although the module is generally protected against Electrostatic Discharge (ESD), ESD protection
n
precautions should still be emphasized. Proper ESD handling and packaging procedures must be applied
o
throughout the processing, handling and operation of any applications using the module.
C
The measured ESD values of the module are shown in the following table.
Table 38: ESD Endurance (Temperature: 25ºC, Humidity: 45%)
Tested Point Contact Discharge Air Discharge
VBAT, GND ±5KV ±10KV
RF_ANT ±5KV ±10KV
GNSS_ANT ±5KV ±10KV
TXD, RXD ±2KV ±4KV
GNSS_TXD
±2KV ±4KV
GNSS_RXD

Others ±0.5KV ±1KV
t el
e c ia l
u n t
Q ide
n f
Co

6 Mechanical Dimensions
This chapter describes the mechanical dimensions of the module.
l
6.1. Mechanical Dimensions of Module
c t e l
u e t ia
Q ide n
n f
Co Figure 42: MC20 Top and Side Dimensions (Unit: mm)

t el
e c ia l
u n t
Q ide
n f
Figure 43: MC20 Bottom Dimensions (Unit: mm)
Co

6.2. Recommended Footprint
t el
e c ia l
u n t
Q ide
n f Figure 44: Recommended Footprint (Unit: mm)
NOTES
1.
2.
Co
For convenient maintenance, the module should be kept about 3mm away from the other
components in the host PCB.
The circular test points with a radius of 1.75mm in the above recommended footprint should be
treated as keepout areas. (―keepout‖ means do not pour copper on the mother board).

6.3. Top and Bottom View of the Module
t el
e c ia l
Figure 45: Top View of the Module
u n t
Q ide
n f
Co Figure 46: Bottom View of the Module
NOTE
These are design effect drawings of MC20 module. For more accurate pictures, please refer to the
module that you get from Quectel.

7 Storage and Manufacturing
7.1. Storage
l
MC20 module is stored in a vacuum-sealed bag. The storage restrictions are shown as below.
t e
1. Shelf life in the vacuum-sealed bag: 12 months at <40ºC and <90%RH.
c l
2. After the vacuum-sealed bag is opened, devices that need to be mounted directly must be:
e t ia
 Mounted within 72 hours at the factory environment of ≤30ºC and <60% RH.
u
 Stored at <10% RH.
Q ide n
3. Devices require baking before mounting, if any circumstance below occurs.
 When the ambient temperature is 23ºC±5ºC and the humidity indication card shows the humidity
is >10% before opening the vacuum-sealed bag.
f
 Device mounting cannot be finished within 72 hours when the ambient temperature is <30ºC and the
n
humidity is <60%.
 Stored at >10% RH.
o
4. If baking is required, devices should be baked for 48 hours at 125ºC±5ºC.
C
NOTE
As the plastic package cannot be subjected to high temperature, it should be removed from devices
before high temperature (125ºC) baking. If shorter baking time is desired, please refer to
IPC/JEDECJ-STD-033 for baking procedure.
7.2. Soldering
Push the squeegee to apply the solder paste on the surface of stencil, thus making the paste fill the
stencil openings and then penetrate to the PCB. The force on the squeegee should be adjusted properly
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 MC20. For more details, please
refer to document [12]
It is suggested that the peak reflow temperature is from 235ºC to 245ºC (for SnAg3.0Cu0.5 alloy). The
absolute maximum reflow temperature is 260ºC. To avoid damage to the module caused by repeated
heating, it is suggested that the module should be mounted after reflow soldering for the other side of
PCB has been completed. Recommended reflow soldering thermal profile is shown below:
℃
Preheat Heating Cooling
l
250
Liquids
e
217 Temperature
t
200℃
l
200
c
40s~60s
e ia
160℃
t
150
u n
70s~120s
Q ide
100
Between 1~3℃/S
f
50
o n50 100 150 200 250 300 s
C
Time(s)
Figure 47: Reflow Soldering Thermal Profile
7.3. Packaging
The modules are stored in 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
t el
e c ia l
t
Figure 48: Tape and Reel Specification
u
Q ide n
n f
Co
Table 39: Reel Packaging
Figure 49: Dimensions of Reel
MOQ for Minimum Minimum

Model Name
MP Package:250pcs Packagex4=1000pcs
Size: Size:
370mm×350mm×56mm 380mm×250mm×365mm
MC20 250pcs
N.W: 0.32kg N.W: 1.28kg
G.W: 1.08kg G.W: 4.8kg

8 Appendix A References
Table 40: Related Documents
SN Document Name Remark
l
[1] Quectel_MC20_AT_Commands_Manual MC20 AT commands manual
t e
Serial asynchronous automatic dialing
[2] ITU-T Draft new recommendation V.25ter
l
and control
c
Digital cellular telecommunications
e ia
[3] GSM 07.07 (Phase 2+); AT command set for GSM
t
Mobile Equipment (ME)
u
Support GSM 07.10 multiplexing
n
[4] GSM 07.10
protocol
Q ide
(Phase 2+); Use of Data Terminal
Equipment – Data Circuit terminating
[5] GSM 07.05
Equipment (DTE – DCE) interface for
f
Short Message Service (SMS) and
n
Cell Broadcast Service (CBS)
o
(Phase 2+); Specification of the SIM
[6] GSM 11.14 Application Toolkit for the Subscriber
C
Identity module – Mobile Equipment
(SIM – ME) interface
(Phase 2+); Specification of the
[7] GSM 11.11
Subscriber Identity module – Mobile
Equipment (SIM – ME) interface
[8] GSM 03.38 (Phase 2+); Alphabets and
language-specific information
(Phase 2); Mobile Station (MS)
[9] GSM 11.10
conformance specification; Part 1:
Conformance specification

[10] GSM_UART_Application_Note UART port application note
[11] GSM_EVB_User_Guide GSM EVB user guide
[12] Module_Secondary_SMT_User_Guide Module secondary SMT user guide
GSM Module Digital IO Application

[13] Quectel_GSM_Module_Digital_IO_Application_Note
Note
Table 41: Terms and Abbreviations
l
Abbreviation Description
e
ADC Analog-to-Digital Converter
c t l
AMR Adaptive Multi-Rate
e a
ARP Antenna Reference Point
u t i
ASIC Application Specific Integrated Circuit
n
BER Bit Error Rate
Q ide
BOM Bill of Material
BT Bluetooth
f
BTS Base Transceiver Station
n
CHAP Challenge Handshake Authentication Protocol
o
CS Coding Scheme
C
CSD Circuit Switched Data
CTS Clear to Send
DAC Digital-to-Analog Converter
DRX Discontinuous Reception
DSP Digital Signal Processor
DCE Data Communications Equipment (typically module)
DTE Data Terminal Equipment (typically computer, external controller)
DTR Data Terminal Ready

DTX Discontinuous Transmission
EFR Enhanced Full Rate
EGSM Enhanced GSM
EMC Electromagnetic Compatibility
ESD Electrostatic Discharge
ETS European Telecommunication Standard
l
FCC Federal Communications Commission (U.S.)
e
FDMA Frequency Division Multiple Access
t l
FR Full Rate
c a
FS File System
e t i
GMSK Gaussian Minimum Shift Keying
u n
GPRS General Packet Radio Service
Q ide
GSM Global System for Mobile Communications
G.W Gross Weight
f
HR Half Rate
n
I/O Input/Output
o
IC Integrated Circuit
C
IMEI International Mobile Equipment Identity
IOmax Maximum Output Load 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)
MT Mobile Terminated
N.W Net Weight
PAP Password Authentication Protocol
PBCCH Packet Switched Broadcast Control Channel
PCB Printed Circuit Board
l
PDU Protocol Data Unit
e
PPP Point-to-Point Protocol
t l
RF Radio Frequency
c a
RMS Root Mean Square (value)
e t i
RTC Real Time Clock
u n
RX Receive Direction
Q ide
SIM Subscriber Identification Module
SMS Short Message Service
f
TDMA Time Division Multiple Access
n
TE Terminal Equipment
o
TX Transmitting Direction
C
UART Universal Asynchronous Receiver & Transmitter
URC Unsolicited Result Code
USSD Unstructured Supplementary Service Data
VSWR Voltage Standing Wave Ratio
VOmax Maximum Output Voltage Value
VOnorm Normal Output Voltage Value
VOmin Minimum Output Voltage Value
VIHmax Maximum Input High Level Voltage Value

VIHmin Minimum Input High Level Voltage Value
VILmax Maximum Input Low Level Voltage Value
VILmin Minimum Input Low Level Voltage Value
VImax Absolute Maximum Input Voltage Value
VInorm Absolute Normal Input Voltage Value
VImin Absolute Minimum Input Voltage Value
l
VOHmax Maximum Output High Level Voltage Value
e
VOHmin Minimum Output High Level Voltage Value
t l
VOLmax Maximum Output Low Level Voltage Value
c a
VOLmin Minimum Output Low Level Voltage Value
e t i
Phonebook Abbreviations
u n
LD SIM Last Dialing phonebook (list of numbers most recently dialed)
Q ide
MC Mobile Equipment list of unanswered MT Calls (missed calls)
ON SIM (or ME) Own Numbers (MSISDNs) list
f
RC Mobile Equipment list of Received Calls
n
SM SIM phonebook
Co

9 Appendix B GPRS Coding Schemes

Four coding schemes are used in GPRS protocol. The differences between them are shown in the
following table.
l
Table 42: Description of Different Coding Schemes
e
Radio Block Data
t
Code Pre-coded Coded Punctured
Scheme USF excl.USF and BCS Tail Rate
l
Rate USF Bits Bits
c
BCS Kb/s
a
CS-1 1/2 3 3 181 40 4 456 0 9.05
e t i
CS-2 2/3 3 6 268 16 4 588 132 13.4
u n
CS-3 3/4 3 6 312 16 4 676 220 15.6
Q ide
CS-4 1 3 12 428 16 - 456 - 21.4
f
Radio block structure of CS-1, CS-2 and CS-3 is shown as the figure below.
n
Radio Block
o
USF BCS
C
Rate 1/2 convolutional coding
Puncturing
456 bits
Figure 50: Radio Block Structure of CS-1, CS-2 and CS-3

Radio block structure of CS-4 is shown as the following figure.
Radio Block
USF BCS
Block No coding
Code
456 bits
l
Figure 51: Radio Block Structure of CS-4
c t e l
u e t ia
Q ide n
n f
Co

10 Appendix C GPRS Multi-slot Classes

Twenty-nine classes of GPRS multi-slot modes are defined for MS in GPRS specification. Multi-slot
classes are product dependent, 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
l
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.
c t e
Table 43: GPRS Multi-slot Classes
l
e t ia
Multislot Class Downlink Slots Uplink Slots Active Slots
u n
1 1 1 2
Q ide
2 2 1 3
3 2 2 3
f
4 3 1 4
n
5 2 2 4
o
6 3 2 4
C
7 3 3 4
8 4 1 5
9 3 2 5
10 4 2 5
11 4 3 5
12 4 4 5

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MC20 Hardware Design

GSM/GPRS/GNSS Module Series

Quectel Wireless Solutions Co., Ltd.

Or our local office. For more information, please visit:

MC20_Hardware_Design Confidential / Released 1 / 93

About the Document

MC20_Hardware_Design Confidential / Released 2 / 93

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

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

MC20_Hardware_Design Confidential / Released 3 / 93

3.5.2.1. Power down Module Using the PWRKEY Pin .................................................. 39

4 Antenna Interface ............................................................................................................................... 65

5 Electrical, Reliability and Radio Characteristics ............................................................................ 72

MC20_Hardware_Design Confidential / Released 4 / 93

5.3. Power Supply Ratings ............................................................................................................. 73

6 Mechanical Dimensions .................................................................................................................... 79

7 Storage and Manufacturing .............................................................................................................. 83

MC20_Hardware_Design Confidential / Released 5 / 93

TABLE 1: KEY FEATURES (GMS/GPRS PART OF MC20) ...................................................................... 13

MC20_Hardware_Design Confidential / Released 6 / 93

TABLE 42: DESCRIPTION OF DIFFERENT CODING SCHEMES .......................................................... 91

MC20_Hardware_Design Confidential / Released 7 / 93

FIGURE 1: MODULE FUNCTIONAL DIAGRAM ....................................................................................... 17

MC20_Hardware_Design Confidential / Released 8 / 93

MC20_Hardware_Design Confidential / Released 9 / 93

MC20_Hardware_Design Confidential / Released 10 / 93

Your cellular terminal or mobile contains a transmitter and receiver. When it is ON ,

MC20_Hardware_Design Confidential / Released 11 / 93

2.1. General Description

MC20_Hardware_Design Confidential / Released 12 / 93

2.2. Key Features

The following table describes the detailed features of MC20 module.

Table 1: Key Features (GMS/GPRS Part of MC20)

GSM Class Small MS

 Class 4 (2W) at GSM850 and EGSM900

MC20_Hardware_Design Confidential / Released 13 / 93

Speech codec modes:

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

Antenna Interface Connected to antenna pad with 50 Ohm impedance control

MC20_Hardware_Design Confidential / Released 14 / 93

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

Update Rate  Up to 10Hz, 1Hz by default

Velocity Accuracy  Without aid: 0.1m/s

Acceleration Accuracy  Without aid: 0.1m/s²

MC20_Hardware_Design Confidential / Released 15 / 93

 Maximum Altitude: 18,000m

Radio frequency part

MC20_Hardware_Design Confidential / Released 16 / 93

2.4. Evaluation Board

MC20_Hardware_Design Confidential / Released 17 / 93

3.1. Pin of Module

3.1.1. Pin Assignment

Power SIM2 RESERVED AUDIO OTHER

Figure 2: Pin Assignment

Please keep all reserved pins open.