FCC ID: XMR201202M35 GSM/GPRS Module

M35 Hardware Design M35 Quectel Cellular Engine Hardware Design M35_HD_V1.0 M35_HD_V1.0 - 1 -

M35 Hardware Design Document Title M35 Hardware Design Revision Date Status 1.0 2012-02-06 Released Document Control ID M35_HD_V1.0 General Notes Quectel offers this information as a service to its customers, to support application and engineering efforts that use the products designed by Quectel. The information provided is based upon requirements specifically provided for customers of Quectel. Quectel has not undertaken any independent search for additional information, relevant to any information that may be in the customers possession. Furthermore, system validation of this product designed by Quectel within a larger electronic system remains the responsibility of the customer or the customers system integrator. All specifications supplied herein are subject to change. Copyright This document contains proprietary technical information of Quectel Co., Ltd. Copying this document, distribution to others, and communication of the contents thereof, are forbidden without permission. Offenders are liable to the payment of damages. All rights are reserved in the event of a patent grant or registration of a utility model or design. All specifications supplied herein are subject to change without notice at any time. Copyright Shanghai Quectel Wireless Solutions Ltd. 2012 M35_HD_V1.0 - 2 -

QuectelConfidential M35 Hardware Design Contents Contents ............................................................................................................................................ 3 Table Index ....................................................................................................................................... 5 Figure Index ...................................................................................................................................... 6 0. Revision history ............................................................................................................................ 8 1. Introduction ................................................................................................................................... 9 1.1. Related documents ............................................................................................................. 9 1.2. Terms and abbreviations .................................................................................................. 10 1.3. Directives and standards .................................................................................................. 12 1.3.1. FCC Statement ...................................................................................................... 12 1.3.2. FCC/IC Radiation exposure statement .................................................................. 12 1.3.3. Industry Canada licence ........................................................................................ 12 1.4. Safety cautions ................................................................................................................. 13 2. Product concept ........................................................................................................................... 15 2.1. Key features ..................................................................................................................... 15 2.2. Functional diagram .......................................................................................................... 17 2.3. Evaluation board .............................................................................................................. 18 3. Application interface ................................................................................................................... 19 3.1. Pin .................................................................................................................................... 20 3.1.1. Pin assignment ...................................................................................................... 20 3.1.2. Pin description ....................................................................................................... 21 3.2. Operating modes .............................................................................................................. 26 3.3. Power supply .................................................................................................................... 27 3.3.1. Feature of GSM power .......................................................................................... 27 3.3.2. Minimize supply voltage drop............................................................................... 27 3.3.3. Reference power design for the module ................................................................ 28 3.3.4. Monitor power supply ........................................................................................... 29 3.4. Power on and down scenarios .......................................................................................... 29 3.4.1. Power on ............................................................................................................... 29 3.4.2. Power down ........................................................................................................... 31 3.4.3. Restart ................................................................................................................... 35 3.5. Power saving .................................................................................................................... 36 3.5.1. Minimum functionality mode................................................................................ 36 3.5.2. Sleep mode ............................................................................................................ 36 3.5.3. Wake up the module from SLEEP mode .............................................................. 37 3.6. Summary of state transitions ............................................................................................ 37 3.7. RTC backup ..................................................................................................................... 37 3.8. Serial interfaces ................................................................................................................ 39 3.8.1. UART Port ............................................................................................................ 40 3.8.2. Debug Port ............................................................................................................ 44 3.8.3. UART Application ................................................................................................ 44 3.9. Audio interfaces ............................................................................................................... 48 M35_HD_V1.0 - 3 -

QuectelConfidential M35 Hardware Design 3.9.1. Decrease TDD noise and other noise .................................................................... 49 3.9.2. Microphone interfaces design ............................................................................... 50 3.9.3. Receiver interface design ...................................................................................... 50 3.9.4. Earphone interface design ..................................................................................... 51 3.9.5. Loud speaker interface design ............................................................................... 51 3.9.6. Audio characteristics ............................................................................................. 52 3.10. SIM card interface .......................................................................................................... 52 3.10.1. SIM card application ........................................................................................... 52 3.10.2. 6 Pin SIM cassette ............................................................................................... 54 3.12. Behaviors of the RI ........................................................................................................ 55 3.13. Network status indication ............................................................................................... 57 3.14. Operating status indication ............................................................................................. 57 4. Antenna interface ........................................................................................................................ 59 4.1. RF reference design ......................................................................................................... 59 4.2. RF output power ............................................................................................................... 60 4.3. RF receiving sensitivity.................................................................................................... 60 4.4. Operating frequencies ...................................................................................................... 60 4.5. RF cable soldering ........................................................................................................... 60 5. Electrical, reliability and radio characteristics ............................................................................ 62 5.1. Absolute maximum ratings .............................................................................................. 62 5.2. Operating temperature ...................................................................................................... 62 5.3. Power supply ratings ........................................................................................................ 62 5.4. Current consumption ........................................................................................................ 63 5.5. Electro-static discharge .................................................................................................... 64 6. Mechanical dimensions ............................................................................................................... 65 6.1. Mechanical dimensions of module ................................................................................... 65 6.2. Footprint of recommendation ........................................................................................... 67 6.3. Top view of the module ................................................................................................... 68 6.4. Bottom view of the module .............................................................................................. 69 7. Storage and Manufacturing ......................................................................................................... 70 7.1. Storage ............................................................................................................................. 70 7.3. Packaging ......................................................................................................................... 72 Appendix A: GPRS coding schemes ............................................................................................... 73 Appendix B: GPRS multi-slot classes............................................................................................. 74 M35_HD_V1.0 - 4 -

QuectelConfidential M35 Hardware Design Table Index TABLE 1: RELATED DOCUMENTS .................................................................................................... 9 TABLE 2: TERMS AND ABBREVIATIONS ...................................................................................... 10 TABLE 3: MODULE KEY FEATURES ............................................................................................... 15 TABLE 4: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE 17 TABLE 5: M35 PIN ASSIGNMENT..................................................................................................... 20 TABLE 6: PIN DESCRIPTION ............................................................................................................. 21 TABLE 7: OVERVIEW OF OPERATING MODES ............................................................................ 26 TABLE 8: SUMMARY OF STATE TRANSITION ............................................................................. 37 TABLE 9: LOGIC LEVELS OF THE UART INTERFACE ................................................................. 40 TABLE 10: PIN DEFINITION OF THE UART INTERFACES .......................................................... 40 TABLE 11: PIN DEFINITION OF AUDIO INTERFACE ................................................................... 48 TABLE 12: AOUT2 OUTPUT CHARACTERISTICS ......................................................................... 49 TABLE 13: TYPICAL ELECTRET MICROPHONE CHARACTERISTICS ...................................... 52 TABLE 14: TYPICAL SPEAKER CHARACTERISTICS ................................................................... 52 TABLE 15: PIN DEFINITION OF THE SIM INTERFACE ................................................................ 53 TABLE 16: PIN DESCRIPTION OF AMPHENOL SIM CARD HOLDER......................................... 54 TABLE 17: BEHAVIORS OF THE RI.................................................................................................. 55 TABLE 18: WORKING STATE OF THE NETLIGHT ........................................................................ 57 TABLE 19: PIN DEFINITION OF THE STATUS ............................................................................... 57 TABLE 20: PIN DEFINITION OF THE ANTENNA INTERFACE .................................................... 59 TABLE 21: THE MODULE CONDUCTED RF OUTPUT POWER ................................................... 60 TABLE 22: THE MODULE CONDUCTED RF RECEIVING SENSITIVITY ................................... 60 TABLE 23: THE MODULE OPERATING FREQUENCIES ............................................................... 60 TABLE 24: ABSOLUTE MAXIMUM RATINGS ................................................................................ 62 TABLE 25: OPERATING TEMPERATURE ........................................................................................ 62 TABLE 26: THE MODULE POWER SUPPLY RATINGS ................................................................. 62 TABLE 27: THE MODULE CURRENT CONSUMPTION ................................................................. 63 TABLE 28: THE ESD ENDURANCE (TEMPERATURE:25,HUMIDITY:45 %) .......................... 64 TABLE 29: DESCRIPTION OF DIFFERENT CODING SCHEMES .................................................. 73 TABLE 30: GPRS MULTI-SLOT CLASSES ....................................................................................... 74 M35_HD_V1.0 - 5 -

QuectelConfidential M35 Hardware Design Figure Index FIGURE 1: MODULE FUNCTIONAL DIAGRAM ............................................................................. 18 FIGURE 2: PIN ASSIGNMENT ........................................................................................................... 20 FIGURE 3: RIPPLE IN SUPPLY VOLTAGE DURING TRANSMITTING BURST.......................... 27 FIGURE 4: REFERENCE CIRCUIT OF THE VBAT INPUT .............................................................. 28 FIGURE 5: REFERENCE CIRCUIT OF THE SOURCE POWER SUPPLY INPUT .......................... 28 FIGURE 6: TURN ON THE MODULE USING DRIVING CIRCUIT ................................................ 30 FIGURE 7: TURN ON THE MODULE USING KEYSTROKE........................................................... 30 FIGURE 8: TIMING OF TURNING ON SYSTEM .............................................................................. 31 FIGURE 9: TIMING OF TURNING OFF THE MODULE .................................................................. 32 FIGURE 10: REFERENCE CIRCUIT FOR EMERG_OFF BY USING DRIVING CIRCUIT ............ 34 FIGURE 11: REFERENCE CIRCUIT FOR EMERG_OFF BY USING BUTTON ............................. 34 FIGURE 12: TIMING OF RESTARTING SYSTEM ............................................................................ 35 FIGURE 13: TIMING OF RESTARTING SYSTEM AFTER EMERGENCY SHUTDOWN ............. 35 FIGURE 14: RTC SUPPLY FROM NON-CHARGEABLE BATTERY .............................................. 38 FIGURE 15: RTC SUPPLY FROM RECHARGEABLE BATTERY ................................................... 38 FIGURE 16: RTC SUPPLY FROM CAPACITOR ............................................................................... 38 FIGURE 17: SEIKO XH414H-IV01E CHARGE CHARACTERISTICS ............................................. 39 FIGURE 18: CONNECTION OF ALL FUNCTIONAL UART PORT ................................................. 42 FIGURE 19: CONNECTION OF THREE LINES UART PORT .......................................................... 42 FIGURE 20: CONNECTION OF UART PORT ASSOCIATED HARDWARE FLOW CONTROL .. 43 FIGURE 21: CONNECTION OF SOFTWARE UPGRADE ................................................................ 43 FIGURE 22: CONNECTION OF SOFTWARE DEBUG...................................................................... 44 FIGURE 23: 3.3V LEVEL MATCH CIRCUIT ..................................................................................... 45 FIGURE 24: 5V LEVEL MATCH CIRCUIT ........................................................................................ 46 FIGURE 25: RS232 LEVEL MATCH CIRCUIT .................................................................................. 47 FIGURE 26: MICROPHONE INTERFACE DESIGN OF AIN1&AIN2 .............................................. 50 FIGURE 27: RECEIVER INTERFACE DESIGN OF AOUT1 ............................................................. 50 FIGURE 28: EARPHONE INTERFACE DESIGN ............................................................................... 51 FIGURE 29: LOUD SPEAKER INTERFACE DESIGN ...................................................................... 51 FIGURE 30: REFERENCE CIRCUIT OF THE 6 PINS SIM CARD ................................................... 53 FIGURE 31: AMPHENOL C707 10M006 512 2 SIM CARD HOLDER ............................................. 54 FIGURE 32: RI BEHAVIOR OF VOICE CALLING AS A RECEIVER ............................................. 55 FIGURE 33: RI BEHAVIOR OF DATA CALLING AS A RECEIVER .............................................. 56 FIGURE 34: RI BEHAVIOR AS A CALLER ....................................................................................... 56 FIGURE 35: RI BEHAVIOR OF URC OR SMS RECEIVED .............................................................. 56 FIGURE 36: REFERENCE CIRCUIT OF THE NETLIGHT ............................................................... 57 FIGURE 37: REFERENCE CIRCUIT OF THE STATUS .................................................................... 58 FIGURE 38: REFERENCE CIRCUIT OF RF ....................................................................................... 59 FIGURE 39: RF SOLDERING SAMPLE ............................................................................................. 61 FIGURE 40: M35 TOP AND SIDE DIMENSIONSUNIT: MM ................................................... 65 FIGURE 41: M35 BOTTOM DIMENSIONSUNIT: MM ............................................................. 66 M35_HD_V1.0 - 6 -

QuectelConfidential M35 Hardware Design FIGURE 42: FOOTPRINT ONE OF RECOMMENDATIONUNIT: MM .................................... 67 FIGURE 43: TOP VIEW OF THE MODULE ....................................................................................... 68 FIGURE 44: BOTTOM VIEW OF THE MODULE .............................................................................. 69 FIGURE 45: PASTE APPLICATION ................................................................................................... 71 FIGURE 46: RAMP-SOAK-SPIKE REFLOW PROFILE .................................................................... 72 FIGURE 47: MODULE TRAY .............................................................................................................. 72 FIGURE 48: RADIO BLOCK STRUCTURE OF CS-1, CS-2 AND CS-3 ........................................... 73 FIGURE 49: RADIO BLOCK STRUCTURE OF CS-4 ........................................................................ 73 M35_HD_V1.0 - 7 -

QuectelConfidential M35 Hardware Design 0. Revision history Revision Date Author Description of change 1.0 2011-12-29 Luka WU Initial M35_HD_V1.0 - 8 -

QuectelConfidential M35 Hardware Design 1. Introduction This document defines Module M35 and describes its hardware interface which are connected with the customer application and the air interface. This document can help customers quickly understand the interface specifications, electrical and mechanical details of M35. Associated with application notes and user guide, customers can use M35 to design and set up mobile applications easily. 1.1. Related documents Table 1: Related documents SN Document name Remark

[1] M35_ATC AT commands set

[2]

ITU-T Draft new Serial asynchronous automatic dialing and control recommendation V.25ter

[3]

GSM 07.07 Digital cellular telecommunications (Phase 2+); AT

[4]

[5]

GSM 07.10 GSM 07.05 command set for GSM Mobile Equipment (ME) Support GSM 07.10 multiplexing protocol Digital cellular telecommunications (Phase 2+); Use of Data Terminal Equipment Data Circuit terminating Equipment (DTE DCE) interface for Short Message Service (SMS) and Cell Broadcast Service (CBS)

[6]

GSM 11.14 Digital cellular telecommunications (Phase 2+);

Specification of the SIM Application Toolkit for the Subscriber Identity module Mobile Equipment (SIM ME) interface

[7]

GSM 11.11 Digital cellular telecommunications (Phase 2+);

Specification of the Subscriber Identity module Mobile Equipment (SIM ME) interface

[8]

GSM 03.38 Digital cellular telecommunications (Phase 2+);

Alphabets and language-specific information

[9]

GSM 11.10 Digital cellular telecommunications (Phase 2); Mobile Station (MS) conformance specification; Part 1:

Conformance specification

[10] GSM_UART_AN UART port application notes

[11] GSM_FW_Upgrade_Tool_ GSM Firmware upgrade tool lite GS2 user guide Lite_GS2_UDG

[12] M35_EVB_UGD M35 EVB user guide M35_HD_V1.0 - 9 -

QuectelConfidential M35 Hardware Design 1.2. Terms and abbreviations Table 2: Terms and abbreviations Abbreviation Description ADC AMR ARP ASIC BER BOM BTS Analog-to-Digital Converter Adaptive Multi-Rate Antenna Reference Point Application Specific Integrated Circuit Bit Error Rate Bill Of Material Base Transceiver Station CHAP Challenge Handshake Authentication Protocol CS CSD CTS DAC DRX DSP DCE DTE DTR DTX EFR EGSM EMC ESD ETS FCC Coding Scheme Circuit Switched Data Clear To Send Digital-to-Analog Converter Discontinuous Reception Digital Signal Processor Data Communications Equipment (typically module) Data Terminal Equipment (typically computer, external controller) Data Terminal Ready Discontinuous Transmission Enhanced Full Rate Enhanced GSM Electromagnetic Compatibility Electrostatic Discharge European Telecommunication Standard Federal Communications Commission (U.S.) FDMA Frequency Division Multiple Access FR GMSK GPRS GSM HR I/O IC IMEI Imax Inorm kbps LED Full Rate Gaussian Minimum Shift Keying General Packet Radio Service Global System for Mobile Communications Half Rate Input/Output Integrated Circuit International Mobile Equipment Identity Maximum Load Current Normal Current Kilo Bits Per Second Light Emitting Diode M35_HD_V1.0 - 10 -

QuectelConfidential M35 Hardware Design Li-Ion Lithium-Ion Abbreviation Description MO MS MT PAP Mobile Originated Mobile Station (GSM engine) Mobile Terminated Password Authentication Protocol PBCCH Packet Switched Broadcast Control Channel PCB PDU PPP RF RMS RTC RX SIM SMS Printed Circuit Board Protocol Data Unit Point-to-Point Protocol Radio Frequency Root Mean Square (value) Real Time Clock Receive Direction Subscriber Identification Module Short Message Service TDMA Time Division Multiple Access TE TX UART URC USSD VSWR Vmax Vnorm Vmin VIHmax VIHmin VILmax VILmin VImax VImin Terminal Equipment Transmitting Direction Universal Asynchronous Receiver & Transmitter Unsolicited Result Code Unstructured Supplementary Service Data Voltage Standing Wave Ratio Maximum Voltage Value Normal Voltage Value Minimum Voltage Value Maximum Input High Level Voltage Value Minimum Input High Level Voltage Value Maximum Input Low Level Voltage Value Minimum Input Low Level Voltage Value Absolute Maximum Input Voltage Value Absolute Minimum Input Voltage Value VOHmax Maximum Output High Level Voltage Value VOHmin VOLmax VOLmin Minimum Output High Level Voltage Value Maximum Output Low Level Voltage Value Minimum Output Low Level Voltage Value Phonebook abbreviations FD LD MC ON RC SIM Fix Dialing phonebook SIM Last Dialing phonebook (list of numbers most recently dialed) Mobile Equipment list of unanswered MT Calls (missed calls) SIM (or ME) Own Numbers (MSISDNs) list Mobile Equipment list of Received Calls M35_HD_V1.0 - 11 -

QuectelConfidential M35 Hardware Design SM SIM phonebook 1.3. Directives and standards The M35 module is designed to comply with the FCC statements. FCC ID is XMR201202M35. The Host system using M35, should have label indicated FCC ID: XMR201202M35. 1.3.1. FCC Statement 1. This device complies with Part 15 of the FCC rules. Operation is subject to the following conditions:

a) This device may not cause harmful interference. b) This device must accept any interference received, including interference that may cause undesired operation. 2. Changes or modifications not expressly approved by the party responsible for compliance could void the users authority to operate the equipment. 1.3.2. FCC/IC Radiation exposure statement This equipment complies with FCC/IC radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with minimum distance 20cm between the radiator and your body as well as kept minimum 20cm from radio antenna depending on the portable or Mobile status of this module usage. The manual of the host system, which uses M35, must include RF exposure warning statement to advice user should keep minimum 20cm from the radio antenna of M35 module depending on portable or Mobile status. 1.3.3. Industry Canada licence Under Industry Canada regulations, this radio transmitter may only operate using an antenna of a type and maximum (or lesser) gain approved for the transmitter by Industry Canada. To reduce potential radio interference to other users, the antenna type and its gain should be so chosen that the equivalent isotropically radiated power (e.i.r.p.) is not more than that necessary for successful. The host system using M35 should have label indicating transmitter module IC:

10224-201202M35. This radio transmitter (identify the device by certification number, or module number if Category II) has been approved by Industry Canada to operate with the antenna type listed below with the M35_HD_V1.0 - 12 -

QuectelConfidential M35 Hardware Design maximum permissible gain and required antenna impedance for each antenna type indicated. Antenna types not included in this list, having a gain greater than the maximum gain indicated for that type, are strictly prohibited for use with this device. The following list of antenna is indicating the maximum permissible antenna gain. Type Maximum Gain Impedance External Antenna Monopole Vehicular antenna Internal Antenna Monopole PIFA FPC PCB 2dBi 2dBi 2dBi 2dBi 2dBi 2dBi 50 50 50 50 50 50 1.4. Safety cautions The following safety precautions must be observed during all phases of the operation, such as usage, service or repair of any cellular terminal or mobile incorporating M35 module. Manufacturers of the cellular terminal should send the following safety information to users and operating personnel and to incorporate these guidelines into all manuals supplied with the product. If not so, Quectel does not take on any liability for customer failure to comply with these precautions. When in a hospital or other health care facility, observe the restrictions about the use of mobile. Switch the cellular terminal or mobile off. Medical equipment may be sensitive to not operate normally for RF energy interference. Switch off the cellular terminal or mobile before boarding an aircraft. Make sure it switched off. The operation of wireless appliances in an aircraft is forbidden to prevent interference with communication systems. Forget to think much of these instructions may lead to the flight safety or offend against local legal action, or both. Do not operate the cellular terminal or mobile in the presence of flammable gas or fume. Switch off the cellular terminal when you are near petrol station, fuel depot, chemical plant or where blasting operations are in progress. Operation of any electrical equipment in potentially explosive atmosphere can constitute a safety hazard. M35_HD_V1.0 - 13 -

QuectelConfidential M35 Hardware Design Your cellular terminal or mobile receives and transmits radio frequency energy while switched on. RF interference can occur if it is used close to TV set, radio, computer or other electric equipment. Road safety comes first! Do not use a hand-held cellular terminal or mobile while driving a vehicle, unless it is securely mounted in a holder for hands-free operation. Before making a call with a hand-held terminal or mobile, park the vehicle. GSM cellular terminals or mobiles operate over radio frequency signal and cellular network and cannot be guaranteed to connect in all conditions, for example no mobile fee or an invalid SIM card. While you are in this condition and need emergent help, Please Remember using emergency call. In order to make or receive call, the cellular terminal or mobile must be switched on and in a service area with adequate cellular signal strength. Some networks do not allow for emergency call if certain network services or phone features are in use (e.g. lock functions, fixed dialing etc.). You may have to deactivate those features before you can make an emergency call. Also, some networks require that a valid SIM card be properly inserted in cellular terminal or mobile. M35_HD_V1.0 - 14 -

QuectelConfidential M35 Hardware Design 2. Product concept M35 is a Quad-band GSM/GPRS engine that works at frequencies of GSM850MHz, GSM900MHz, DCS1800MHz and PCS1900MHz. The M35 features GPRS multi-slot class 12 and supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. For more details about GPRS multi-slot classes and coding schemes, please refer to Appendix A and Appendix B. With a tiny profile of 19.9mm 23.6mm 2.65mm, the module can meet the requirements of almost all M2M applications, including Tracking and Tracing, Industrial PDA, Wireless POS, Intelligent Measurement, Remote Controlling, etc. M35 is an SMD type module with LCC package, which can be embedded in customer applications. It provides abundant hardware interfaces between the module and customers host board. Designed with power saving technique, the current consumption of M35 module is as low as 0.9 mA in SLEEP mode when DRX is 5. M35 is integrated with Internet service protocols, which are TCP/IP, UDP, FTP and PPP. Extended AT commands have been developed for customer to use these Internet service protocols easily. The module fully complies to FCC statements and RoHS directive of the European Union. 2.1. Key features Table 3: Module key features Feature Power supply Implementation Single supply voltage 3.3V ~ 4.6V Typical supply voltage 4V Power saving Typical power consumption in SLEEP mode: 0.9 mA@ DRX=5 Frequency bands GSM class Transmitting power GPRS connectivity 0.7 mA@ DRX=9 Quad-band: GSM850, GSM900, DCS1800, PCS1900. The module can search these frequency bands automatically The frequency bands can be set by AT command. Compliant with GSM Phase 2/2+

Small MS Class 4 (2W) at GSM850 and GSM900 Class 1 (1W) at DCS1800 and PCS1900 GPRS multi-slot class 12 (default) GPRS multi-slot class 1~12 (configurable) GPRS mobile station class B M35_HD_V1.0 - 15 -

QuectelConfidential M35 Hardware Design Temperature range DATA GPRS:

CSD:

SMS FAX SIM interface Audio features UART interface Phonebook management Normal operation: -35C ~ +80C Restricted operation: -40C ~ -35C and +80C ~ +85C 1) Storage temperature: -45C ~ +90C GPRS data downlink transfer: max. 85.6 kbps GPRS data uplink transfer: max. 85.6 kbps Coding schemes: CS-1, CS-2, CS-3 and CS-4 Support the protocols PAP (Password Authentication Protocol) usually used for PPP connections Internet service protocols TCP/UDP/FTP/HTTP Support Packet Switched Broadcast Control Channel (PBCCH) CSD transmission rates: 2.4, 4.8, 9.6, 14.4 kbps non-transparent Support Unstructured Supplementary Services Data (USSD) Text and PDU mode SMS storage: SIM card Group 3 Class 1 and Class 2 Support SIM card: 1.8V, 3V Speech codec modes:

Half Rate (ETS 06.20) Full Rate (ETS 06.10) Enhanced Full Rate (ETS 06.50 / 06.60 / 06.80) Adaptive Multi-Rate (AMR) Echo Cancellation 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 Use for AT command, GPRS data and CSD data Multiplexing function Support autobauding from 4800 bps to 115200 bps Debug Port:

Two lines on debug UART port interface DBG_TXD and DBG_RXD Debug Port only used for software debugging Support phonebook types: SM, ME, FD, ON, MT SIM Application Toolkit Support SAT class 3, GSM 11.14 Release 99 Real time clock Implemented Physical characteristics Size:

19.90.15 23.60.15 2.650.2mm Weight: 3g Firmware upgrade Firmware upgrade via UART Port Antenna interface Connected via 50 Ohm antenna pad M35_HD_V1.0 - 16 -

QuectelConfidential M35 Hardware Design Table 4: Coding schemes and maximum net data rates over air interface Coding scheme 1 Timeslot 2 Timeslot 4 Timeslot CS-1:

CS-2:

CS-3:

CS-4:

9.05kbps 13.4kbps 15.6kbps 21.4kbps 18.1kbps 26.8kbps 31.2kbps 42.8kbps 36.2kbps 53.6kbps 62.4kbps 85.6kbps 2.2. Functional diagram The following figure shows a block diagram of the M35 module and illustrates the major functional parts:

Power management Baseband The GSM radio frequency part The Peripheral interface SIM interface Audio interface UART interface Power supply RF interface Turn on/off interface RTC interface M35_HD_V1.0 - 17 -

QuectelConfidential M35 Hardware Design Figure 1: Module functional diagram 2.3. Evaluation board In order to help customer to develop applications with M35, Quectel supplies an evaluation board

(EVB), RS-232 to USB cable, power adapter, earphone, antenna and other peripherals to control or test the module. For details, please refer to the document [12]. M35_HD_V1.0 - 18 -

MT6252D32.768KControl26MPower supplyUARTSIMVDD_EXTAUDIOPWRKEYEMERG_OFFVRTCRF_ANTENNAPA TQM6M4068Application Interface (42-SMD Pads) QuectelConfidential M35 Hardware Design 3. Application interface The module is equipped with 42 pin SMT pad and it adopts LCC package. Detailed descriptions on Sub-interfaces included in these pads are given in the following chapters:

Power supply Turn on/off Power saving RTC UART interfaces Audio interfaces SIM interface M35_HD_V1.0 - 19 -

QuectelConfidential M35 Hardware Design 3.1. Pin 3.1.1. Pin assignment Figure 2: Pin assignment Table 5: M35 pin assignment PIN NO. PIN NAME I/O PIN NO. PIN NAME I/O 1 3 5 7 9 AGND MIC2N MIC1N SPK1P LOUDSPKP 11 EMERG_OFF I I O O I 2 4 6 8 10 12 MIC2P MIC1P SPK1N LOUDSPKN PWRKEY STATUS I I O O I O M35_HD_V1.0 - 20 -

QuectelConfidential M35 Hardware Design 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 NETLIGHT DBG_TXD RESERVED VDD_EXT RXD CTS DCD SIM_VDD O O O I O O O SIM_DATA I/O SIM_GND VBAT GND GND RF_ANT RESERVED I I/O 14 16 18 20 22 24 26 28 30 32 34 36 38 40 DBG_RXD RESERVED RESERVED DTR TXD RTS RI SIM_RST SIM_CLK VRTC VBAT GND GND GND 42 RESERVED I I O I O O O I/O I 3.1.2. Pin description Table 6: Pin description Power supply PIN NAME VBAT PIN NO. 33, 34 I/

O DESCRIPTION DC COMMENT CHARACTERISTICS I Main power supply of Vmax= 4.6V Make sure that supply module:

Vmin=3.3V sufficient current in a VBAT=3.3V~4.6V Vnorm=4.0V transmitting burst which typically rises to 1.6A. VRTC 32 I/

Power supply for RTC VImax=VBAT If unused, keep this O when VBAT is not VImin=2.6V pin open. supplied for the VInorm=2.8V system. VOmax=2.85V Charging for backup VOmin=2.6V battery or golden VOnorm=2.8V capacitor when the Iout(max)= 730uA VBAT is supplied. Iin=2.6~5 uA VDD_EXT 19 O Supply 2.8V voltage Vmax=2.9V 1. If unused, keep this for external circuit. Vmin=2.7V pin open. Vnorm=2.8V Imax=20mA 2. Recommended to add a 2.2~4.7uF M35_HD_V1.0 - 21 -

QuectelConfidential M35 Hardware Design bypass capacitor, when using this pin for power supply. Ground GND 35, 36, 37, 38, 40 Turn on/off PIN NAME PWRKEY PIN NO. 10 I/

O I DESCRIPTION DC COMMENT CHARACTERISTICS Power on/off key. VILmax=

Pulled up to VBAT PWRKEY should be 0.1*VBAT internally. pulled down for a VIHmin=

moment to turn on or 0.6*VBAT turn off the system. VImax=VBAT Emergency shutdown PIN NAME EMERG_ OFF PIN NO. 11 I/

O I DESCRIPTION DC COMMENT CHARACTERISTICS Emergency off. Pulled VILmax=0.4V Open drain/collector down for at least VIHmin=2.2V driver required in 20ms, which will turn Vopenmax=2.8V off the module in case of emergency. Use it only when normal shutdown through PWRKEY or AT command cannot perform well. cellular device application. If unused, keep this pin open. Module indicator PIN NAME STATUS PIN NO. 12 I/

O O DESCRIPTION DC COMMENT CHARACTERISTICS Indicate module VOHmin=

If unused, keep this operating status. High 0.85*VDD_EXT pin open. level indicates module VOLmax=

is power-on and low 0.15*VDD_EXT level indicates power-down. Audio interface PIN NAME PIN MIC1P MIC1N NO. 4 5 I/

O I DESCRIPTION DC COMMENT CHARACTERISTICS Channel one of positive and negative If unused, keep these pins open. M35_HD_V1.0 - 22 -

QuectelConfidential M35 Hardware Design MIC2P MIC2N SPK1N SPK1P AGND voice-band input 2 I Channel two of 3 positive and negative voice-band input 6, O Channel one of 7 1 positive and negative voice-band output Cooperate with LOUDSPKP LOUDSPKN 89 O Channel two of positive and negative LOUDSPKP voice-band output If unused, keep these pins open. If unused, keep this pin open. 1. If unused, keep these pins open. 2. Embedded amplifier of class AB internally. 3. Support both Voice and ring. Net status indicator PIN NAME PIN NO. I/

O DESCRIPTION DC COMMENT CHARACTERISTICS NETLIGHT 13 O Network status VOHmin=

If unused, keep this indication 0.85*VDD_EXT pin open. VOLmax=

0.15*VDD_EXT Main UART port PIN NAME PIN NO. I/

O DESCRIPTION DC COMMENT CHARACTERISTICS DTR RXD TXD CTS RTS DCD RI 20 21 22 23 24 25 26 I Data terminal ready VILmin=-0.3V If only use TXD, I Receiving data VILmax=

RXD and GND to O Transmitting data 0.25*VDD_EXT communicate, O Clear to send I Request to send O Data carrier detection O Ring indicator VIHmin=

recommended keeping 0.75*VDD_EXT other pins open, VIHmax=

except RTS. Pull VDD_EXT+0.3V down RTS. VOHmin=

0.85*VDD_EXT VOLmax=

0.15*VDD_EXT Debug UART port PIN NAME PIN NO. I/

O DESCRIPTION DC COMMENT CHARACTERISTICS M35_HD_V1.0 - 23 -

QuectelConfidential M35 Hardware Design DBG_RXD 14 I UART interface for VILmin=-0.3V If unused, keep these debugging only. VILmax=

pins open. DBG_TXD 15 O 0.25*VDD_EXT VIHmin=

0.75*VDD_EXT VIHmax=

VDD_EXT+0.3V VOHmin=

0.85*VDD_EXT VOLmax=

0.15*VDD_EXT SIM interface PIN NAME PIN NO. I/

O DESCRIPTION DC COMMENT CHARACTERISTICS SIM_ VDD 27 O Power supply for SIM The voltage can be 1. All signals of SIM card selected by software interface should be SIM_RST 28 O SIM reset automatically. Either protected against ESD 1.8V or 3V. 3V with a TVS diode array. VOLmax=0.36V 2. Maximum trace VOHmin=

length is 200mm from 0.9*SIM_VDD the module pad to SIM card holder. 1.8V:

VOLmax=

0.2*SIM_VDD VOHmin=

0.9*SIM_VDD SIM_ DATA 29 I/

O SIM data 3V VOLmax=0.4V VOHmin=

SIM_VDD-0.4V 1.8V:

VOLmax=

0.15*SIM_VDD VOHmin=

SIM1_VDD-0.4V 3V VOLmax=0.4V VOHmin=

0.9*SIM_VDD 1.8V:

VOLmax=

0.12*SIM_VDD SIM_CLK 30 O SIM clock M35_HD_V1.0 - 24 -

QuectelConfidential M35 Hardware Design SIM_GND 31 RF interface PIN NAME PIN NO. RF_ANT 39 I/

O I/

O VOHmin=

SIM ground 0.9*SIM_VDD DESCRIPTION DC COMMENT RF antenna pad Impedance of 50 CHARACTERISTICS M35_HD_V1.0 - 25 -

QuectelConfidential M35 Hardware Design 3.2. Operating modes The table below briefly summarizes the various operating modes in the following chapters. Table 7: Overview of operating modes Mode Function Normal operation GSM/GPRS The module will automatically go into SLEEP mode if SLEEP DTR is set to high level and there is no interrupt (such as GPIO interrupt or data on UART port). In this case, the current consumption of module will reduce to the minimal level. During SLEEP mode, the module can still receive paging message and SMS from the system normally. GSM IDLE Software is active. The module has registered to the GSM network, and the module is ready to send and receive GSM data. GSM TALK GSM connection is ongoing. In this mode, the power consumption is decided by the configuration of Power Control Level (PCL), dynamic DTX control and the working RF band. GPRS IDLE The module is not registered to GPRS network. The module is not reachable through GPRS channel. GPRS The module is registered to GPRS network, but no GPRS STANDBY PDP context is active. The SGSN knows the Routing Area where the module is located at. GPRS The PDP context is active, but no data transfer is going on. READY The module is ready to receive or send GPRS data. The SGSN knows the cell where the module is located at. GPRS DATA There is GPRS data in transfer. In this mode, power consumption is decided by the PCL, working RF band and GPRS multi-slot configuration. POWER DOWN Normal shutdown by sending the AT+QPOWD=1 command, using the PWRKEY or the EMERG_OFF1) pin. The power management ASIC disconnects the power supply from the base band part of the module, and only the power supply for the RTC is remained. Software is not active. The UART interfaces are not accessible. Operating voltage (connected to VBAT) remains applied. Minimum AT+CFUN command can set the module to a minimum functionality functionality mode without removing the power supply. In this case, the RF part of the mode (without module will not work or the SIM card will not be accessible, or both RF part removing power and SIM card will be disabled, but the UART port is still accessible. The supply) power consumption in this case is very low. M35_HD_V1.0 - 26 -

QuectelConfidential M35 Hardware Design 1) Use the EMERG_OFF pin only while failing to turn off the module by the command AT+QPOWD=1 and the PWRKEY pin. Please refer to Section 3.4.2.2. 3.3. Power supply 3.3.1. Feature of GSM power The unit of GSM transmit in the wireless path is pulse string which is constructed by GSMK bit string and we call it burst. The period of burst is 4.16ms and the last time of burst is 577us. The burst current will reach 1.6A while idle current is as low as tens of milliampere. This sudden change of current will produce large ripple of VBAT or pull the VBAT down to 3.3V, while the module will shut down when VBAT drops to 3.3V. Due to these features, the power design for the module is crucial. The following figure is the VBAT voltage and current ripple at the maximum power transmitting phase, the test condition is VBAT=4.0V, VBAT maximum output current =2A, C1=100F tantalum capacitor (ESR=0.7) and C2=1F. Figure 3: Ripple in supply voltage during transmitting burst 3.3.2. Minimize supply voltage drop The power supply of the module is from a single voltage source of VBAT= 3.3V~4.6V. The GSM transmitting burst can cause obvious voltage drop at the supply voltage thus the power supply must be carefully designed and is capable of providing sufficient current up to 2A. For the VBAT input, a bypass capacitor of about 100F with low ESR is recommended. Multi-layer ceramic chip

(MLCC) capacitor can provide the best combination of low ESR but small size may not be economical. A lower cost choice could be a 100F tantalum capacitor with low ESR. A small M35_HD_V1.0 - 27 -

Max:400mVBurst:1.6A4.615ms577usIBATVBATQuectelConfidential M35 Hardware Design

(0.1F to 1F) ceramic capacitor should be in parallel with the 100F capacitor, which is illustrated in Figure 4. The capacitors should be placed close to the M35 VBAT pins. The PCB traces from the VBAT pads to the power source must be wide enough to ensure that there is not too much voltage drop occurring in the transmitting burst mode. The width of trace should be no less than 2mm and the principle of the VBAT trace is the longer, the wider. The VBAT voltage drop can be measured by oscilloscope. C1=100uF, C2=0.1uF~1uF Figure 4: Reference circuit of the VBAT input 3.3.3. Reference power design for the module The power design for the module is very important and the circuit design of the power supply for the module largely depends on the power source. Figure 5 shows a reference design of +5V input power source. The part number of this LDO IC is MIC29302WU. The designed output for the power supply is 4.16V and the maximum load current is 3A, in order to prevent outputting abnormal voltage, a zener voltage regulator is employed at the point of the output nearby the pin of VBAT. Some elements have to be taken into account in the component select, such as reserve zener voltage is recommend 5.1V and the total dissipation is more than 1Watt. Figure 5: Reference circuit of the source power supply input M35_HD_V1.0 - 28 -

C2C1VBAT+C1100uFC2MIC29032U1INOUTENGNDADJ24135DC_INVBAT100nFC3100uFC4100nFC5C633pFR110pFD1120K51KR25.1VQuectelConfidential M35 Hardware Design 3.3.4. Monitor power supply To monitor the supply voltage, the AT+CBC command can be used which includes three parameters: charging status, remaining battery capacity and voltage value (in mV). It returns the 0-100 percent of battery capacity and actual value measured between VBAT and GND. The voltage is automatically measured in period of 5s. The displayed voltage (in mV) is averaged over the last measuring period before the AT+CBC command is executed. For details, please refer to document [1]. 3.4. Power on and down scenarios 3.4.1. Power on The module can be turned on by PWRKEY pin. The module is set to autobauding mode (AT+IPR=0) in default configuration. In the autobauding mode, the URC RDY after powering on is not sent to host controller. When the module receives AT command, it will be powered on after a delay of 2 or 3 seconds. Host controller should firstly send an AT or at string in order that the module can detect baud rate of host controller, and it should send the second or the third AT or at string until receiving OK string from module. Then an AT+IPR=x;&W should be sent to set a fixed baud rate for module and save the configuration to flash memory of module. After these configurations, the URC RDY would be received from the UART Port of module every time when the module is powered on. Refer to section AT+IPR in document [1]. The hardware flow control is disabled in default configuration. In the simple UART port which means that only TXD, RXD, GND of the module is connected to host. CTS is pulled down internally. In this condition, the module can transmit and receive data freely. On the other side, if RTS, CTS are connected to the host together with TXD, RXD, GND, whether or not to transmit and receive data depends on the level of RTS and CTS. Then whenever hardware flow is present or not, the URC RDY is sent to host controller in the fixed band rate. 3.4.1.1. Power on the module using the PWRKEY pin Customers application can turn on the module by driving the pin PWRKEY to a low level voltage and after STATUS pin outputs a high level, PWRKEY pin can be released. Customer may monitor the level of the STATUS pin to judge whether the module is power-on or not. An open collector driver circuit is suggested to control the PWRKEY. A simple reference circuit is illustrated in Figure 6. M35_HD_V1.0 - 29 -

QuectelConfidential M35 Hardware Design Figure 6: Turn on the module using driving circuit The other way to control the PWRKEY is using a button directly. A TVS component is indispensable to be placed nearby the button for ESD protection. When pressing the key, electrostatic strike may generate from finger. A reference circuit is showed in Figure 7. Figure 7: Turn on the module using keystroke The power-on scenarios is illustrated as the following figure. M35_HD_V1.0 - 30 -

Turn on pulsePWRKEY4.7K47KS1PWRKEYTVS1Close to S1QuectelConfidential M35 Hardware Design Figure 8: Timing of turning on system Make sure that VBAT is stable before pulling down PWRKEY pin. The time between them is recommended 30ms. Note: Customer can monitor the voltage level of the STATUS pin to judge whether the module is power-on. After the STATUS pin goes to high level, PWRKEY can be released. If the STATUS pin is ignored, pull the PWRKEY pin to low level for more than 1 second to turn on the module. 3.4.2. Power down The following procedures can be used to turn off the module:

Normal power down procedure: Turn off module using the PWRKEY pin Normal power down procedure: Turn off module using command AT+QPOWD Over-voltage or under-voltage automatic shutdown: Take effect when over-voltage or under-voltage is detected Emergent power down procedure: Turn off module using the EMERG_OFF pin Emergent power down procedure: Turn off module using command AT+QPOWD 3.4.2.1. Power down module using the PWRKEY pin Customers application can turn off the module by driving the PWRKEY to a low level voltage for certain time. The power-down scenarios is illustrated in Figure 9. M35_HD_V1.0 - 31 -

VDD_EXTOUTPUTVIL<0.1*VBATVBATPWRKEY(INPUT)EMERG_OFFINPUT54ms250msSTATUSOUTPUT800ms1>1sVIH > 0.1*VBATQuectelConfidential M35 Hardware Design The power-down procedure causes the module to log off from the network and allows the software to save important data before completely disconnecting the power supply, thus it is a safe way. Before the completion of the power-down procedure, the module sends out the result code shown as below:

NORMAL POWER DOWN Note: This result code does not appear when autobauding is active and DTE and DCE are not correctly synchronized after start-up. The module is recommended to set a fixed baud rate. After that moment, no further AT commands can be executed. Then the module enters the POWER DOWN mode, only the RTC is still active. The POWER DOWN mode can also be indicated by the STATUS pin, which is a low level voltage in this mode. Figure 9: Timing of turning off the module M35_HD_V1.0 - 32 -

PWRKEYINPUTSTATUSOUTPUT1s > Pulldown > 0.6sLogout net about 2s to 12sVDD_EXTOUTPUTEMERG_OFFOUTPUTVBATOUTPUT160usQuectelConfidential M35 Hardware Design 3.4.2.2. Power down the module using AT command Customers application can turn off the module via AT command AT+QPOWD=1. This command will let the module to log off from the network and allow the software to save important data before completely disconnecting the power supply, thus it is a safe way. Before the completion of the power-down procedure the module sends out the result code shown as below:

NORMAL POWER DOWN After that moment, no further AT commands can be executed. And then the module enters the POWER DOWN mode, only the RTC is still active. The POWER DOWN mode can also be indicated by STATUS pin, which is a low level voltage in this mode. Please refer to document [1] for details about the AT command AT+QPOWD. 3.4.2.3. Over-voltage or under-voltage automatic shutdown The module will constantly monitor the voltage applied on the VBAT, if the voltage is 3.5V, the following URC will be presented:

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

OVER_VOLTAGE WARNING The uncritical voltage range is 3.3V to 4.6V. If the voltage is > 4.6V or <3.3V, the module would automatically shutdown itself. If the voltage is <3.3V, the following URC will be presented:

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

OVER_VOLTAGE POWER DOWN Note: These result codes dont appear when autobauding is active and DTE and DCE are not correctly synchronized after start-up. The module is recommended to set to a fixed baud rate. After that moment, no further AT commands can be executed. The module logs off from network and enters POWER DOWN mode, and only RTC is still active. The POWER DOWN mode can also be indicated by the pin STATUS, which is a low level voltage in this mode. M35_HD_V1.0 - 33 -

QuectelConfidential M35 Hardware Design 3.4.2.4. Emergency shutdown using EMERG_OFF pin The module can be shut down by driving the pin EMERG_OFF to a low level voltage over 20ms and then releasing it. The EMERG_OFF line can be driven by an Open Drain / Collector driver or a button. The circuit is illustrated as the following figures. Figure 10: Reference circuit for EMERG_OFF by using driving circuit Figure 11: Reference circuit for EMERG_OFF by using button 3.4.2.5. Emergency shutdown using AT command Using an AT command AT+QPOWD=0 can achieve emergency shutdown of the module. In this situation, No URC returns back to the host no matter in the fixed band rate or auto band rate. Be cautious to use the pin EMERG_OFF. It should only be used under emergent situation. For instance, if the module is unresponsive or abnormal, the pin EMERG_OFF could be used to shut down the system. Although turning off the module by EMERG_OFF is fully tested and nothing wrong detected, this operation is still a big risk as it could cause destroying of the code or data area of the NOR flash memory in the module. Therefore, it is recommended that PWRKEY or AT command should always be the preferential way to turn off the system. M35_HD_V1.0 - 34 -

Emergency shutdown pulseEMERG_OFF4.7K47KS1EMERG_OFFTVS1Close to S1QuectelConfidential M35 Hardware Design 3.4.3. Restart 3.4.3.1. Restart the module using the PWRKEY pin Customers application can restart the module by driving the PWRKEY to a low level voltage for certain time, which is similar to the way of turning on module. Before restarting the module, at least 500ms should be delayed after detecting the low level of STATUS. The restart timing is illustrated as the following figure. Figure 12: Timing of restarting system The module can also be restarted by the PWRKEY after emergency shutdown. Figure 13: Timing of restarting system after emergency shutdown 3.4.3.2. Restart the module using AT command Using an AT command AT+QPOWD=2 can achieve restart of the module. Please refer to document [1] for the details. M35_HD_V1.0 - 35 -

STATUSOUTPUTHPWRKEYINPUTDelay > 0.5sTurn offPull down the PWRKEY to turn on the moduleRestartPWRKEYINPUTPulldown>20msDelay>2sEMERG_OFFINPUTSTATUSOUTPUT6usQuectelConfidential M35 Hardware Design 3.5. Power saving Upon system requirement, there are several actions to drive the module to enter low current consumption status. For example, AT+CFUN can be used to set module into minimum functionality mode and DTR hardware interface signal can be used to lead system to SLEEP mode. 3.5.1. Minimum functionality mode Minimum functionality mode reduces the functionality of the module to minimum level, thus minimize the current consumption when the slow clocking mode is activated at the same time. This mode is set with the AT+CFUN command which provides the choice of the functionality levels <fun>=014. 0: minimum functionality 1: full functionality (default) 4: disable both transmitting and receiving of RF part If the module is set to minimum functionality by AT+CFUN=0, the RF function and SIM card function would be disabled. In this case, the UART port is still accessible, but all AT commands correlative with RF function or SIM card function will not be accessible. If the module has been set by AT+CFUN=4, the RF function will be disabled, but the UART port is still active. In this case, all AT commands correlative with RF function will not be accessible. After the module is set by AT+CFUN=0 or AT+CFUN=4, it can return to full functionality by AT+CFUN=1. For detailed information about AT+CFUN, please refer to document [1]. 3.5.2. Sleep mode The SLEEP mode is disabled in default software configuration. Customers application can enable this mode by AT+QSCLK=1. On the other hand, the default setting is AT+QSCLK=0 and in this mode, the module cannot enter SLEEP mode. When AT+QSCLK=1 is sent to the module, customers application can control the module to enter or exit from the SLEEP mode through pin DTR. When DTR is set to high level, and there is no on-air or hardware interrupt such as GPIO interrupt or data on UART port, the module will enter SLEEP mode automatically. In this mode, the module can still receive voice, SMS or GPRS paging from network but the UART port is not accessible. M35_HD_V1.0 - 36 -

QuectelConfidential M35 Hardware Design 3.5.3. Wake up the module from SLEEP mode When the module is in the SLEEP mode, the following methods can wake up the module. If the DTR Pin is set low, it would wake up the module from the SLEEP mode. The UART port will be active within 20ms after DTR is changed to low level. Receiving a voice or data call from network wakes up module. Receiving an SMS from network wakes up module. Note: DTR pin should be held low level during communication between the module and DTE. 3.6. Summary of state transitions Table 8: Summary of state transition Current mode Next mode Power down Normal mode Sleep mode Power down Use PWRKEY Normal mode AT+QPOWD, use Use AT command PWRKEY pin, or use EMERG_OFF pin AT+QSCLK=1 and pull DTR up Sleep mode Use PWRKEY pin, or Pull DTR down or use EMERG_OFF pin incoming call or SMS or GPRS 3.7. RTC backup The RTC (Real Time Clock) can be supplied by an external capacitor or battery (rechargeable or non-chargeable) through the pin VRTC. A 1.5 K resistor has been integrated in the module for current limiting. A coin-cell battery or a super-cap can be used to backup power supply for RTC. The following figures show various sample circuits for RTC backup. M35_HD_V1.0 - 37 -

QuectelConfidential M35 Hardware Design Figure 14: RTC supply from non-chargeable battery Figure 15: RTC supply from rechargeable battery Figure 16: RTC supply from capacitor Coin-type rechargeable capacitor such as XH414H-IV01E from Seiko can be used. M35_HD_V1.0 - 38 -

RTCCore1.5KMODULEVRTCNon-chargeableBackup BatteryRTCCore1.5KMODULEVRTCRechargeableBackup BatteryRTCCore1.5KMODULEVRTC Large-capacitance CapacitorQuectelConfidential M35 Hardware Design Figure 17: Seiko XH414H-IV01E Charge Characteristics 3.8. Serial interfaces The module provides two serial ports: UART and Debug Port. The module is designed as a DCE

(Data Communication Equipment), following the traditional DCE-DTE (Data Terminal Equipment) connection. Autobauding function supports baud rate from 4800bps to 115200bps. The UART Port:

TXD: Send data to RXD of DTE RXD: Receive data from TXD of DTE RTS: Requests to send CTS: Clear to send DTR: DTE is ready and inform DCE (this pin can wake the module up) RI: Ring indicator (when the call, SMS, data of the module are coming, the module will output signal to inform DTE) DCD: Data carrier detection (the valid of this pin demonstrates the communication link is set up) The module disables hardware flow control in 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]. The Debug Port DBG_TXD: Send data to the COM port of a debugging computer DBG_RXD: Receive data from the COM port of a debugging computer M35_HD_V1.0 - 39 -

QuectelConfidential M35 Hardware Design The logic levels are described in the following table. Table 9: Logic levels of the UART interface Parameter VIL VIH VOL VOH Min 0 Max Unit 0.25*VDD_EXT 0.75*VDD_EXT VDD_EXT +0.3 0 0.15*VDD_EXT 0.85*VDD_EXT VDD_EXT V V V V Table 10: Pin definition of the UART interfaces Interface Name Pin Function 14 15 20 21 22 23 24 25 26 Receive data of the debug port Transmit data of the debug port Data terminal ready Receive data of the UART port Transmit data of the UART port Clear to send Request to send Data carrier detection Ring indicator Debug Port DBG_RXD DBG_TXD DTR RXD TXD CTS RTS DCD RI UART Port 3.8.1. UART Port 3.8.1.1 The features of UART Port. Seven lines on UART interface Contain data lines TXD and RXD, hardware flow control lines RTS and CTS, other control lines DTR, DCD and RI Used for AT command, GPRS data, CSD FAX, etc. Multiplexing function is supported on the UART Port. So far only the basic mode of multiplexing is available. Support the communication baud rates as the following:

300,600,1200,2400,4800,9600,14400,19200,28800,38400,57600,115200. The default setting is autobauding mode. Support the following baud rates for autobauding function:

4800, 9600, 19200, 38400, 57600, 115200. The module disables hardware flow control in default, AT command AT+IFC=2,2 is used to enable hardware flow control After setting a fixed baud rate or autobauding, please send AT string at that rate. The UART port is ready when it responds OK. M35_HD_V1.0 - 40 -

QuectelConfidential M35 Hardware Design 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 in default. To take advantage of the autobauding mode, special attention should be paid according to the following requirements:

Synchronization between DTE and DCE:

When DCE (the module) powers on and the autobauding is enabled, it is recommended to wait 2 to 3 seconds before sending the first AT character. After receiving the OK response, DTE and DCE are correctly synchronized. If the host controller needs URC in the mode of autobauding, it must be synchronized firstly. Otherwise the URC will be discarded. Restrictions on autobauding operation The UART port has to be operated at 8 data bits, no parity and 1 stop bit (factory setting). The A/ and a/ commands cant be used. Only the strings AT or at can be detected (neither At nor aT). The Unsolicited Result Codes like "RDY", "+CFUN: 1" and "+CPIN: READY will not be indicated when the module is turned on with autobauding enabled and not be synchronized. Any other Unsolicited Result Codes will be sent at the previous baud rate before the module detects the new baud rate by receiving the first AT or at string. The DTE may receive unknown characters after switching to new baud rate. It is not recommended to switch to autobauding from a fixed baud rate. If autobauding is active it is not recommended to switch to multiplex mode Note: To assure reliable communication and avoid any problems caused by undetermined baud rate between DCE and DTE, it is strongly recommended to configure a fixed baud rate and save it instead of using autobauding after start-up. For more details, please refer to Section AT+IPR in document [1]. 3.8.1.2. The connection of UART The connection between module and host via UART port is very flexible. Three connection styles are illustrated as below. UART Port connection is shown as below when it is applied in modulation-demodulation. M35_HD_V1.0 - 41 -

QuectelConfidential M35 Hardware Design Figure 18: Connection of all functional UART port Three lines connection is shown as below. Figure 19: Connection of three lines UART port UART Port with hardware flow control is shown as below. This connection will enhance the reliability of the mass data communication. M35_HD_V1.0 - 42 -

TXDRXDRTSCTSDTRDCDRITXDRXDRTSCTSDTRDCDRIModule (DCE)PC (DTE)UART portUART PortGNDGNDHost(DTE) Controller TXD RXD GND Module(DCE)TXDRXDGNDUART PortRTS0RQuectelConfidential M35 Hardware Design Figure 20: Connection of UART port associated hardware flow control 3.8.1.3. Software upgrade The TXD, RXD can be used to upgrade software. The PWRKEY pin must be pulled down before the software upgrades. Please refer to the following figures for software upgrade. Figure 21: Connection of software upgrade M35_HD_V1.0 - 43 -

Host(DTE) Controller Module(DCE)RTSCTSRTSGNDGNDRXDTXDUART PortCTSRXDTXD IO Connector TXDRXDGNDPWRKEY Module (DCE ) UART Port TXD RXD GND PWRKEYQuectelConfidential M35 Hardware Design 3.8.2. Debug Port Debug Port Two lines: DBG_TXD and DBG_RXD It outputs log information automatically. Debug Port is only used for software debugging and its baud rate must be configured as 460800bps. Figure 22: Connection of software debug 3.8.3. UART Application The reference design of 3.3V level match is shown as below. 1K and 5.6K resistors among the following diagram are used to decrease the output voltage of MCU/ARM. M35_HD_V1.0 - 44 -

Debug Computer TXD RXD GND Module(DCE) Debug port DBG_TXD DBG_RXD GNDQuectelConfidential M35 Hardware Design Figure 23: 3.3V level match circuit Note: 5.6K resistors among the above diagram need to be changed to 15K resistors for 3V system. M35_HD_V1.0 - 45 -

MCU/ARMMODULE/TXD/RXDTXDRXDRTSCTSDTRRI/RTS/CTSGPIOEINTvoltage level: 3.3VGPIODCD1K1K1K1K1K5K65K65K61K1KQuectelConfidential M35 Hardware Design The reference design of 5V level match is shown as below. The construction of dotted line can refer to the construction of solid line. Please pay attention to direction of connection. Input dotted line of module should refer to input solid line of the module. Output dotted line of module should refer to output solid line of the module. Figure 24: 5V level match circuit M35_HD_V1.0 - 46 -

MCU/ARM/TXD/RXD1KVDD_EXT4.7kVCC_MCU4.7k4.7k4.7kVDD_EXTTXDRXDRTSCTSDTRRI/RTS/CTSvoltage level: 5VGNDVBATGPIOSTATUSMODULEGPIOEINTVCC_MCUQuectelConfidential M35 Hardware Design The following picture is an example of connection between module and PC. A RS_232 level shifter IC or circuit must be inserted between module and PC, since these three UART ports dont support the RS_232 level, while support the CMOS level only. Figure 25: RS232 level match circuit M35_HD_V1.0 - 47 -

98765432115148911125761042622713182021161719222324312528GNDTO PC serial portSP32383VGNDGNDT5OUT/SHUTDOWNV+GNDV-VCCT4OUTT2OUTT3OUTT1OUTR3INR2INR1IN/STATUS3VONLINER1OUTR2OUTR3OUT/R1OUTGNDT5INT4INT3INT2INT1INC2+C2-C1-C1+MODULERXDDTRRTSRICTSTXDDCDQuectelConfidential M35 Hardware Design 3.9. Audio interfaces The module provides two analogy input channels and three analogy output channels. Table 11: Pin definition of Audio interface Interface AIN1/AOUT1 AIN2/AOUT2 Name MIC1P MIC1N SPK1N SPK1P MIC2P MIC2N AGND LOUDSPKP LOUDSPKN Pin Function 4 5 6 7 2 3 1 9 8 Channel one of Microphone positive input Channel one of Microphone negative input Channel one of Audio negative output Channel one of Audio positive output Channel two of Microphone positive input Channel two of Microphone negative input Cooperate with LOUDSPKP Channel two of Audio positive output Channel two of Audio negative output AIN1 and AIN2 can be used for input of microphone and line. An electret microphone is usually used. AIN1 and AIN2 are both differential input channels. AOUT1 is used for output of the receiver and speaker. This channel is typically used for a receiver built into a handset. AOUT1 channel is a differential channel. It only supports voice path. If it is used as a speaker, an amplifier should be employed. AOUT2 is used for loud speaker output as it is embedded an amplifier of class AB whose maximum drive power is 800mW. AOUT2 is a differential channel. Immediately playing Melody or Midi ring tone for incoming call is available in AOUT2. AOUT2 also can be used for output of earphone, which can be used as a single-ended channel. LOUDSPKP and AGND can establish a pseudo differential mode. These two audio channels can be swapped by AT+QAUDCH command. For more details, please refer to document [1]. Use AT command AT+QAUDCH to select audio channel:

0--AIN1/AOUT1, the default value is 0. 2--AIN2/AOUT2 For each channel, customer can use AT+QMIC to adjust the input gain level of microphone. Customer can also use AT+CLVL to adjust the output gain level of receiver and speaker. AT+QECHO is used to set the parameters for echo cancellation control. AT+QSIDET is used to set the side-tone gain level. For more details, please refer to document [1]. M35_HD_V1.0 - 48 -

QuectelConfidential M35 Hardware Design Table 12: AOUT2 output characteristics Item RMS power Condition min 8ohm load VBAT=4.3V THD+N=1%

8ohm load VBAT=3.7V THD+N=1%

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

0 type 800 700 500 3 max 18 unit mW mW mW dB dB Gain adjustment range Gain adjustment steps 3.9.1. Decrease TDD noise and other noise The 33pF capacitor is applied for filtering out 900MHz RF interference when the module is transmitting at GSM900MHz. Without placing this capacitor, TDD noise could be heard. Moreover, the 10pF capacitor here is for filtering out 1800MHz RF interference. However, the resonant frequency point of a capacitor largely depends on the material and production technique. Therefore, customer would have to discuss with its capacitor vendor to choose the most suitable capacitor for filtering out GSM850MHz, GSM900MHz, DCS1800MHz and PCS1900MHz separately. The severity degree of the RF interference in the voice channel during GSM transmitting period largely depends on the application design. In some cases, GSM900 TDD noise is more severe;

while in other cases, DCS1800 TDD noise is more obvious. Therefore, customer can have a choice based on test results. Sometimes, even no RF filtering capacitor is required. The capacitor which is used for filtering out RF noise should be close to RJ11 or other audio interfaces. Audio alignment should be as short as possible. In order to decrease radio or other signal interference, the position of RF antenna should be kept away from audio interface and audio alignment. Power alignment and audio alignment should not be parallel, and power alignment should be far away from audio alignment. The differential audio traces have to be placed according to the differential signal layout rule. M35_HD_V1.0 - 49 -

QuectelConfidential M35 Hardware Design 3.9.2. Microphone interfaces design AIN1/IN2 channels come with internal bias supply for external electret microphone. A reference circuit is shown in Figure 26. Figure 26: Microphone interface design of AIN1&AIN2 3.9.3. Receiver interface design Figure 27: Receiver interface design of AOUT1 M35_HD_V1.0 - 50 -

MICxPDifferential layoutModule10pF33pF33pF33pFGNDGNDElectret MicrophoneGNDGND10pF10pFGNDGNDESD ANTIESDANTI33pF10pFClose to ModuleMICxNGNDGNDGNDGND10pF33pF33pF10pFClose to MICSPK1PSPK1NDifferential layout10pF10pF33pF33pF33pFGNDGND10pFESD ANTIESD ANTIModuleClose to ReceiverGNDGNDGNDGNDQuectelConfidential M35 Hardware Design 3.9.4. Earphone interface design Figure 28: Earphone interface design 3.9.5. Loud speaker interface design Figure 29: Loud speaker interface design M35_HD_V1.0 - 51 -

1243MIC2P22uF68R33pFGNDGNDAGNDClose to Socket33pFAGND33pF10pFGNDGNDGNDGNDAGNDModule4.7uFLOUDSPKPClose to ModuleGNDGNDGNDGND10pF33pF33pF10pFDifferential layout33pF10pFMIC2N0RAmphenol9001-8905-050LOUDSPKNDifferential layout10pF10pF33pF33pFGNDGNDESD ANTIESD ANTI0R0RLOUDSPKPGNDGNDGNDGND10pF33pF8 ohmClose to SpeakerModuleQuectelConfidential M35 Hardware Design 3.9.6. Audio characteristics Table 13: Typical electret microphone characteristics Typ 1.5 2.2 Max 2.0 500 Unit V uA k Ohm Min 1.2 200 Parameter Working Voltage Working Current External Microphone Load Resistance Table 14: Typical speaker characteristics Parameter Normal Output

(AOUT1) Single Ended Load Resistance Min 28 Typ 32 Max Ref level 0 2.4 Differential Load 28 32 Auxiliary Output

(AOUT2) Single Ended Resistance Ref level Load Resistance Ref level Load Differential Resistance Ref level 0 0 0 8 8 3.10. SIM card interface 3.10.1. SIM card application Unit Ohm Vpp Ohm Vpp Load 4.8 Resistance VBAT Vpp Load Resistance 2*VBAT Vpp The SIM interface supports the functionality of the GSM Phase 1 specification and also supports the functionality of the new GSM Phase 2+ specification for FAST 64 kbps SIM card, which is intended for use with a SIM application Tool-kit. M35_HD_V1.0 - 52 -

QuectelConfidential M35 Hardware Design The SIM interface is powered from an internal regulator in the module. Both 1.8V and 3.0V SIM Cards are supported. Table 15: Pin definition of the SIM interface Name SIM_VDD SIM_RST SIM_DATA SIM_CLK SIM_GND Pin 27 28 29 30 31 Function Supply power for SIM Card. Automatic detection of SIM card voltage. 3.0V10% and 1.8V10%. Maximum supply current is around 10mA. SIM Card reset SIM Card data I/O SIM Card clock SIM Card ground The reference circuit using a 6-pin SIM card holder is illustrated as the following figure. Figure 30: Reference circuit of the 6 pins SIM card The following design rules can optimize the SIM interface performance and protect the SIM card effectively. The rules should be taken into account in designing the circuit. Place the SIM card holder close to module as close as possible. Ensure the trace length of SIM signals keeps less than 200mm. Keep the SIM signals far away from VBAT power and RF trace. The width of SIM_VDD and SIM_GND trace is not less than 0.5mm. Place a bypass capacitor close to SIM card power pin. The value of capacitor is less than 1uF. M35_HD_V1.0 - 53 -

Module22R22R22RC707 10M006 512 2SIM CARDGNDSIM_VDDSIM_RSTSIM_CLKSIM_DATASIM_GND100nFVCCRSTCLKGNDVPPIOQuectelConfidential M35 Hardware Design To avoid possible cross-talk from the SIM_CLK signal to the SIM_DATA signal be careful that both traces are not placed closely next to each other. The traces of SIM_CLK, SIM_DATA and SIM_RST are recommended to be around with GND independently. All signals of SIM interface should be protected against ESD with a TVS diode array. It is recommended to add TVS diode such as WILL (http://www.willsemi.com) ESDA6V8AV6. The parasitic capacitance of TVS diode is less than 50pF. The 22 resistors should be added in series between the module and the SIM card so as to suppress the EMI spurious transmission and enhance the ESD protection. All the peripheral components are recommended to place near the SIM card holder. 3.10.2. 6 Pin SIM cassette For 6-pin SIM card holder, it is recommended to use Amphenol C707 10M006 512 2. Please visit http://www.amphenol.com for more information. Figure 31: Amphenol C707 10M006 512 2 SIM card holder Table 16: Pin description of Amphenol SIM card holder Name SIM_VDD SIM_RST SIM_CLK GND Pin C1 C2 C3 C5 Function SIM Card Power Supply SIM Card Reset SIM Card Clock Ground M35_HD_V1.0 - 54 -

QuectelConfidential M35 Hardware Design VPP C6 SIM_DATA C7 Not Connect SIM Card data I/O 3.12. Behaviors of the RI Table 17: Behaviors of the RI State Standby RI respond HIGH Voice calling Change to LOW, then:

(1) Change to HIGH when call is established.

(2) Use ATH to hang up the call, change to HIGH.

(3) Calling part hangs up, change to HIGH first, and change to LOW for 120ms indicating NO CARRIER as an URC, then change to HIGH again. Data calling

(4) Change to HIGH when SMS is received. Change to LOW, then

(1) Change to HIGH when data connection is established.

(2) Use ATH to hang up the data calling, change to HIGH.

(3) Calling part hangs up, change to HIGH first, and change to LOW for 120ms indicating NO CARRIER as an URC, then change to HIGH again.

(4) Change to HIGH when SMS is received. SMS When a new SMS comes, the RI changes to LOW and holds low level for about 120 ms, then changes to HIGH. URC Certain URCs can trigger 120ms low level on RI. For more details, please refer to the document [10]. If the module is used as a caller, the RI would maintain high except the URC or SMS is received. On the other hand, when it is used as a receiver, the timing of the RI is shown below. Figure 32: RI behavior of voice calling as a receiver M35_HD_V1.0 - 55 -

RIIdleRingOff-hook by ATA. On-hook by ATH. SMS received. HIGHLOWQuectelConfidential M35 Hardware Design Figure 33: RI behavior of data calling as a receiver Figure 34: RI behavior as a caller Figure 35: RI behavior of URC or SMS received M35_HD_V1.0 - 56 -

RIIdleRingData calling establish. On-hook by ATH. SMS receivedHIGHLOWRIIdleCallingOn-hookTalkingHIGHLOWIdleRIIdle or talking URC or SMS Received HIGHLOW120msQuectelConfidential M35 Hardware Design 3.13. Network status indication The NETLIGHT signal can be used to drive a network status indication LED. The working state of this pin is listed in Table 18. Table 18: Working state of the NETLIGHT State Off Module function The module is not running. 64ms On/ 800ms Off The module is not synchronized with network. 64ms On/ 2000ms Off The module is synchronized with network. 64ms On/ 600ms Off GPRS data transfer is ongoing. A reference circuit is shown in Figure 36. Figure 36: Reference circuit of the NETLIGHT 3.14. Operating status indication The STATUS pin is set as an output pin and can be used to judge whether module is power-on. In customers design, this pin can be connected to a GPIO of DTE or be used to drive an LED in order to judge the modules operation status. A reference circuit is shown in Figure 37. Table 19: Pin definition of the STATUS Name STATUS Pin 12 Function Indication of module operating status M35_HD_V1.0 - 57 -

Module300R4.7K47KVBATNETLIGHTQuectelConfidential M35 Hardware Design Figure 37: Reference circuit of the STATUS M35_HD_V1.0 - 58 -

Module300R4.7K47KVBATSTATUSQuectelConfidential M35 Hardware Design 4. Antenna interface The Pin 39 is the RF antenna pad. The RF interface has an impedance of 50. Table 20: Pin definition of the Antenna interface Name Pin Function GND GND RF_ANT GND 37 38 39 40 ground ground RF antenna pad ground 4.1. RF reference design The RF external circuit is recommended as below:

Figure 38: Reference circuit of RF M35 provides an RF antenna PAD for customers antenna connection. The RF trace in host PCB connected to the module RF antenna pad should be micro-strip line or other types of RF trace, whose characteristic impendence should be close to 50. M35 comes with grounding pads which are next to the antenna pad in order to give a better grounding. To minimize the loss on the RF trace and RF cable, take design into account carefully. It is recommended that the insertion loss should meet the following requirements:

GSM850/EGSM900 is <1dB. DCS1800/PCS1900 is <1.5dB. M35_HD_V1.0 - 59 -

RF_ANT0RMODULENMNMQuectelConfidential M35 Hardware Design 4.2. RF output power Table 21: The module conducted RF output power Frequency GSM850 EGSM900 DCS1800 PCS1900 Max 33dBm 2dB 33dBm 2dB 30dBm 2dB 30dBm 2dB Min 5dBm5dB 5dBm5dB 0dBm5dB 0dBm5dB Note: In GPRS 4 slots TX mode, the max output power is reduced by 2.5dB. This design conforms to the GSM specification as described in section 13.16 of 3GPP TS 51.010-1. 4.3. RF receiving sensitivity Table 22: The module conducted RF receiving sensitivity Frequency GSM850 EGSM900 DCS1800 PCS1900 Receive sensitivity

< -108.5dBm

< -108.5dBm

< -108.5dBm

< -108.5dBm 4.4. Operating frequencies Table 23: The module operating frequencies Frequency Receive Transmit GSM850 869~894MHz 824~849MHz ARFCH 128~251 EGSM900 925~960MHz 880~915MHz 0~124, 975~1023 DCS1800 1805~1880MHz 1710~1785MHz PCS1900 1930~1990MHz 1850~1910MHz 512~885 512~810 4.5. RF cable soldering Soldering the RF cable to RF pad of module correctly will reduce the loss on the path of RF, refer to the following example of RF soldering. M35_HD_V1.0 - 60 -

QuectelConfidential M35 Hardware Design Figure 39: RF soldering sample M35_HD_V1.0 - 61 -

QuectelConfidential M35 Hardware Design 5. Electrical, reliability and radio characteristics 5.1. Absolute maximum ratings Absolute maximum ratings for power supply and voltage on digital and analog pins of module are listed in the following table:

Table 24: Absolute maximum ratings Parameter VBAT Peak current of power supply Min

-0.3 0 RMS current of power supply (during one TDMA- frame) 0 Voltage at digital pins Voltage at analog pins

-0.3

-0.3 Max

+4.73 2 0.7 3.3 3.0 Voltage at digital/analog pins in POWER DOWN mode

-0.25 0.25 Unit V A A V V V 5.2. Operating temperature The operating temperature is listed in the following table:

Table 25: Operating temperature Parameter Normal Temperature Restricted Operation1) Storage Temperature Min

-35 Typ 25

-40 ~ -35

-45 Max Unit 80 80 ~ 85

+90 1) When the module works above temperature range, the deviations from the GSM specification may occur. For example, the frequency error or the phase error will be increased. 5.3. Power supply ratings Table 26: The module power supply ratings Parameter Description Conditions Min Typ Max Unit VBAT Supply voltage Voltage must stay within the 3.3 4.0 4.6 V min/max values, including voltage drop, ripple, and spikes. M35_HD_V1.0 - 62 -

QuectelConfidential M35 Hardware Design 400 mV 50 mV 2 mV 30 0.9 13 13 206/214 153/152 1.5 2 uA mA mA mA mA mA A Voltage drop Maximum power control level during on GSM850 and GSM900. transmitting burst Voltage Maximum power control level ripple on GSM850 and GSM900

@ f<200kHz

@ f>200kHz IVBAT Average POWER DOWN mode supply current SLEEP mode @ DRX=5 IDLE mode GSM850/EGSM 900 DCS1800/PCS1900 TALK mode GSM850/EGSM 9001) DCS1800/PCS19002) Peak supply Maximum power control level on GSM850 and GSM900. current

(during transmission slot) 1) Power control level PCL 5 2) Power control level PCL 0 5.4. Current consumption The values of current consumption are shown in Table 27. Table 27: The module current consumption Condition Voice Call GSM850 Current Consumption

@power level #5 <300mA,Typical 206mA

@power level #12,Typical 95mA

@power level #19,Typical 73mA GSM900

@power level #5 <300mA,Typical 214mA

@power level #12,Typical 74mA

@power level #19,Typical 73mA DCS1800

@power level #0 <250mA,Typical 153mA

@power level #7,Typical 82mA M35_HD_V1.0 - 63 -

QuectelConfidential M35 Hardware Design PCS1900

@power level #0 <250mA,Typical 153mA

@power level #15,Typical 69mA

@power level #7,Typical 82mA

@power level #15,Typical 70mA 5.5. Electro-static discharge Although the GSM engine is generally protected against Electrostatic Discharge (ESD), ESD protection precautions should still be emphasized. Proper ESD handling and packaging procedures must be applied throughout the processing, handling and operation of any applications using the module. The measured ESD values of module are shown as the following table:

Table 28: The ESD endurance (Temperature:25,Humidity:45 %) Tested point VBAT,GND RF_ANT TXD, RXD Others Contact discharge Air discharge 5KV 5KV 4KV 0.5KV 10KV 10KV 8KV 1KV M35_HD_V1.0 - 64 -

QuectelConfidential M35 Hardware Design 6. Mechanical dimensions This chapter describes the mechanical dimensions of the module. 6.1. Mechanical dimensions of module Figure 40: M35 top and side dimensionsUnit: mm M35_HD_V1.0 - 65 -

QuectelConfidential M35 Hardware Design Figure 41: M35 bottom dimensionsUnit: mm M35_HD_V1.0 - 66 -

1QuectelConfidential M35 Hardware Design 6.2. Footprint of recommendation Figure 42: Footprint one of recommendationUnit: mm Note 1. The blue pads are used for reserved pins customs can design the PCB decal without them. 2. To maintain the module, keep about 3mm away between the module and other components in host PCB. M35_HD_V1.0 - 67 -

BBAASilksreenSilksreenframe lineframe lineQuectelConfidential M35 Hardware Design 6.3. Top view of the module Figure 43: Top view of the module M35_HD_V1.0 - 68 -

QuectelConfidential M35 Hardware Design 6.4. Bottom view of the module Figure 44: Bottom view of the module M35_HD_V1.0 - 69 -

QuectelConfidential M35 Hardware Design 7. Storage and Manufacturing 7.1. Storage M35 is distributed in vacuum-sealed bag. The restriction of storage condition is shown as below. Shelf life in sealed bag: 12 months at <40 C / 90%RH After this bag is opened, devices that will be subjected to reflow solder or other high temperature process must be:

Mounted within 72 hours at factory conditions of 30 C /60% RH Stored at <10% RH Devices require bake, before mounting, if:

Humidity indicator card is >10% when read 23 C5 C Mounted for more than 72 hours at factory conditions of 30 C /60% RH If baking is required, devices may be baked for 48 hours at 125 C5 C Note: As plastic container cannot be subjected to high temperature, devices must be removed prior to high temperature (125 C) bake. If shorter bake times are desired, please refer to IPC/JEDECJ-STD-033 for bake procedure. M35_HD_V1.0 - 70 -

QuectelConfidential M35 Hardware Design 7.2. Soldering The squeegee should push the paste on the surface of the stencil that makes the paste fill the stencil openings and penetrate to the PCB. The force on the squeegee should be adjusted so as to produce a clean stencil surface on a single pass. To ensure the module soldering quality, the thickness of stencil at the hole of the module pads should be 0.2mm for M35. Figure 45: Paste application Suggest peak reflow temperature is from 235 C to 245 C (for SnAg3.0Cu0.5 alloy). Absolute max reflow temperature is 260 C. To avoid damage to the module when it was repeatedly heated, it is suggested that the module should be mounted after the first panel has been reflowed. The following picture is the actual diagram which we have operated. M35_HD_V1.0 - 71 -

QuectelConfidential M35 Hardware Design Figure 46: Ramp-Soak-Spike reflow profile 7.3. Packaging M35 modules are distributed in trays of 25 pieces each. This is especially suitable for the M35 according to SMT processes requirements. The trays are stored inside a vacuum-sealed bag which is ESD protected. It should not be opened until the devices are ready to be soldered onto the application. Figure 47: Module tray M35_HD_V1.0 - 72 -

Time(s)5010015020025030050100150200250 160 200217070s~120s40s~60sBetween 1~3/SPreheatHeatingCoolingsLiquids Temperature QuectelConfidential M35 Hardware Design Appendix A: GPRS coding schemes Four coding schemes are used in GPRS protocol. The differences between them are shown in Table 29. Table 29: Description of different coding schemes Scheme Code USF Pre-coded Radio BCS Tail Coded Punctured Data rate USF Block bits bits excl.USF and BCS 1/2 2/3 3/4 1 3 3 3 3 3 6 6 12 181 268 312 428 40 16 16 16 4 4 4

-

456 588 676 456 0 132 220

-

CS-1 CS-2 CS-3 CS-4 Radio block structure of CS-1, CS-2 and CS-3 is shown as Figure 48:

rate Kb/s 9.05 13.4 15.6 21.4 Radio Block USF BCS Rate 1/2 convolutional coding Puncturing 456 bits Figure 48: Radio block structure of CS-1, CS-2 and CS-3 Radio block structure of CS-4 is shown as Figure 49:

USF block code Radio Block No coding 456 bits BCS Figure 49: Radio block structure of CS-4 M35_HD_V1.0 - 73 -

QuectelConfidential M35 Hardware Design Appendix B: GPRS multi-slot classes Twenty-nine classes of GPRS multi-slot modes are defined for MS in GPRS specification. Multi-slot classes are product dependant, and determine the maximum achievable data rates in both the uplink and downlink directions. Written as 3+1 or 2+2, the first number indicates the amount of downlink timeslots, while the second number indicates the amount of uplink timeslots. The active slots determine the total number of slots the GPRS device can use simultaneously for both uplink and downlink communications. The description of different multi-slot classes is shown in Table 30. Table 30: GPRS multi-slot classes Multislot class Downlink slots Uplink slots Active slots 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 1 2 2 3 2 3 3 4 3 4 4 4 3 4 5 6 7 8 6 6 6 6 6 8 8 8 8 8 8 1 1 2 1 2 2 3 1 2 2 3 4 3 4 5 6 7 8 2 3 4 4 6 2 3 4 4 6 8 2 3 3 4 4 4 4 5 5 5 5 5 NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA M35_HD_V1.0 - 74 -

QuectelConfidential Shanghai Quectel Wireless Solutions Co., Ltd. Room 501, Building 13, No.99 Tianzhou Road, Shanghai, China 200233 Tel: +86 21 5108 6236 Mail: info@quectel.com