Siemens MD741-1 EGPRS/GSM Router User Manual MC75

Siemens AG EGPRS/GSM Router MC75

Contents

UserMan1 MC75

  Hardware Interface Description MC75 Siemens Cellular Engine   Version: 00.190a DocID: MC75_V00.190a s
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 2 of 91  15.02.2005     Document Name:  MC75 Hardware Interface Description   Version:  00.190a   Date:  February 15, 2005   DocId:  MC75_V00.190a   Status:  Strictly confidential / Draft          General note Product is deemed accepted by Recipient and is provided without interface to Recipient´s products. The Product constitutes pre-release version and code and may be changed substantially before commercial release. The Product is provided on an “as is” basis only and may contain deficiencies or inadequacies. The Product is provided without warranty of any kind, express or implied. To the maximum extent permitted by applicable law, Siemens further disclaims all warranties, including without limitation any implied warranties of merchantability, fitness for a particular purpose and noninfringement of third-party rights. The entire risk arising out of the use or performance of the Product and documentation remains with Recipient. This Product is not intended for use in life support appliances, devices or systems where a malfunction of the product can reasonably be expected to result in personal injury. Applications incorporating the described product must be designed to be in accordance with the technical specifications provided in these guidelines. Failure to comply with any of the required procedures can result in malfunctions or serious discrepancies in results. Furthermore, all safety instructions regarding the use of mobile technical systems, including GSM products, which also apply to cellular phones must be followed. Siemens AG customers using or selling this product for use in any applications do so at their own risk and agree to fully indemnify Siemens for any damages resulting from illegal use or resale. To the maximum extent permitted by applicable law, in no event shall Siemens or its suppliers be liable for any consequential, incidental, direct, indirect, punitive or other damages whatsoever (including, without limitation, damages for loss of business profits, business interruption, loss of business information or data, or other pecuniary loss) arising out the use of or inability to use the Product, even if Siemens has been advised of the possibility of such damages. Subject to change without notice at any time.   Copyright Transmittal, reproduction, dissemination and/or editing of this document as well as utilization of its contents and communication thereof to others without express authorization are prohibited. Offenders will be held liable for payment of damages. All rights created by patent grant or registration of a utility model or design patent are reserved.  Copyright © Siemens AG 2005
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 3 of 91  15.02.2005 Contents  0 Document History .........................................................................................................6 1 Introduction ...................................................................................................................8 1.1 Related Documents ...............................................................................................8 1.2 Terms and Abbreviations.......................................................................................9 1.3 Type Approval......................................................................................................12 1.4 Safety Precautions...............................................................................................14 2 Product Concept .........................................................................................................16 2.1 Key Features at a Glance ....................................................................................16 2.2 MC75 System Overview ......................................................................................19 2.3 Circuit Concept ....................................................................................................20 3 Application Interface...................................................................................................21 3.1 Power Supply.......................................................................................................22 3.1.1 Minimizing Power Losses ......................................................................22 3.1.2 Measuring the Supply Voltage VBATT+ ....................................................23 3.1.3 Monitoring Power Supply by AT Command ...........................................23 3.2 Power Up / Power Down Scenarios.....................................................................24 3.2.1 Turn on MC75 ........................................................................................24 3.2.1.1 Turn on MC75 Using Ignition Line IGT ..................................................24 3.2.1.2 Turn on MC75 Using the VCHARGE Signal ..........................................26 3.2.1.3 Reset MC75 via AT+CFUN Command ..................................................27 3.2.1.4 Reset MC75 in Case of Emergency via EMERG_RST..........................27 3.2.2 Turn off MC75 ........................................................................................28 3.2.2.1 Turn off MC75 Using AT Command.......................................................28 3.2.2.2 Leakage Current in Power Down Mode .................................................29 3.2.3 Automatic Shutdown ..............................................................................30 3.2.3.1 Temperature Dependent Shutdown.......................................................30 3.2.3.2 Temperature Control during Emergency call .........................................31 3.2.3.3 Undervoltage Shutdown if Battery NTC is Present ................................31 3.2.3.4 Undervoltage Shutdown if no Battery NTC is Present ...........................32 3.2.3.5 Overvoltage Shutdown...........................................................................32 3.3 Automatic EGPRS/GPRS Multislot Class Change ..............................................33 3.4 Charging Control..................................................................................................34 3.4.1 Battery Pack Requirements ...................................................................34 3.4.2 Batteries Recommended for Use with MC75.........................................35 3.4.3 Charger Requirements...........................................................................36 3.4.4 Implemented Charging Technique.........................................................36 3.4.5 Operating Modes during Charging.........................................................37 3.5 RTC Backup ........................................................................................................38 3.6 SIM Interface .......................................................................................................39 3.7 Serial Interface ASC0 ..........................................................................................40 3.8 Serial Interface ASC1 ..........................................................................................42 3.9 USB Interface ......................................................................................................43 3.9.1 Installing the USB Modem Driver...........................................................44 3.10 I2C Interface .........................................................................................................46 3.11 SD Memory Card Interface ..................................................................................47 3.12 Audio Interfaces...................................................................................................49 3.12.1 Speech Processing................................................................................50 3.12.2 Microphone Circuit.................................................................................50 3.12.2.1 Single-ended Microphone Input.............................................................50
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 4 of 91  15.02.2005 3.12.2.2 Differential Microphone Input.................................................................51 3.12.2.3 Line Input Configuration with OpAmp ....................................................52 3.12.3 Loudspeaker Circuit...............................................................................53 3.12.4 Digital Audio Interface DAI.....................................................................54 3.13 Control Signals ....................................................................................................56 3.13.1 Synchronization Signal ..........................................................................56 3.13.2 Using the SYNC Pin to Control a Status LED........................................57 4 Antenna Interface........................................................................................................58 4.1 Antenna Installation .............................................................................................58 4.2 Antenna Pad ........................................................................................................60 4.2.1 Suitable Cable Types.............................................................................60 4.3 Antenna Connector..............................................................................................61 5 Electrical, Reliability and Radio Characteristics......................................................65 5.1 Absolute Maximum Ratings .................................................................................65 5.2 Operating Temperatures......................................................................................65 5.3 Pin Assignment and Signal Description...............................................................66 5.4 Electrostatic Discharge ........................................................................................72 5.5 Reliability Characteristics.....................................................................................73 6 Mechanics....................................................................................................................74 6.1 Mechanical Dimensions of MC75 ........................................................................74 6.2 Mounting MC75 to the Application Platform ........................................................76 6.3 Board-to-Board Application Connector ................................................................77 7 Sample Application.....................................................................................................80 8 Reference Approval ....................................................................................................82 8.1 Reference Equipment for Type Approval.............................................................82 8.2 Compliance with FCC Rules and Regulations.....................................................83 9 Appendix......................................................................................................................84 9.1 List of Parts and Accessories ..............................................................................84 9.2 Fasteners and Fixings for Electronic Equipment .................................................86 9.2.1 Fasteners from German Supplier ETTINGER GmbH ............................86 9.3 Data Sheets of Recommended Batteries ............................................................89  Tables  Table 1: Temperature dependent behavior ............................................................................ 31 Table 2: Specifications of battery packs suitable for use with MC75 ..................................... 35 Table 3: Comparison Charge-only and Charge mode............................................................ 37 Table 4: AT commands available in Charge-only mode......................................................... 37 Table 5: Signals of the SIM interface (board-to-board connector) ......................................... 39 Table 6: DCE-DTE wiring of ASC0......................................................................................... 41 Table 7: DCE-DTE wiring of ASC1......................................................................................... 42 Table 8: SD card interface......................................................................................................47 Table 9: Overview of USC pin functions................................................................................. 54 Table 10: Return loss in the active band ................................................................................58 Table 11: Product specifications of U.FL-R-SMT connector .................................................. 61 Table 12: Material and finish of U.FL-R-SMT connector and recommended plugs ...............62 Table 13: Ordering information for Hirose U.FL Series .......................................................... 64 Table 14: Absolute maximum ratings ..................................................................................... 65 Table 15: Operating temperatures ......................................................................................... 65
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 5 of 91  15.02.2005 Table 16: Signal description...................................................................................................67 Table 17: Measured electrostatic values................................................................................72 Table 18: Summary of reliability test conditions ..................................................................... 73 Table 19: Technical specifications of Molex board-to-board connector .................................77 Table 20: List of parts and accessories..................................................................................84 Table 21: Molex sales contacts (subject to change) ..............................................................85 Table 22: Hirose sales contacts (subject to change)..............................................................85  Figures  Figure 1: MC75 system overview ...........................................................................................19 Figure 2: MC75 block diagram ............................................................................................... 20 Figure 3: Power supply limits during transmit burst................................................................ 22 Figure 4: Position of the reference points BATT+ and GND .................................................. 23 Figure 5: Power-on with operating voltage at BATT+ applied before activating IGT.............. 25 Figure 6: Power-on with IGT held low before switching on operating voltage at BATT+ .......26 Figure 7: Signal states during turn-off procedure ...................................................................29 Figure 8: Battery pack circuit diagram....................................................................................35 Figure 9: RTC supply from capacitor...................................................................................... 38 Figure 10: RTC supply from rechargeable battery .................................................................38 Figure 11: RTC supply from non-chargeable battery .............................................................38 Figure 12: Serial interface ASC0............................................................................................ 40 Figure 13: Serial interface ASC1............................................................................................ 42 Figure 14: USB circuit ............................................................................................................43 Figure 15: I2C interface connected to VCC of application ..................................................... 46 Figure 16: I2C interface connected to VEXT line of MC75..................................................... 46 Figure 17: SD card interface (example with power supply from module’s VEXT line) ........... 48 Figure 18: Audio block diagram.............................................................................................. 49 Figure 19: Single ended microphone input............................................................................. 50 Figure 20: Differential microphone input ................................................................................ 51 Figure 21: Line input configuration with OpAmp .................................................................... 52 Figure 22: Differential loudspeaker configuration...................................................................53 Figure 23: Single ended loudspeaker configuration............................................................... 53 Figure 24: PCM interface application ..................................................................................... 54 Figure 25: PCM timing............................................................................................................ 55 Figure 26: SYNC signal during transmit burst ........................................................................ 56 Figure 27: LED Circuit (Example)...........................................................................................57 Figure 28: Never use antenna connector and antenna pad at the same time ....................... 59 Figure 29: Restricted area around antenna pad..................................................................... 59 Figure 30: Mechanical dimensions of U.FL-R-SMT connector...............................................61 Figure 31: U.FL-R-SMT connector with U.FL-LP-040 plug ....................................................62 Figure 32: U.FL-R-SMT connector with U.FL-LP-066 plug ....................................................62 Figure 33: Specifications of U.FL-LP-(V)-040(01) plug .......................................................... 63 Figure 34: Pin assignment (component side of MC75) .......................................................... 66 Figure 35: MC75 – top view ................................................................................................... 74 Figure 36: Dimensions of MC75............................................................................................. 75 Figure 37: Molex board-to-board connector 52991-0808 on MC75 .......................................78 Figure 38: Mating board-to-board connector 53748-0808 on application .............................. 79 Figure 39: MC75 sample application (draft) ........................................................................... 81 Figure 40: Reference equipment for Type Approval ..............................................................82 Figure 41: Lithium Ion battery from VARTA ...........................................................................90 Figure 42: Lithium Polymer battery from VARTA ................................................................... 91
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 6 of 91  15.02.2005 0 Document History Preceding document: "MC75 Hardware Interface Description" Version 00.111 New document: "MC75 Hardware Interface Description" Version 00.190a  Chapter  What is new 2.3  Updated Figure 2 8.2  Added notes regarding FCC regulations    Preceding document: "MC75 Hardware Interface Description" Version 00.111 New document: "MC75 Hardware Interface Description" Version 00.190  Chapter  What is new 3.4.5  Described effect of AT^SMSO during Charge-only mode. 3.12.2  Corrected several parameters in figures. 3.13  More detailed description of AT^SSYNC command. 8.2  Changed antenna gain and FCC identifier.    Preceding document: "MC75 Hardware Interface Description" Version 00.02 New document: "MC75 Hardware Interface Description" Version 00.111  Chapter  What is new 3.1.2 / 3.1.3  Added description of how to measure VBATT+. 3.2.3.5  Orderly shutdown in case of overvoltage (description is preliminary) 3.4.1 / 3.4.2 9.3 Updated battery requirements. Added description of VARTA batteries. Added data sheets of VARTA batteries. 3.9.1  Added info about usbser.sys file. 3.12.2  Added filter in microphone circuit figures. 3.12.3  Added figures “Differential loudspeaker configuration” and “Single ended loudspeaker configuration”. 3.10  More detailed description of how to connect the I2C interface. 5.1  Updated Table 14: Absolute maximum ratings. 6.1  Updated Figure 36.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 7 of 91  15.02.2005 Preceding document: "MC75 Hardware Interface Description" Version 00.02 New document: "MC75 Hardware Interface Description" Version 00.65  Chapter  What is new ---  Deleted section about limitations of MC75 Preview Release. Throughout manual Supply voltage range now 3.2V – 4.3V (instead of 3.2V – 4.2V) 2.1 / 5.3  Operating temperature specified. 3.2.2.2  Added section Leakage Current in Power Down Mode. 3.4  Added Lithium Polymer batteries. Updated recommended battery specifications. More detailed description of trickle charging. 3.6  Use CCGND as separate ground line for the SIM interface. 3.9  Corrected description and figure of USB interface. Described driver installation. 3.12.4 / 5.3  USC4 pin marked as input.  5.3  Added specifications of USB interface. 5.4  Table 17: Added electrostatic values of USB and SD card interfaces. 6.1  Updated Figure 36.   Preceding document: "MC75 Hardware Interface Description" Version 00.02 New document: "MC75 Hardware Interface Description" Version 00.30  Chapter  What is new Completely revised and updated all chapters and technical specifications. Added new chapters and appendix.    Preceding document: "MC75 Hardware Interface Description" Version 00.01 New document: "MC75 Hardware Interface Description" Version 00.02  Chapter  What is new 5  Changed description of VEXT pin. Changed description of pin 55 and renamed pin from EMERGOFF to EMERG_RST.  3.11  Corrected Figure 17: SD card interface. 7  Changed sample application.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 8 of 91  15.02.2005 1 Introduction This document describes the hardware of the Siemens MC75 module that connects to the cellular device application and the air interface. It helps you quickly retrieve interface specifications, electrical and mechanical details and information on the requirements to be considered for integrating further components.   1.1 Related Documents [1]  MC75 AT Command Set [2]  MC75 Release Notes 00.190 [3]  DSB75 Support Box - Evaluation Kit for Siemens Cellular Engines [4]  Application 07: Rechargeable Lithium Batteries in GSM Applications (not yet available) [5]  Multiplexer User's Guide (not yet available)
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 9 of 91  15.02.2005 1.2  Terms and Abbreviations Abbreviation  Description ADC  Analog-to-Digital Converter AGC  Automatic Gain Control ANSI  American National Standards Institute ARFCN  Absolute Radio Frequency Channel Number ARP  Antenna Reference Point ASC0 / ASC1  Asynchronous Controller. Abbreviations used for first and second serial interface of MC75 B  Thermistor Constant B2B  Board-to-board connector BER  Bit Error Rate BTS  Base Transceiver Station CB or CBM  Cell Broadcast Message CE  Conformité Européene (European Conformity) CHAP  Challenge Handshake Authentication Protocol CPU  Central Processing Unit CS  Coding Scheme CSD  Circuit Switched Data CTS  Clear to Send DAC  Digital-to-Analog Converter DAI  Digital Audio Interface dBm0  Digital level, 3.14dBm0 corresponds to full scale, see ITU G.711, A-law DCE  Data Communication Equipment (typically modems, e.g. Siemens GSM engine) DCS 1800  Digital Cellular System, also referred to as PCN DRX  Discontinuous Reception DSB  Development Support Box DSP  Digital Signal Processor DSR  Data Set Ready DTE  Data Terminal Equipment (typically computer, terminal, printer or, for example, GSM application) DTR  Data Terminal Ready DTX  Discontinuous Transmission EDGE  Enhanced Data Rates for Global Evolution EFR  Enhanced Full Rate EGSM  Enhanced GSM EGPRS  Enhanced General Packet Radio Service EMC  Electromagnetic Compatibility
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 10 of 91  15.02.2005 Abbreviation  Description ESD  Electrostatic Discharge ETS  European Telecommunication Standard FCC  Federal Communications Commission (U.S.) FDMA  Frequency Division Multiple Access FR  Full Rate GMSK  Gaussian Minimum Shift Keying GPRS  General Packet Radio Service GSM  Global Standard for Mobile Communications HiZ  High Impedance HR  Half Rate I/O  Input/Output IC  Integrated Circuit IMEI  International Mobile Equipment Identity ISO  International Standards Organization ITU  International Telecommunications Union kbps  kbits per second LED  Light Emitting Diode Li-Ion / Li+  Lithium-Ion Li battery  Rechargeable Lithium Ion or Lithium Polymer battery Mbps  Mbits per second MMI  Man Machine Interface MO  Mobile Originated MS  Mobile Station (GSM engine), also referred to as TE MSISDN  Mobile Station International ISDN number MT  Mobile Terminated NTC  Negative Temperature Coefficient OEM  Original Equipment Manufacturer PA  Power Amplifier PAP  Password Authentication Protocol PBCCH  Packet Switched Broadcast Control Channel PCB  Printed Circuit Board PCL  Power Control Level PCM  Pulse Code Modulation PCN  Personal Communications Network, also referred to as DCS 1800 PCS  Personal Communication System, also referred to as GSM 1900 PDU  Protocol Data Unit PLL  Phase Locked Loop PPP  Point-to-point protocol
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 11 of 91  15.02.2005 Abbreviation  Description PSK  Phase Shift Keying PSU  Power Supply Unit R&TTE  Radio and Telecommunication Terminal Equipment RAM  Random Access Memory RF  Radio Frequency RMS  Root Mean Square (value) ROM  Read-only Memory RTC  Real Time Clock RTS  Request to Send Rx  Receive Direction SAR  Specific Absorption Rate SD  Secure Digital SELV  Safety Extra Low Voltage SIM  Subscriber Identification Module SMS  Short Message Service SRAM  Static Random Access Memory TA  Terminal adapter (e.g. GSM engine) TDMA  Time Division Multiple Access TE  Terminal Equipment, also referred to as DTE Tx  Transmit Direction UART  Universal asynchronous receiver-transmitter URC  Unsolicited Result Code USB  Universal Serial Bus USSD  Unstructured Supplementary Service Data VSWR  Voltage Standing Wave Ratio Phonebook abbreviations FD  SIM fixdialing phonebook LD  SIM last dialing phonebook (list of numbers most recently dialed) MC  Mobile Equipment list of unanswered MT calls (missed calls) ME  Mobile Equipment phonebook ON  Own numbers (MSISDNs) stored on SIM or ME RC  Mobile Equipment list of received calls SM  SIM phonebook
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 12 of 91  15.02.2005 1.3 Type Approval MC75 is designed to comply with the directives and standards listed below. Please note that the product is still in a pre-release state and, therefore, type approval and testing procedures have not yet been completed.  European directives 99/05/EC  “Directive of the European Parliament and of the council of 9 March 1999 on radio equipment and telecommunications terminal equipment and the mutual recognition of their conformity”, in short referred to as R&TTE Directive 1999/5/EC  89/336/EC  Directive on electromagnetic compatibility  73/23/EC  Directive on electrical equipment designed for use within certain voltage limits (Low Voltage Directive)  Standards of North American Type Approval CFR Title 47  “Code of Federal Regulations, Part 22 and Part 24 (Telecommuni-cations, PCS)”; US Equipment Authorization FCC  UL 60 950  “Product Safety Certification” (Safety requirements)      NAPRD.03  “Overview of PCS Type certification review board      Mobile Equipment Type Certification and IMEI control”     PCS Type Certification Review board (PTCRB), Version 3.1.0  RSS133 (Issue2)  Canadian Standard  Standards of European Type Approval 3GPP TS 51.010-1  “Digital  cellular  telecommunications system (Phase 2); Mobile Station (MS) conformance specification”  ETSI EN 301 511  “V7.0.1  (2000-12)  Candidate  Harmonized  European  Standard (Telecommunications series) Global System for Mobile communications (GSM); Harmonized standard for mobile stations in the GSM 900 and DCS 1800 bands covering essential requirements under article 3.2 of the R&TTE directive (1999/5/EC) (GSM 13.11 version 7.0.1 Release 1998)”   GCF-CC  “Global Certification Forum - Certification Criteria” V3.16.0   ETSI EN 301 489-1  “V1.2.1  Candidate  Harmonized  European  Standard (Telecommunications series) Electro Magnetic Compatibility and Radio spectrum Matters (ERM); Electro Magnetic Compatibility (EMC) standard for radio equipment and services; Part 1: Common Technical Requirements”  ETSI EN 301 489-7  “V1.1.1  Candidate  Harmonized  European  Standard (Telecommunications series) Electro Magnetic Compatibility and Radio spectrum Matters (ERM); Electro Magnetic Compatibility (EMC) standard for radio equipment and services; Part 7: Specific conditions for mobile and portable radio and ancillary equipment of digital cellular radio telecommunications systems (GSM and DCS)”   EN 60 950  Safety of information technology equipment (2000)
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 13 of 91  15.02.2005 Requirements of quality IEC 60068  Environmental testing  DIN EN 60529  IP codes   Compliance with international rules and regulations Manufacturers of mobile or fixed devices incorporating MC75 modules are advised to have their completed product tested and approved for compliance with all applicable national and international regulations. As a quad-band GSM/GPRS engine designed for use on any GSM network in the world, MC75 is required to pass all approvals relevant to operation on the European and North American markets. For the North American market this includes the Rules and Regulations of the Federal Communications Commission (FCC) and PTCRB, for the European market the R&TTE Directives and GCF Certification Criteria must be fully satisfied.  The FCC Equipment Authorization granted to the MC75 Siemens reference application is valid only for the equipment described in Section 8.1.   SAR requirements specific to portable mobiles Mobile phones, PDAs or other portable transmitters and receivers incorporating a GSM module must be in accordance with the guidelines for human exposure to radio frequency energy. This requires the Specific Absorption Rate (SAR) of portable MC75 based applications to be evaluated and approved for compliance with national and/or international regulations.   Since the SAR value varies significantly with the individual product design manufacturers are advised to submit their product for approval if designed for portable use. For European and US markets the relevant directives are mentioned below. It is the responsibility of the manufacturer of the final product to verify whether or not further standards, recommendations or directives are in force outside these areas.   Products intended for sale on US markets ES 59005/ANSI C95.1 Considerations for evaluation of human exposure to Electromagnetic Fields (EMFs) from Mobile Telecommunication Equipment (MTE) in the frequency range 30MHz - 6GHz   Products intended for sale on European markets EN 50360  Product standard to demonstrate the compliance of mobile phones with the basic restrictions related to human exposure to electromagnetic fields (300 MHz - 3 GHz)  Note: Usage of MC75 in a fixed, mobile or portable application is not allowed without a new FCC certification.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 14 of 91  15.02.2005 1.4 Safety Precautions The following safety precautions must be observed during all phases of the operation, usage, service or repair of any cellular terminal or mobile incorporating MC75. Manufacturers of the cellular terminal are advised to convey the following safety information to users and operating personnel and to incorporate these guidelines into all manuals supplied with the product. Failure to comply with these precautions violates safety standards of design, manufacture and intended use of the product. Siemens AG assumes no liability for customer’s failure to comply with these precautions.    When in a hospital or other health care facility, observe the restrictions on the use of mobiles. Switch the cellular terminal or mobile off, if instructed to do so by the guidelines posted in sensitive areas. Medical equipment may be sensitive to RF energy.   The operation of cardiac pacemakers, other implanted medical equipment and hearing aids can be affected by interference from cellular terminals or mobiles placed close to the device. If in doubt about potential danger, contact the physician or the manufacturer of the device to verify that the equipment is properly shielded. Pacemaker patients are advised to keep their hand-held mobile away from the pacemaker, while it is on.      Switch off the cellular terminal or mobile before boarding an aircraft. Make sure it cannot be switched on inadvertently. The operation of wireless appliances in an aircraft is forbidden to prevent interference with communications systems. Failure to observe these instructions may lead to the suspension or denial of cellular services to the offender, legal action, or both.     Do not operate the cellular terminal or mobile in the presence of flammable gases or fumes. Switch off the cellular terminal when you are near petrol stations, fuel depots, chemical plants or where blasting operations are in progress. Operation of any electrical equipment in potentially explosive atmospheres can constitute a safety hazard.    Your cellular terminal or mobile receives and transmits radio frequency energy while switched on. Remember that interference can occur if it is used close to TV sets, radios, computers or inadequately shielded equipment. Follow any special regulations and always switch off the cellular terminal or mobile wherever forbidden, or when you suspect that it may cause interference or danger.     Road safety comes first! Do not use a hand-held cellular terminal or mobile when driving a vehicle, unless it is securely mounted in a holder for speakerphone operation. Before making a call with a hand-held terminal or mobile, park the vehicle.   Speakerphones must be installed by qualified personnel. Faulty installation or operation can constitute a safety hazard.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 15 of 91  15.02.2005 SOS IMPORTANT! Cellular terminals or mobiles operate using radio signals and cellular networks. Because of this, connection cannot be guaranteed at all times under all conditions. Therefore, you should never rely solely upon any wireless device for essential communications, for example emergency calls.   Remember, in order to make or receive calls, 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 calls if certain network services or phone features are in use (e.g. lock functions, fixed dialing etc.). You may need to deactivate those features before you can make an emergency call.  Some networks require that a valid SIM card be properly inserted in the cellular terminal or mobile.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 16 of 91  15.02.2005 2 Product Concept 2.1  Key Features at a Glance Feature  Implementation General Frequency bands  Quad band: GSM 850/900/1800/1900 MHz GSM class  Small MS Output power (according to  Release 99, V5) Class 4 (+33 dBm ±2 dB) for EGSM850 Class 4 (+33 dBm ±2 dB) for EGSM900 Class 1 (+30 dBm ±2 dB) for GSM1800 Class 1 (+30 dBm ±2 dB) for GSM1900 Class E2 (+27 dBm ± 3 dB) for GSM 850 8-PSK Class E2 (+27 dBm ± 3 dB) for GSM 900 8-PSK Class E2 (+26 dBm +3 /-4 dB) for GSM 1800 8-PSK Class E2 (+26 dBm +3 /-4 dB) for GSM 1900 8-PSK  The values stated above are maximum limits. According to Release 99, Version 5, the maximum output power in a multislot configuration may be lower. The nominal reduction of maximum output power varies with the number of uplink timeslots used and amounts to 3.0 dB for 2 Tx, 4.8 dB for 3 Tx and 6.0 dB for 4 Tx.  Power supply  3.2V to 4.3V Power consumption  Sleep mode: max. TBD Power down mode: typically 50µA Operating temperature  -30°C to +65°C ambient temperature Auto switch-off at +90°C board temperature (preliminary) Physical Dimensions: 33.9mm x 44.6mm x max. 3.5mm Weight: approx. 10g GSM / GPRS/ EGPRS features Data transfer  GPRS •  Multislot Class 12 •  Full PBCCH support •  Mobile Station Class B •  Coding Scheme 1 – 4  EGPRS •  Multislot Class 10 •  Mobile Station Class B •  Modulation and Coding Scheme MCS 1 – 9
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 17 of 91  15.02.2005 Feature  Implementation CSD •  V.110, RLP, non-transparent •  2.4, 4.8, 9.6, 14.4 kbps •  USSD  PPP-stack for GPRS data transfer SMS  •  Point-to-point MT and MO •  Cell broadcast •  Text and PDU mode •  Storage: SIM card plus 25 SMS locations in mobile equipment•  Transmission of SMS alternatively over CSD or GPRS. Preferred mode can be user defined. Fax  Group 3; Class 1 Audio Speech codecs: •  Half rate HR (ETS 06.20) •  Full rate FR (ETS 06.10)  •  Enhanced full rate EFR (ETS 06.50/06.60/06.80) •  Adaptive Multi Rate AMR  Speakerphone operation Echo cancellation, noise suppression DTMF 7 ringing tones Software AT commands  AT-Hayes GSM 07.05 and 07.07, Siemens AT commands for RIL compatibility (NDIS/RIL) MicrosoftTM compatibility  RIL / NDIS for Pocket PC and Smartphone SIM Application Toolkit  SAT Release 99 TCP/IP stack  Access by AT commands IP adresses  IP version 6 Firmware update  Download over serial interface ASC0 Download over SIM interface  Download over USB Interfaces 2 serial interfaces   ASC0 •  8-wire modem interface with status and control lines, unbalanced, asynchronous •  1.2 kbps to 460 kbps •  Autobauding TBD •  Supports RTS0/CTS0 hardware handshake and software XON/XOFF flow control. •  Multiplex ability according to GSM 07.10 Multiplexer Protocol.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 18 of 91  15.02.2005 Feature  Implementation ASC1 •  4-wire, unbalanced asynchronous interface •  1.2 kbps to 460 kbps •  Autobauding TBD •  Supports RTS1/CTS1 hardware handshake and software XON/XOFF flow control USB  Supports a USB 2.0 Full Speed (12 Mbit/s) slave interface.  I2C I2C bus for transmission rates up to 400 kbps SD card interface  Interface for SD memory card or multimedia card Audio  •  2 analog interfaces •  1 digital interface (PCM) SIM interface  Supported SIM cards: 3V, 1.8V Antenna  50 Ohms. External antenna can be connected via antenna connector or solderable pad. Module interface  80-pin board-to-board connector Power on/off, Reset Power on/off  •  Switch-on by hardware pin IGT •  Switch-off by AT command (AT^SMSO) •  Automatic switch-off in case of critical temperature and voltage conditions. Reset  •  Orderly shutdown and reset by AT command •  Emergency reset by hardware pin EMERG_RST  Special features Charging  Supports management of rechargeable Lithium Ion and Lithium Polymer batteries Real time clock  Timer functions via AT commands Phonebook  SIM and phone Evaluation kit DSB75   DSB75 Evaluation Board designed to test and type approve Siemens cellular engines and provide a sample configuration for application engineering.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 19 of 91  15.02.2005 2.2  MC75 System Overview User ApplicationMC75AntennaInterfaceApplication InterfaceUSB SIM Serial 1(Modem)AnalogAudioDigitalAudio Charge PowerSupplySDinterfaceUSBHostI2CSlaveSIM cardHeadphonesor  HeadsetAudioCodecUARTSDmemorycardSerial 2ChargerChargingcircuitI2C  Figure 1: MC75 system overview
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 20 of 91  15.02.2005 2.3 Circuit Concept Figure 2 shows a block diagram of the MC75 module and illustrates the major functional components:   Baseband Block: •  Digital baseband processor with DSP •  Analog processor with power supply unit (PSU) •  Flash / SRAM (stacked) •  Application interface (board-to-board connector)  RF section: •  RF transceiver •  RF power amplifier •  RF front end •  Antenna connector    Digital Baseband Processor with DSP Analog Contro ller wit h PSUBATT+GNDIGT EM ERG_RS TASC(0)5SIM Inte rfa ceCCINCCRSTCCIOCCCLKCCVCCD(0:15)A(0:24)RD; WR; CS; WAI TRF Control BusInterfaceRF -  BasebandNTCBATT_TEMPVDDL PSYN CRF PartTrans ceiverRF PowerAmplifierSRAMFlash68MC75Application Interface (80 pins)I / Q4Au di o a na log10SD Ca rdUSB3I2C2VEX TISENSEVSE NSEVC HA RG ECHARGEGATE3RESETResetBATTYPETE M P2REFCHGASC(1)426 MHzFront EndDAI78PWR_IN DMeasuringNetwork32 .76 8kH z26 MHzRTC Figure 2: MC75 block diagram
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 21 of 91  15.02.2005 3 Application Interface MC75 is equipped with an 80-pin board-to-board connector that connects to the external application. The host interface incorporates several sub-interfaces described in the following chapters:  •  Power supply  - see Section 3.1 •  Charger interface – Section 3.4 •  SIM interface - see Section 3.6 •  Serial interface ASC0 - see Section 3.7 •  Serial interface ASC1 - see Section 3.8 •  Serial interface USB - see Section 3.9. •  Serial interface I²C - see Section 3.10 •  SD card interface - see Section 3.11 •  Two analog audio interfaces - see Section 3.12 •  Digital audio interface (DAI) - see Section 3.12 and 3.12.4 •  Status and control lines: IGT, EMERG_RST, PWR_IND, SYNC - see Table 16
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 22 of 91  15.02.2005 3.1 Power Supply MC75 needs to be connected to a power supply at the B2B connector (5 pins each BATT+ and GND).   The power supply of MC75 has to be a single voltage source at BATT+. It must be able to provide the peak current during the uplink transmission.   All the key functions for supplying power to the device are handled by the power management section of the analog controller. This IC provides the following features: •  Stabilizes the supply voltages for the GSM baseband using low drop linear voltage regulators. •  Switches the module's power voltages for the power up and down procedures. •  Delivers, across the VEXT pin, a regulated voltage for an external application. This voltage is not available in Power-down mode. •  SIM switch to provide SIM power supply.  3.1.1  Minimizing Power Losses When designing the power supply for your application please pay specific attention to power losses. Ensure that the input voltage VBATT+ never drops below 3.2 V on the MC75 board, not even in a transmit burst where current consumption can rise to typical peaks of 2A. It should be noted that MC75 switches off when exceeding these limits. Any voltage drops that may occur in a transmit burst should not exceed 400mV.  The best approach to reducing voltage drops is to use a board-to-board connection as recommended, and a low impedance power source. The resistance of the power supply lines on the host board and of a battery pack should also be considered.  Note:  If the application design requires an adapter cable between both board-to-board connectors, use a flex cable as short as possible in order to minimize power losses.   Example:  If the length of the flex cable reaches the maximum length of 100mm, this connection may cause, for example, a resistance of 30m in the BATT+ line and 30m in the GND line. As a result, a 2A transmit burst would add up to a total voltage drop of 120mV. Plus, if a battery pack is involved, further losses may occur due to the resistance across the battery lines and the internal resistance of the battery including its protection circuit.             Figure 3: Power supply limits during transmit burst Transmit burst 2ATransmit burst 2ARippleDropmin. 3.2VBATT+
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 23 of 91  15.02.2005 3.1.2  Measuring the Supply Voltage VBATT+ The reference points for measuring the supply voltage VBATT+ on the module are BATT+ and GND, both accessible at a capacitor located close to the board-to-board connector of the module.                   Figure 4: Position of the reference points BATT+ and GND    3.1.3  Monitoring Power Supply by AT Command To monitor the supply voltage you can also use the AT^SBV command which returns the value related to the reference points BATT+ and GND.   The module continuously measures the voltage at intervals depending on the operating mode of the RF interface. The duration of measuring ranges from 0.5s in TALK/DATA mode to 50s when MC75 is in IDLE mode or Limited Service (deregistered). The displayed voltage (in mV) is averaged over the last measuring period before the AT^SBV command was executed.     Reference point  BATT+ Reference point GND
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 24 of 91  15.02.2005 3.2  Power Up / Power Down Scenarios In general, be sure not to turn on MC75 while it is beyond the safety limits of voltage and temperature stated in Chapter 5. MC75 would immediately switch off after having started and detected these inappropriate conditions. In extreme cases this can cause permanent damage to the module.    3.2.1  Turn on MC75 MC75 can be started in a variety of ways as described in the following sections: •  Hardware driven start-up by IGT line: starts normal operating state (see Section 3.2.1.1) •  Software controlled reset by AT+CFUN command: starts normal operating state (see Section 3.2.1.3) •  Hardware driven start-up by VCHARGE line: starts charging algorithm and charge-only mode (see Section 3.2.1.2) •  Wake-up from Power-down mode by using RTC interrupt: starts Alarm mode   3.2.1.1  Turn on MC75 Using Ignition Line IGT When the MC75 module is in Power-down mode, it can be started to normal operation by driving the IGT (ignition) line to ground. This must be accomplished with an open drain/collector driver to avoid current flowing into this pin.   The module will start up when both of the following two conditions are met:  •  The supply voltage applied at BATT+ must be in the operating range.  •  The IGT line needs to be driven low for at least 300ms.  Considering different strategies of host application design the figures below show two approaches to meet this requirement: The example in Figure 5 assumes that IGT is activated after BATT+ has already been applied. The example in Figure 6 assumes that IGT is held low before BATT+ is switched on. In either case, to power on the module, ensure that low state of IGT takes at least 300ms from the moment the voltage at BATT+ is available.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 25 of 91  15.02.2005 If configured to a fix baud rate (AT+IPR0), the module will send the URC “^SYSSTART” to notify that it is ready to operate. If autobauding is enabled (AT+IPR=0) there will be no notification.   EMERG_RSTVEXTTXD0/TXD1/RTS0/RST1/DTR0 (driven by the application)CTS0/CTS1/DSR0/DCD0ca. 500 msSerial interfacesASC0 and ASC1Undefined ActivePWR_INDt  = 300msmin120msBATT+IGTHiZ Figure 5: Power-on with operating voltage at BATT+ applied before activating IGT
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 26 of 91  15.02.2005 EMERG_RSTPWR_INDt  = 300msmin120msBATT+IGTHiZVEXTTXD0/TXD1/RTS0/RST1/DTR0 (driven by the application)CTS0/CTS1/DSR0/DCD0ca. 500 msSerial interfacesASC0 and ASC1Undefined Active Figure 6: Power-on with IGT held low before switching on operating voltage at BATT+    3.2.1.2  Turn on MC75 Using the VCHARGE Signal As detailed in Section 3.4.5, the charging adapter can be connected regardless of the module’s operating mode. If the charger is connected to the charger input of the external charging circuit and the module’s VCHARGE pin while MC75 is off, and the battery voltage is above the undervoltage lockout threshold, processor controlled fast charging starts (see Section 3.4.4). MC75 enters a restricted mode, referred to as Charge-only mode where only the charging algorithm will be launched. During the Charge-only mode MC75 is neither logged on to the GSM network nor are the serial interfaces fully accessible. To switch to normal operation and log on to the GSM network, the IGT line needs to be activated as described in Section 3.2.1.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 27 of 91  15.02.2005 3.2.1.3  Reset MC75 via AT+CFUN Command To reset and restart the MC75 module use the command AT+CFUN. You can enter AT+CFUN=,1 or AT+CFUN=x,1, where x may be in the range from 0 to 9. See [1] for details.   If configured to a fix baud rate (AT+IPR0), the module will send the URC “^SYSSTART” to notify that it is ready to operate. If autobauding is enabled (AT+IPR=0) there will be no notification. To register to the network SIM PIN authentication is necessary after restart.   3.2.1.4  Reset MC75 in Case of Emergency via EMERG_RST Caution: Use the EMERG_RST pin only when, due to serious problems, the software is not responding for more than 5 seconds. Pulling the EMERG_RST pin causes the loss of all information stored in the volatile memory since the processor restarts immediately. Therefore, this procedure is intended only for use in case of emergency, e.g. if MC75 does not respond, if reset or shutdown via AT command fails.  The EMERG_RST signal is available on the application interface. To control the EMERG_RST line it is recommended to use an open drain / collector driver.  To actually reset the MC75 module, the EMERG_RST line must be pulled to ground for ≥10ms. After releasing the line MC75 will start again.   After hardware driven restart, notification via “^SYSSTART” URC is the same as in case of restart by IGT or AT command. To register to the network SIM PIN authentication is necessary after restart.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 28 of 91  15.02.2005 3.2.2  Turn off MC75 MC75 can be turned off as follows: •  Normal shutdown: Software controlled by AT^SMSO command •  Automatic shutdown: Takes effect if board or battery temperature is out of range or if undervoltage or overvoltage conditions occur.    3.2.2.1  Turn off MC75 Using AT Command The best and safest approach to powering down MC75 is to issue the AT^SMSO command. This procedure lets MC75 log off from the network and allows the software to enter into a secure state and safe data before disconnecting the power supply. The mode is referred to as Power-down mode. In this mode, only the RTC stays active.  Before switching off the device sends the following response:     ^SMSO: MS OFF    OK   ^SHUTDOWN  After sending AT^SMSO do not enter any other AT commands. There are two ways to verify when the module turns off:  •  Wait for the URC “^SHUTDOWN”. It indicates that data have been stored non-volatile and the module turns off in less than 1 second. •  Also, you can monitor the PWR_IND pin. High state of PWR_IND definitely indicates that the module is switched off.  Be sure not to disconnect the supply voltage VBATT+ before the URC “^SHUTDOWN” has been issued and the PWR_IND signal has gone high. Otherwise you run the risk of losing data. Signal states during turn-off are shown in Figure 7.  While MC75 is in Power-down mode the application interface is switched off and must not be fed from any other source. Therefore, your application must be designed to avoid any current flow into any digital pins of the application interface, especially of the serial interfaces. No special care is required for the USB interface which is protected from reverse current.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 29 of 91  15.02.2005 VEXT See note 1TXD0/TXD1/RTS0/RTS1/DTR0 (driven by the application)Serial interfacesASC0 and ASC1UndefinedActivePWR_INDCTS0/CTS1/DSR0/DTR0 Figure 7: Signal states during turn-off procedure  Note 1: Depending on capacitance load from host application    3.2.2.2  Leakage Current in Power Down Mode The leakage current in Power Down mode varies depending on the following conditions: •  If the supply voltage at BATT+ was disconnected and then applied again without starting up the MC75 module, the leakage current ranges between 90µA and 100µA.  •  If the MC75 module is started and afterwards powered down with AT^SMSO, then the leakage current is only 50µA.   Therefore, in order to minimize the leakage current take care to start up the module at least once before it is powered down.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 30 of 91  15.02.2005 3.2.3 Automatic Shutdown Automatic shutdown takes effect if •  the MC75 board is exceeding the critical limits of overtemperature or undertemperature •  the battery is exceeding the critical limits of overtemperature or undertemperature •  undervoltage or overvoltage is detected  The automatic shutdown procedure is equivalent to the Power-down initiated with the AT^SMSO command, i.e. MC75 logs off from the network and the software enters a secure state avoiding loss of data.   Alert messages transmitted before the device switches off are implemented as Unsolicited Result Codes (URCs). The presentation of these URCs can be enabled or disabled with the two AT commands AT^SBC and AT^SCTM. The URC presentation mode varies with the condition, please see Chapters 3.2.3.1 to 3.2.3.4 for details. For further instructions on AT commands refer to [1].    3.2.3.1  Temperature Dependent Shutdown The board temperature is constantly monitored by an internal NTC resistor located on the PCB. The NTC that detects the battery temperature must be part of the battery pack circuit as described in 3.4.1 The values detected by either NTC resistor are measured directly on the board or the battery and therefore, are not fully identical with the ambient temperature.   Each time the board or battery temperature goes out of range or back to normal, MC75 instantly displays an alert (if enabled). •  URCs indicating the level "1" or "-1" allow the user to take appropriate precautions, such as protecting the module from exposure to extreme conditions. The presentation of the URCs depends on the settings selected with the AT^SCTM write command:     AT^SCTM=1: Presentation of URCs is always enabled.      AT^SCTM=0 (default): Presentation of URCs is enabled for 15 seconds time after start-up of MC75. After 15 seconds operation, the presentation will be disabled, i.e. no alert messages can be generated.  •  URCs indicating the level "2" or "-2" are instantly followed by an orderly shutdown. The presentation of these URCs is always enabled, i.e. they will be output even though the factory setting AT^SCTM=0 was never changed.  The maximum temperature ratings are stated in Table 15. Refer to Table 1 for the associated URCs. All statements are based on test conditions according to IEC 60068-2-2 (still air).
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 31 of 91  15.02.2005 Table 1: Temperature dependent behavior Sending temperature alert (15 s after MC75 start-up, otherwise only if URC presentation enabled) ^SCTM_A:  1  Caution: Tamb of battery close to overtemperature limit. ^SCTM_B:  1  Caution: Tamb of board close to overtemperature limit. ^SCTM_A:  -1  Caution: Tamb of battery close to undertemperature limit. ^SCTM_B:  -1  Caution: Tamb of board close to undertemperature limit. ^SCTM_A: 0  Battery back to uncritical temperature range. ^SCTM_B: 0  Board back to uncritical temperature range. Automatic shutdown (URC appears no matter whether or not presentation was enabled) ^SCTM_A:  2  Alert:  Tamb of battery equal or beyond overtemperature limit. MC75 switches off. ^SCTM_B:  2  Alert: Tamb of board equal or beyond overtemperature limit. MC75 switches off. ^SCTM_A:  -2  Alert: Tamb of battery equal or below undertemperature limit. MC75 switches off.^SCTM_B:  -2  Alert: Tamb of board equal or below undertemperature limit. MC75 switches off.    3.2.3.2  Temperature Control during Emergency call If the temperature limit is exceeded while an emergency call is in progress the engine continues to measure the temperature, but deactivates the shutdown functionality. If the temperature is still out of range when the call ends, the module switches off immediately (without another alert message).    3.2.3.3  Undervoltage Shutdown if Battery NTC is Present In applications where the module’s charging technique is used and an NTC is connected to the BATT_TEMP terminal, the software constantly monitors the applied voltage. If the measured battery voltage is no more sufficient to set up a call the following URC will be presented:    ^SBC:  Undervoltage.  The message will be reported, for example, when you attempt to make a call while the voltage is close to the critical limit and further power loss is caused during the transmit burst. To remind you that the battery needs to be charged soon, the URC appears several times before the module switches off.   To enable or disable the URC use the AT^SBC command. The URC will be enabled when you enter the write command and specify the current consumption of your host application. Step by step instructions are provided in [1].
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 32 of 91  15.02.2005 3.2.3.4  Undervoltage Shutdown if no Battery NTC is Present The undervoltage protection is also effective in applications, where no NTC connects to the BATT_TEMP terminal. Thus, you can take advantage of this feature even though the application handles the charging process or MC75 is fed by a fixed supply voltage. All you need to do is executing the write command AT^SBC=<current> which automatically enables the presentation of URCs. You do not need to specify <current>.   Whenever the supply voltage falls below the specified value (see table TBD.) the URC    ^SBC:  Undervoltage appears several times before the module switches off.   3.2.3.5 Overvoltage Shutdown In the event of the voltage rising above the maximum voltage (see Table TBD) the module sends a URC and then performs an orderly shutdown. Further details: TBD  Keep in mind that several MC75 components are directly linked to BATT+ and, therefore, the supply voltage remains applied at major parts of MC75, even if the module is switched off. Especially the power amplifier is very sensitive to high voltage and might even be destroyed.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 33 of 91  15.02.2005 3.3  Automatic EGPRS/GPRS Multislot Class Change Temperature control is also effective for operation in EGPRS Multislot Class 10 and GPRS Multislot Class 12. If the board temperature increases to the limit specified for restricted operation1) while data are transmitted over EGPRS or GPRS, the module automatically reverts  •  from EGPRS Multislot Class 10 (2 Tx slots) to EGPRS Multislot Class 8 (1Tx), •  from GPRS Multislot Class 12 (4 Tx slots) to GPRS Multislot Class 8 (1Tx), •  from GPRS Multislot Class 10 (2 Tx slots) to GPRS Multislot Class 8 (1Tx)  This reduces the power consumption and, consequently, causes the board’s temperature to decrease. Once the temperature drops to a value of 5 degrees below the limit of restricted operation, MC75 returns to the higher Multislot Class. If the temperature stays at the critical level or even continues to rise, MC75 will not switch back to the higher class.   After a transition from EGPRS Multislot Class 10 to EGPRS Multislot Class 8 a possible switchback to EGPRS Multislot Class 10 is blocked for one minute. The same applies when a transition occurs from GPRS Multislot Class 12 or 10 to GPRS Multislot Class 8.   Please note that there is not one single cause of switching over to a lower Multislot Class. Rather it is the result of an interaction of several factors, such as the board temperature that depends largely on the ambient temperature, the operating mode and the transmit power. Furthermore, take into account that there is a delay until the network proceeds to a lower or, accordingly, higher Multislot Class. The delay time is network dependent. In extreme cases, if it takes too much time for the network and the temperature cannot drop due to this delay, the module may even switch off as described in Section 3.2.3.1.   1) See Table 15 for temperature limits known as restricted operation.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 34 of 91  15.02.2005 3.4 Charging Control MC75 integrates a charging management for rechargeable Lithium Ion and Lithium Polymer batteries. You can skip this chapter if charging is not your concern, or if you are not using the implemented charging algorithm.  MC75 has no on-board charging circuit. To benefit from the implemented charging management you are required to install a charging circuit within your application according to the Figure 39.   The following sections contain an overview of charging and battery specifications. Please refer to [4] for greater detail, especially regarding requirements for batteries and chargers, appropriate charging circuits, recommended batteries and an analysis of operational issues typical of battery powered GSM/GPRS applications.  3.4.1  Battery Pack Requirements The charging algorithm has been optimized for rechargeable Lithium batteries that meet the characteristics listed below and in Table 2. It is recommended that the battery pack you want to integrate into your MC75 application is compliant with these specifications. This ensures reliable operation, proper charging and, particularly, allows you to monitor the battery capacity using the AT^SBC command (see [1] for details). Failure to comply with these specifications might cause AT^SBC to deliver incorrect battery capacity values.   •  Li-Ion or Lithium Polymer battery pack specified for a maximum charging voltage of 4.2 V and a recommended capacity of 1000 to 1200 mAh.  •  Since charging and discharging largely depend on the battery temperature, the battery pack should include an NTC resistor. If the NTC is not inside the battery it must be in thermal contact with the battery. The NTC resistor must be connected between BATT_TEMP and GND.  The B value of the NTC should be in the range: 10 kΩ +5% @ 25°C, B25/85 = 3423K to B =3435K ± 3% (alternatively acceptable: 10 kΩ +2% @ 25°C, B25/50 = 3370K +3%). Please note that the NTC is indispensable for proper charging, i.e. the charging process will not start if no NTC is present. •  Ensure that the pack incorporates a protection circuit capable of detecting overvoltage (protection against overcharging), undervoltage (protection against deep discharging) and overcurrent. Due to the discharge current profile typical of GSM applications, the circuit must be insensitive to pulsed current. •  On the MC75 module, a built-in measuring circuit constantly monitors the supply voltage. In the event of undervoltage, it causes MC75 to power down. Undervoltage thresholds are specific to the battery pack and must be evaluated for the intended model. When you evaluate undervoltage thresholds, consider both the current consumption of MC75 and of the application circuit.  •  The internal resistance of the battery and the protection should be as low as possible. It is recommended not to exceed 150m, even in extreme conditions at low temperature. The battery cell must be insensitive to rupture, fire and gassing under extreme conditions of temperature and charging (voltage, current). •  The battery pack must be protected from reverse pole connection. For example, the casing should be designed to prevent the user from mounting the battery in reverse orientation. •  It is recommended that the battery pack be approved to satisfy the requirements of CE conformity.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 35 of 91  15.02.2005 Figure 8 shows the circuit diagram of a typical battery pack design that includes the protection elements described above.          Figure 8: Battery pack circuit diagram  Table 2: Specifications of battery packs suitable for use with MC75 Battery type  Rechargeable Lithium Ion or Lithium Polymer battery Nominal voltage  3.6V / 3.7V Capacity  Recommended: 1000mAh to 1200mAh Minimum: 500mAh NTC  10k ± 5% @ 25°C B value range: B (25/85)=3423K to B =3435K ± 3% Overcharge detection voltage  4.325 ± 0.025V Overdischarge detection voltage  2.5 ± 0.05V Overcurrent detection  3 ± 0.5A Overcurrent detection delay time  4ms Short detection delay time  50µs Internal resistance  <130m Note: A maximum internal resistance of 150m should not be exceeded even after 500 cycles and under extreme conditions.  3.4.2  Batteries Recommended for Use with MC75 When you choose a battery for your MC75 application you can take advantage of one of the following two batteries offered by VARTA Microbattery GmbH. Both batteries meet all requirements listed above. They have been thoroughly tested by Siemens and proved to be equally suited for MC75.  •  LIP 633450A1B PCM.STB, type Lithium Ion This battery is listed in the standard product range of VARTA. Incorporated in a shrink sleeve, the battery is CE approved. Therefore it has been chosen for integration into the reference setup submitted for Type Approval of Siemens GSM modules.  •  LPP 503759CA PCM.NTC.LT50, type Lithium Polymer This battery has been especially designed by VARTA for use with Siemens GSM modules. It has the same properties as the above Li-Ion battery, except that it is type Polymer, is smaller, comes without casing and is not CE approved.  Specifications, construction drawings and sales contacts for both VARTA batteries can be found in Section 9.3.  to BATT_TEMP to GNDNTCPolyfuseϑProtection Circuit+-Battery cellto BATT+
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 36 of 91  15.02.2005 3.4.3 Charger Requirements For using the implemented charging algorithm and the reference charging circuit recommended in [4] and in Figure 39, the charger has to meet the following requirements: Output voltage:   5.2Volts ±0.2V (stabilized voltage) Output current:   500mA     Chargers with a higher output current are acceptable, but please consider that only 500mA will be applied when a 0.3 Ohms shunt resistor is connected between VSENSE and ISENSE. See [4] for further details.   3.4.4  Implemented Charging Technique If the external charging circuit of your application and the charger meet the requirements listed above, charging is enabled in various stages depending on the battery condition:   Trickle charging: •  Trickle charge current flows over the VCHARGE line. •  Trickle charging is done when a charger is present (connected to VCHARGE) and the battery is deeply discharged or has undervoltage. If deeply discharged (Deep Discharge Lockout at VBATT+= 0…2.5V) the battery is charged with 5mA, in case of undervoltage (Undervoltage Lockout at VBATT+= 2.5…3.2V) it is charged with 25mA  Software controlled charging: •  Controlled over the CHARGEGATE. •  Temperature conditions: 0°C to 45°C •  Software controlled charging is done when the charger is present (connected to VCHARGE) and the battery voltage is at least above the undervoltage threshold. Software controlled charging passes the following stages: -  Power ramp: Depending on the discharge level of the battery (i.e. the measured battery voltage VBATT+) the software adjusts the maximum charge current for charging the battery. The duration of power ramp charging is very short (less than 30 seconds). -  Fast charging: Battery is charged with constant current (approx. 500mA) until the battery voltage reaches 4.2V (approx. 70% of the battery capacity).  -  Top-up charging: The battery is charged with constant voltage of 4.2V at stepwise reducing charge current until full battery capacity is reached.  •  The duration of software controlled charging depends on the battery capacity and the level of discharge.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 37 of 91  15.02.2005 3.4.5  Operating Modes during Charging Of course, the battery can be charged regardless of the engine's operating mode. When the GSM module is in Normal mode (SLEEP, IDLE, TALK, GPRS IDLE or GPRS DATA mode), it remains operational while charging is in progress (provided that sufficient voltage is applied). The charging process during the Normal mode is referred to as Charge mode.   If the charger is connected to the charger input of the external charging circuit and the module’s VCHARGE pin while MC75 is in Power-down mode, MC75 goes into Charge-only mode.   Table 3: Comparison Charge-only and Charge mode  How to activate mode  Description of mode Charge mode Connect charger to charger input of host application charging circuit and module’s VCHARGE pin while MC75 is •  operating, e.g. in IDLE or TALK mode •  in SLEEP mode •  Battery can be charged while GSM module remains operational and registered to the GSM network. •  In IDLE and TALK mode, the serial interfaces are accessible. All AT commands can be used to full extent. NOTE: If the module operates at maximum power level (PCL5) and GPRS Class 12 at the same time current consumption is higher than the current supplied by the charger. Charge-only mode Connect charger to charger input of host application charging circuit and module’s VCHARGE pin while MC75 is •  in Power-down mode •  in Normal mode: Connect charger to the VCHARGE pin, then enter AT^SMSO.  NOTE: While trickle charging is in progress, be sure that the host application is switched off. If the application is fed from the trickle charge current the module might be prevented from proceeding to software controlled charging since the current would not be sufficient.  •  Battery can be charged while GSM engine is deregistered from GSM network. •  Charging runs smoothly due to constant current consumption. •  The AT interface is accessible and allows to use the commands listed below.    Table 4: AT commands available in Charge-only mode AT command  Use AT+CALA  Set alarm time AT+CCLK  Set date and time of RTC AT^SBC  Query status of charger connection. Enable / disable “^SBC” URCs. AT^SCTM  Query temperature range, enable/disable URCs to report critical temperature ranges AT^SMSO  AT^SMSO shuts down the module, but if the charger remains connected the module will automatically restart into Charge-only mode.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 38 of 91  15.02.2005 3.5 RTC Backup The internal Real Time Clock of MC75 is supplied from a separate voltage regulator in the analog controller which is also active when MC75 is in POWER DOWN status. An alarm function is provided that allows to wake up MC75 without logging on to the GSM network.   In addition, you can use the VDDLP pin on the board-to-board connector to backup the RTC from an external capacitor or a battery (rechargeable or non-chargeable). The capacitor is charged by the BATT+ line of MC75. If the voltage supply at BATT+ is disconnected the RTC can be powered by the capacitor. The size of the capacitor determines the duration of buffering when no voltage is applied to MC75, i.e. the larger the capacitor the longer MC75 will save the date and time.   A serial 1k resistor placed on the board next to VDDLP limits the charge current of an empty capacitor or battery.   The following figures show various sample configurations. Please refer to Table 16 for the parameters required.    Baseband processor RTC PSU+BATT+ 1kB2BVDDLP Figure 9: RTC supply from capacitor   RTC +BATT+ 1kB2BVDDLPBaseband processor PSU Figure 10: RTC supply from rechargeable battery   RTC ++BATT+ 1kVDDLPB2BBaseband processor PSU Figure 11: RTC supply from non-chargeable battery
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 39 of 91  15.02.2005 3.6 SIM Interface The baseband processor has an integrated SIM interface compatible with the ISO 7816 IC Card standard. This is wired to the host interface (board-to-board connector) in order to be connected to an external SIM card holder. Six pins on the board-to-board connector are reserved for the SIM interface.   The SIM interface supports 3V and 1.8V SIM cards. Please refer to Table 16 for electrical specifications of the SIM interface lines depending on whether a 3V or 1.8V SIM card is used.  The CCIN pin serves to detect whether a tray (with SIM card) is present in the card holder. Using the CCIN pin is mandatory for compliance with the GSM 11.11 recommendation if the mechanical design of the host application allows the user to remove the SIM card during operation. To take advantage of this feature, an appropriate SIM card detect switch is required on the card holder. For example, this is true for the model supplied by Molex, which has been tested to operate with MC75 and is part of the Siemens reference equipment submitted for type approval. See Chapter 8 for Molex ordering numbers.  Table 5: Signals of the SIM interface (board-to-board connector) Signal  Description CCGND  Separate ground connection for SIM card to improve EMC.  Be sure to use this ground line for the SIM interface rather than any other ground pin or plane on the module. A design example for grounding the SIM interface is shown in Figure 39. CCCLK  Chipcard clock, various clock rates can be set in the baseband processor. CCVCC  SIM supply voltage. CCIO  Serial data line, input and output. CCRST  Chipcard reset, provided by baseband processor. CCIN  Input on the baseband processor for detecting a SIM card tray in the holder. If the SIM is removed during operation the SIM interface is shut down immediately to prevent destruction of the SIM. The CCIN pin is mandatory for applications that allow the user to remove the SIM card during operation.  The CCIN pin is solely intended for use with a SIM card. It must not be used for any other purposes. Failure to comply with this requirement may invalidate the type approval of MC75.  The total cable length between the board-to-board connector pins on MC75 and the pins of the external SIM card holder must not exceed 100 mm in order to meet the specifications of 3GPP TS 51.010-1 and to satisfy the requirements of EMC compliance.  To avoid possible cross-talk from the CCCLK signal to the CCIO signal be careful that both lines are not placed closely next to each other. A useful approach is using the CCGND line to shield the CCIO line from the CCCLK line.  Note: No guarantee can be given, nor any liability accepted, if loss of data is encountered after removing the SIM card during operation.    Also, no guarantee can be given for properly initializing any SIM card that the user inserts after having removed a SIM card during operation. In this case, the application must restart MC75.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 40 of 91  15.02.2005 3.7  Serial Interface ASC0 MC75 offers an 8-wire unbalanced, asynchronous modem interface ASC0 conforming to ITU-T V.24 protocol DCE signalling. The electrical characteristics do not comply with ITU-T V.28. The significant levels are 0V (for low data bit or active state) and 2.9V (for high data bit or inactive state). For electrical characteristics please refer to Table 16.  MC75 is designed for use as a DCE. Based on the conventions for DCE-DTE connections it communicates with the customer application (DTE) using the following signals: •  Port TXD @ application sends data to the module’s TXD0 signal line •  Port RXD @ application receives data from the module’s RXD0 signal line  GSM module (DCE) Application (DTE)TXDRXDRTSCTSRINGDCDDSRDTRTXD0RXD0RTS0CTS0RING0DCD0DSR0DTR0 Figure 12: Serial interface ASC0  Features •  Includes the data lines TXD0 and RXD0, the status lines RTS0 and CTS0 and, in addition, the modem control lines DTR0, DSR0, DCD0 and RING0.  •  ASC0 is primarily designed for controlling voice calls, transferring CSD, fax and GPRS data and for controlling the GSM engine with AT commands.  •  Full Multiplex capability allows the interface to be partitioned into three virtual channels, yet with CSD and fax services only available on the first logical channel. Please note that when the ASC0 interface runs in Multiplex mode, ASC1 cannot be used. For more details on Multiplex mode see [5]. •  The DTR0 signal will only be polled once per second from the internal firmware of MC75.  •  The RING0 signal serves to indicate incoming calls and other types of URCs (Unsolicited Result Code). It can also be used to send pulses to the host application, for example to wake up the application from power saving state. See [1] for details on how to configure the RING0 line by AT^SCFG. •  By default, configured for 8 data bits, no parity and 1 stop bit. The setting can be changed using the AT command AT+ICF and, if required, AT^STPB. For details see [1]. •  ASC0 can be operated at bit rates from 300bps to 460800 bps. •  Autobauding supports the following bit rates: TBD.  •  Autobauding is not compatible with multiplex mode. •  Supports RTS0/CTS0 hardware flow control and XON/XOFF software flow control.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 41 of 91  15.02.2005 Table 6: DCE-DTE wiring of ASC0 DCE  DTE V.24 circuit  Pin function  Signal direction  Pin function  Signal direction 103  TXD0 Input  TXD  Output 104  RXD0 Output  RXD  Input 105  RTS0 Input  RTS  Output 106  CTS0 Output  CTS  Input 108/2  DTR0 Input  DTR  Output 107  DSR0 Output  DSR  Input 109  DCD0 Output  DCD  Input 125  RING0 Output  /RING  Input
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 42 of 91  15.02.2005 3.8  Serial Interface ASC1 MC75 offers a 4-wire unbalanced, asynchronous modem interface ASC1 conforming to ITU-T V.24 protocol DCE signalling. The electrical characteristics do not comply with ITU-T V.28. The significant levels are 0V (for low data bit or active state) and 2.9V (for high data bit or inactive state). For electrical characteristics please refer to Table 16.  MC75 is designed for use as a DCE. Based on the conventions for DCE-DTE connections it communicates with the customer application (DTE) using the following signals: •  Port TXD @ application sends data to module’s TXD1 signal line •  Port RXD @ application receives data from the module’s RXD1 signal line  GSM module (DCE) Application (DTE)TXDRXDRTSCTSTXD1RXD1RTS1CTS1 Figure 13: Serial interface ASC1  Features •  Includes only the data lines TXD1 and RXD1 plus RTS1 and CTS1 for hardware handshake.  •  On ASC1 no RING line is available. The indication of URCs on the second interface depends on the settings made with the AT^SCFG command. For details refer to [1]. •  Configured for 8 data bits, no parity and 1 or 2 stop bits. •  ASC1 can be operated at bit rates from 300bps to 460800 bps.  •  Autobauding TBD. •  Supports RTS1/CTS1 hardware flow control and XON/XOFF software flow control.  Table 7: DCE-DTE wiring of ASC1 DCE  DTE V.24 circuit  Pin function  Signal direction  Pin function  Signal direction 103  TXD1 Input  TXD  Output 104  RXD1 Output  RXD  Input 105  RTS1 Input  RTS  Output 106  CTS1 Output  CTS  Input
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 43 of 91  15.02.2005 3.9 USB Interface MC75 supports a USB 2.0 Full Speed (12 Mbit/s) device interface. It is primarily intended for use as command and data interface and for downloading firmware.  The USB I/O-pins are capable of driving the signal at min 3.0V. They are 5V I/O compliant.  To properly connect the module’s USB interface to the host a USB 2.0 compatible connector is required. Furthermore, the USB modem driver delivered with MC75 must be installed as described below.  The USB host is responsible for supplying, across the VUSB_IN line, power to the module’s USB interface, but not to other MC75 interfaces. This is because MC75 is designed as a self-powered device compliant with the “Universal Serial Bus Specification Revision 2.0”1.   MCUUSBTransceiverlin.RegulatorPSUBaseband controllerGSM  moduleHost22Ohms22Ohms1.5kOhmsUSB_DPUSB_DNVUSB_IN5V3VD+D-VBUSGND80 pole board-to-board connector Figure 14: USB circuit                                                    1  The specification is ready for download on http://www.usb.org/developers/docs/
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 44 of 91  15.02.2005 3.9.1  Installing the USB Modem Driver This section assumes you are familiar with installing and configuring a modem under Windows 2000 and Windows XP. As both operating systems use multiple methods to access modem settings this section provides only a brief summary of the most important steps.   Take care that the “usbmodem.inf” file delivered with MC75 is at hand. Connect the USB cable to the MC75 host application (for example the evaluation board DSB75) and the PC. Windows detects MC75 as a new USB modem, opens the Found New Hardware Wizard and reports that it is searching for the “Siemens AG WM USB Modem” driver. Follow the instructions on the screen and specify the path where the “usbmodem.inf” file is located. Windows will copy the required software to your computer and configure the modem by assigning a free COM port. If you are already using more than one COM port then the next free one will be allocated. Click Finish to complete the installation.  Notes for Windows 2000 only:  •  During the installation procedure you will be prompted for the “usbser.sys” driver. Make sure the file is present before you start installing the above inf file.  The “usbser.sys” file is not delivered as a single file, but must be extracted from a Windows 2000 cabinet file. This is either the file “driver.cab” located in the “I386” folder of the original Windows 2000 CD or a later cabinet file inside the Service Pack. SP4 for example includes the “sp4.cab” file which can be found in its “I386” folder. The “usbser.sys” driver from the Service Pack has priority over one provided with the standard Windows 2000 install CD.  •  It is necessary to restart Windows 2000 to make the changes take effect.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 45 of 91  15.02.2005  You can find the “Siemens AG WM USB Modem” listed under Control Panel | Phone and Modem Options | Modems.                      Troubleshooting for installation problems  If Windows fails to assign the next free COM port to MC75 and, for example, allocates a COM port already used by another modem you can manually select a free port as follows:  Open the Windows Device Manager, select the installed “Siemens AG WM USB Modem”, click  Properties, select the  Advanced tab and click  Advanced Port settings. From the listbox  COM Port Number choose a free port. To make the changes take effect disconnect and re-connect the USB cable. If not yet successful, also restart Windows.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 46 of 91  15.02.2005 3.10 I2C Interface I2C is a serial, 8-bit oriented data transfer bus for bit rates up to 400 kbps in Fast mode. It consists of two lines, the serial data line I2CDAT and the serial clock line I2CCLK.   The MC75 module acts as a single master device, e.g. the clock I2CCLK is driven by module. I2CDAT is a bi-directional line.  Each device connected to the bus is software addressable by a unique address, and simple master/slave relationships exist at all times. The module operates as master-transmitter or as master-receiver. The customer application transmits or receives data only on request of the module. To configure and activate the I2C interface use the AT^SSPI command described in [1].  The I2C interface can be powered from an external supply or via the VEXT line of MC75. If connected to the VEXT line the I2C interface will be properly shut down when the module enters the Power-down mode. If you prefer to connect the I2C interface to an external power supply, take care that VCC of the application is in the range of VVEXT and that the interface is shut down when the PWR_IND signal goes high. See figures below as well as Section 7 and Figure 39.  In the application I2CDAT and I2CCLK lines need to be connected to a positive supply voltage via a pull-up resistor.   For electrical characteristics please refer to Table 16.  GSM moduleI2DATI2CCLKGNDI2DATI2CCLKGNDApplicationVCCRpRpwVEXT Figure 15: I2C interface connected to VCC of application  GSM moduleI2DATI2CCLKGNDI2DATI2CCLKGNDApplicationVEXTRpRp Figure 16: I2C interface connected to VEXT line of MC75  Note: Good care should be taken when creating the PCB layout of the host application: The traces of I2CCLK and I2CDAT should be equal in length and as short as possible.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 47 of 91  15.02.2005 3.11  SD Memory Card Interface The SD card interface is compliant with the “SD Memory Card Specifications / Part 1 Physical Layer Specification, Version 1.01”.   The interface supports the following features: •  Data rates up to 3250 kByte/s.  •  The read/write data rate depends on the clock rate. •  SD card insertion detection (at SD_D3-line) or via SD_DET line as option (CD switch in SD card holder required) •  Write protect detection via SD_WP line is optional (WP switch in SD card holder required) •  Maximum capacity of SD cards compliant with the above SD Memory Card Specification is 4 GByte.  The SD memory card interface can be powered from an external supply or via the VEXT line of MC75. If connected to the VEXT line the SD memory card interface will be properly shut down when the module enters the Power-down mode. If you prefer to connect the SD card interface to an external power supply, take care that the interface is shut down when the PWR_IND signal goes high. See also Section 7 and Figure 39.  Note: No guarantee can be given, nor any liability accepted, if loss of data is encountered after removing the SD memory card during operation.  Table 8: SD card interface Signal  I/O  Description  Remark SD_D0 I/O  --- SD_D1 I/O  --- SD_D2 I/O  --- SD_D3 I/O 4 bit data bus Card detect at power on: 0 or open  = Card removed 1 or 50k pullup  = Card inserted Note: This is no removal detection during card operation!  SD_CMD  O  Command / Response   SD_CLK  O  Clock   25.4kHz …13MHz Clock rise and fall time: max. 10ns  SD_WP  I  Write protect detection  0= unlocked 1= locked (External pull-up resistor required) SD_DET I  Card detection (optional) 0= card inserted 1= card removed  Power supply from external source or from VEXT line Required power supply: min. 2.7V, max. 3.6V.   Note: Good care should be taken when creating the PCB layout of the host application: The traces of SD_CLK, SD_CMD, and SD_D(0..3) should be equal in length and as short as possible.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 48 of 91  15.02.2005 SD_CLKSD_CMDSD_WPSD_D0SD_D1SD_D2SD_D3VEXT876543219DAT1DAT0GNDCLKVDDGNDCMDCD/DAT3DAT2lockunlockWriteprotectslideCarddetectSD card holderSD card50k1)1) Internal switch is closed after power-up and open during regular data transfer. Used for card detection.SD_DET47kGSM module80 pole board-to-board connectorBasebandcontrollerAnalog controller Figure 17: SD card interface (example with power supply from module’s VEXT line)
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 49 of 91  15.02.2005 3.12 Audio Interfaces MC75 comprises three audio interfaces available on the board-to-board connector:  •  Two analog audio interfaces, both with balanced or single-ended inputs/outputs. •  Serial digital audio interface (DAI) designed for PCM (Pulse Code Modulation).  This means you can connect up to three different audio devices, although only one interface can be operated at a time. Using the AT^SAIC command you can easily switch back and forth.   Analog switch Digital Audio Interface AirInterfaceDSP MUX MUXD AMICN2 MICP2 MICN1 MICP1 USC6 USC5 USC4 USC3 USC2 AGND USC0 USC1 DA EPP2 EPN2 EPP1 EPN1 VMIC MUX  Figure 18: Audio block diagram To suit different types of accessories the audio interfaces can be configured for different audio modes via the AT^SNFS command. The electrical characteristics of the voiceband part vary with the audio mode. For example, sending and receiving amplification, sidetone paths, noise suppression etc. depend on the selected mode and can be altered with AT commands (except for mode 1).  Both analog audio interfaces can be used to connect headsets with microphones or speakerphones. Headsets can be operated in audio mode 3, speakerphones in audio mode 2. Audio mode 5 can be used for a speech coder without signal pre or post processing.   When shipped from factory, all audio parameters of MC75 are set to interface 1 and audio mode 1. This is the default configuration optimized for the Votronic HH-SI-30.3/V1.1/0 handset and used for type approving the Siemens reference configuration. Audio mode 1 has fix parameters which cannot be modified. To adjust the settings of the Votronic handset simply change to another audio mode.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 50 of 91  15.02.2005 3.12.1 Speech Processing The speech samples from the ADC or DAI are handled by the DSP of the baseband controller to calculate e.g. amplifications, sidetone, echo cancellation or noise suppression depending on the configuration of the active audio mode. These processed samples are passed to the speech encoder. Received samples from the speech decoder are passed to the DAC or DAI after post processing (frequency response correction, adding sidetone etc.).  Full rate, half rate, enhanced full rate, adaptive multi rate (AMR), speech and channel encoding including voice activity detection (VAD) and discontinuous transmission (DTX) and digital GMSK modulation are also performed on the GSM baseband processor.  3.12.2 Microphone Circuit MC75 has two identical analog microphone inputs. There is no on-board microphone supply circuit, except for the internal voltage supply VMIC and the dedicated audio ground line AGND. Both lines are well suited to feed a balanced audio application or a single-ended audio application.   The AGND line on the MC75 board is especially provided to achieve best grounding conditions for your audio application. As there is less current flowing than through other GND lines of the module or the application, this solution will avoid hum and buzz problems.   3.12.2.1 Single-ended Microphone Input Figure 19 as well as Figure 39 show an example of how to integrate a single-ended microphone input.   GSM moduleRBVBiasCKAGNDMICNxMICPxVMICRARACFRVMICRA = typ. 2k RB = typ. 5k RVMIC = typ. 470Ohm  Ck = typ. 100nF CF = typ. 22µF  VMIC = typ. 2.5V  Vbias = 1.0V … 1.6V, typ. 1.5V Figure 19: Single ended microphone input    RA has to be chosen so that the DC voltage across the microphone falls into the bias voltage range of 1.0V to 1.6V and the microphone feeding current meets its specification.  The MICNx input is automatically self biased to the MICPx DC level. It is AC coupled via CK to a resistive divider which is used to optimize supply noise cancellation by the differential microphone amplifier in the module.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 51 of 91  15.02.2005 The VMIC voltage should be filtered if gains larger than 20dB are used. The filter can be attached as a simple first order RC-network (RVMIC and CF).  This circuit is well suited if the distance between microphone and module is kept short. Due to good grounding the microphone can be easily ESD protected as its housing usually connects to the negative terminal.     3.12.2.2  Differential Microphone Input Figure 20 shows a differential solution for connecting an electret microphone.   GSM moduleRARAVBiasCKAGNDMICNxMICPxVMICCFRVMIC RA = typ. 1k RVMIC = 470Ohm  CK = typ. 100nF CF = typ. 22µF  VMIC = typ. 2.5V  Vbias = 1.0V … 1.6V, typ. 1.5V Figure 20: Differential microphone input     The resulting DC voltage between MICPx and AGND should be in the range of 1.0V to 1.6V to bias the input amplifier. MICNx is automatically self biased to the MICPx DC level. The resulting AC differential voltage is then amplified in the GSM module.   The VMIC voltage should be filtered if gains larger than 20dB are used. The filter can be attached as a simple first order RC-network (RVMIC and CF).  The advantage of this circuit is that it can be used if the application involves longer lines between microphone and module.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 52 of 91  15.02.2005 3.12.2.3  Line Input Configuration with OpAmp Figure 21 shows an example of how to connect an opamp into the microphone circuit.  GSM moduleRVBiasCKAGNDMICNxMICPxVMICRCK~RVMICCF RA = typ. 47k RVMIC = 470Ohm  Ck = typ. 100nF CF = typ. 22µF  VMIC = typ. 2.5V  Vbias = typ. ½ VMIC = 1.25V Figure 21: Line input configuration with OpAmp     The AC source (e.g. an opamp) and its reference potential have to be AC coupled to the MICPx resp. MICNx input terminals. The voltage divider between VMIC and AGND is necessary to bias the input amplifier. MICNx is automatically self biased to the MICPx DC level.   The VMIC voltage should be filtered if gains larger than 20dB are used. The filter can be attached as a simple first order RC-network (RVMIC and CF). If a high input level and a lower gain are applied the filter is not necessary.  If desired, MICNx via CK can also be connected to the inverse output of the AC source instead of connecting it to the reference potential for differential line input.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 53 of 91  15.02.2005 3.12.3 Loudspeaker Circuit The GSM module comprises two analog speaker outputs: EP1 and EP2. Output EP1 is able to drive a load of 8Ohms while the output EP2 can drive a load of 32Ohms. Each interface can be connected in differential and in single ended configuration. See examples in Figure 22 and Figure 23.  GSM moduleAGNDEPNxEPPx  Figure 22: Differential loudspeaker configuration Loudspeaker impedance  EPP1/EPN1 ZL = typ. 8Ohm  EPP2/EPN2 ZL = typ. 32Ohm  GSM moduleAGNDEPNxEPPx+Ck  Figure 23: Single ended loudspeaker configuration Loudspeaker impedance  EPP1/EPN1 ZL = typ. 8Ohm Ck = 220µF  EPP2/EPN2 ZL = typ. 32Ohm Ck = 47µF
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 54 of 91  15.02.2005 3.12.4  Digital Audio Interface DAI The DAI can be used to connect audio devices capable of PCM (Pulse Code Modulation), for example a codec. Table 9: Overview of USC pin functions Signal name on  B2B connector Function for PCM Interface  Input/Output USC0 (DAI0)  REF_CLK_13M  O USC1 (DAI1)  Reserved for future use  I USC2 (DAI2)  REF_CLK_8K (Bit clock slave)  O USC3 (DAI3)  BITCLK  I USC4 (DAI4)  FS_IN (Frame sync slave)  I USC5 (DAI5)  RXDAI  I USC6 (DAI6)  TXDAI  O   To clock input and output PCM samples the PCM interface requires a clock (BITCLK) which is synchronous to the 26 MHz system clock. The customer application must be designed to generate this bit clock by a PLL circuit or a divider controlled by one of the two following reference clock signals:  •  REF_CLK_13M that is equal to the system clock of 13 MHz.  •  REF_CLK_8K that is an 8 kHz signal divided from the system clock.  The frequency of the bit clock can vary from 256 kHz to 2048 kHz. The PCM interface is slave for the bit clock and the frame sync signals generated by the external codec.    PCM interface of the GSM module BITCLK FS_IN REF_CLK8 TXDAI bitclk RXDAI REF_CLK13 PLL or divider + frame sync logicCodec frame sync RX_data TX_data e.g.  256kHz  Figure 24: PCM interface application
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 55 of 91  15.02.2005 The timing of a PCM short frame is shown in Figure 25. In PCM mode, 16-bit data are transferred in both directions at the same time. The duration of a frame sync pulse is one BITCLK period, starting at the rising edge of BITCLK. TXDAI data is shifted out at the next rising edge of BITCLK. The most significant bit is transferred first. Data transmitted from RXDAI of the internal application is sampled at the falling edge of BITCLK.   BITCLKTXDAIRXDAIFS_INMSB LSB116125µs Figure 25: PCM timing
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 56 of 91  15.02.2005 3.13 Control Signals 3.13.1 Synchronization Signal The synchronization signal serves to indicate growing power consumption during the transmit burst. The signal is generated by the SYNC pin (pin number 32). Please note that this pin can adopt three different operating modes which you can select by using the AT^SSYNC command: the mode AT^SSYNC=0 described below, and the two LED modes AT^SSYNC=1 or AT^SSYNC=2 described in [1] and Section 3.13.2.  The first function (factory default AT^SSYNC=0) is recommended if you want your application to use the synchronization signal for better power supply control. Your platform design must be such that the incoming signal accommodates sufficient power supply to the MC75 module if required. This can be achieved by lowering the current drawn from other components installed in your application.   The timing of the synchronization signal is shown below. High level of the SYNC pin indicates increased power consumption during transmission.  Figure 26: SYNC signal during transmit burst  *)  The duration of the SYNC signal is always equal, no matter whether the traffic or the access burst are active.  Transmit burst1 Tx   577 µs every 4.616 ms2 Tx 1154 µs every 4.616 ms300 µsSYNC signal*)Transmit burst1 Tx   577 µs every 4.616 ms2 Tx 1154 µs every 4.616 msSYNC signal*)t = TBD
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 57 of 91  15.02.2005 3.13.2  Using the SYNC Pin to Control a Status LED  As an alternative to generating the synchronization signal, the SYNC pin can be configured to drive a status LED that indicates different operating modes of the MC75 module. To take advantage of this function the LED mode must be activated with the AT^SSYNC command and the LED must be connected to the host application. The connected LED can be operated in two different display modes (AT^SSYNC=1 or AT^SSYNC=2). For details please refer to [1].  Especially in the development and test phase of an application, system integrators are advised to use the LED mode of the SYNC pin in order to evaluate their product design and identify the source of errors.  To operate the LED a buffer, e.g. a transistor or gate, must be included in your application. A sample cicuit is shown in Figure 27. Power consumption in the LED mode is the same as for the synchronization signal mode. For details see Table 16, SYNC pin.            Figure 27: LED Circuit (Example)
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 58 of 91  15.02.2005 4 Antenna Interface The RF interface has an impedance of 50. MC75 is capable of sustaining a total mismatch at the antenna connector or pad without any damage, even when transmitting at maximum RF power.   The external antenna must be matched properly to achieve best performance regarding radiated power, DC-power consumption, modulation accuracy and harmonic suppression. Matching networks are not included on the MC75 PCB and should be placed in the host application.   Regarding the return loss MC75 provides the following values in the active band: Table 10: Return loss in the active band State of module  Return loss of module  Recommended return loss of application Receive > 8dB  > 12dB  Transmit   not applicable   > 12dB  Idle < 5dB   not applicable  The connection of the antenna or other equipment must be decoupled from DC voltage. This is necessary because the antenna connector is DC coupled to ground via an inductor for ESD protection.  4.1 Antenna Installation To suit the physical design of individual applications MC75 offers two alternative approaches to connecting the antenna:  •  Recommended approach: U.FL-R-SMT antenna connector from Hirose assembled on the component side of the PCB (top view on MC75). See Section 4.3 for details. •  Antenna pad and grounding plane placed on the bottom side. See Section 4.2.  The U.FL-R-SMT connector has been chosen as antenna reference point (ARP) for the Siemens reference equipment submitted to type approve MC75. All RF data specified throughout this manual are related to the ARP. For compliance with the test results of the Siemens type approval you are advised to give priority to the connector, rather than using the antenna pad.  IMPORTANT: Both solutions can only be applied alternatively. This means, whenever an antenna is plugged to the Hirose connector, the pad must not be used. Vice versa, if the antenna is connected to the pad, then the Hirose connector must be left empty.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 59 of 91  15.02.2005 Module Antenna ormeasurementequipment50Ohm50OhmU.FL  PADZ Module  Antenna or measurement equipment 50Ohm  50OhmU.FL  Z PAD   Antenna connected to Hirose connector:    Antenna connected to pad:        Figure 28: Never use antenna connector and antenna pad at the same time   No matter which option you choose, ensure that the antenna pad does not come into contact with the holding device or any other components of the host application. It needs to be surrounded by a restricted area filled with air, which must also be reserved 0.8 mm in height.   PCB U.FL antenna connector RF section Antenna pad  Restricted area   Figure 29: Restricted area around antenna pad
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 60 of 91  15.02.2005 4.2 Antenna Pad The antenna can be soldered to the pad, or attached via contact springs. For proper grounding connect the antenna to the ground plane on the bottom of MC75 which must be connected to the ground plane of the application.  When you decide to use the antenna pad take into account that the pad has not been intended as antenna reference point (ARP) for the Siemens MC75 type approval. The antenna pad is provided only as an alternative option which can be used, for example, if the recommended Hirose connection does not fit into your antenna design.   Also, consider that according to the GSM recommendations TS 45.005 and TS 51.010-01 a 50 connector is mandatory for type approval measurements. This requires GSM devices with an integral antenna to be temporarily equipped with a suitable connector or a low loss RF cable with adapter.   To prevent damage to the module and to obtain long-term solder joint properties you are advised to maintain the standards of good engineering practice for soldering.  MC75 material properties: MC75 PCB:   FR4 Antenna pad:   Gold plated pad     4.2.1  Suitable Cable Types For direct solder attachment, we suggest to use the following cable types: •  RG316/U 50 Ohm coaxial cable  •  1671A 50 Ohm coaxial cable  Suitable cables are offered, for example, by IMS Connector Systems. For further details and other cable types please contact http://www.imscs.com.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 61 of 91  15.02.2005 4.3  Antenna Connector  MC75 uses an ultra-miniature SMT antenna connector supplied from Hirose Ltd. The product name is:  U.FL-R-SMT  The position of the antenna connector on the MC75 board can be seen in Figure 30.       Figure 30: Mechanical dimensions of U.FL-R-SMT connector  Table 11: Product specifications of U.FL-R-SMT connector Item  Specification  Conditions Ratings     Nominal impedance  50 Ω Rated frequency  DC to 3 GHz Operating temp:-40°c to + 90°C Operating humidity: max. 90% Mechanical characteristics     Female contact holding force 0.15 N min  Measured with a ∅ 0.475 pin gauge Repetitive operation  Contact resistance: Center 25 mΩ  Outside 15mΩ 30 cycles of insertion and disengagement Vibration  No momentary disconnections of 1 µs; No damage, cracks and looseness of parts Frequency of 10 to 100 Hz, single amplitude of 1.5 mm, acceleration of 59 m/s2, for 5 cycles in the direction of each of the 3 axes Shock  No momentary disconnections of 1 µs. No damage, cracks and looseness of parts. Acceleration of 735 m/s2, 11 ms duration for 6 cycles in the direction of each of the 3 axes Environmental characteristics Humidity resistance  No damage, cracks and looseness of parts. Insulation resistance:  100 MΩ min. at high humidity 500 MΩ min when dry Exposure to 40°C, humidity of 95% for a total of 96 hours Temperature cycle  No damage, cracks and looseness of parts. Contact resistance: Center 25 mΩ  Outside 15mΩ Temperature: +40°C → 5 to 35°C → +90°C → 5 to 35°C Time: 30 min. → within 5 min. → 30 min. within 5 min Salt spray test  No excessive corrosion  48 hours continuous exposure to 5% salt water
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 62 of 91  15.02.2005 Table 12: Material and finish of U.FL-R-SMT connector and recommended plugs Part  Material  Finish Shell  Phosphor bronze  Silver plating Male center contact   Brass  Gold plating Female center contact   Phosphor bronze  Gold plating Insulator Plug:  PBT Receptacle: LCP Black Beige   Mating plugs and cables can be chosen from the Hirose U.FL Series. Examples are shown below and listed in Table 13. For latest product information please contact your Hirose dealer or visit the Hirose home page, for example http://www.hirose.com.   Figure 31: U.FL-R-SMT connector with U.FL-LP-040 plug   Figure 32: U.FL-R-SMT connector with U.FL-LP-066 plug
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 63 of 91  15.02.2005 In addition to the connectors illustrated above, the U.FL-LP-(V)-040(01) version is offered as an extremely space saving solution. This plug is intended for use with extra fine cable (up to ∅ 0.81 mm) and minimizes the mating height to 2 mm. See Figure 33 which shows the Hirose datasheet.    Figure 33: Specifications of U.FL-LP-(V)-040(01) plug
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 64 of 91  15.02.2005 Table 13: Ordering information for Hirose U.FL Series Item  Part number   HRS number Connector on MC75  U.FL-R-SMT   CL331-0471-0-10 Right-angle plug shell for ∅ 0.81 mm cable U.FL-LP-040 CL331-0451-2 Right-angle plug for  ∅ 0.81 mm cable U.FL-LP(V)-040 (01)  CL331-053-8-01 Right-angle plug for  ∅  1.13 mm cable U.FL-LP-068 CL331-0452-5 Right-angle plug for  ∅  1.32 mm cable U.FL-LP-066 CL331-0452-5 Extraction jig  E.FL-LP-N  CL331-04441-9
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 65 of 91  15.02.2005 5  Electrical, Reliability and Radio Characteristics 5.1  Absolute Maximum Ratings The absolute maximum ratings stated in Table 14 are stress ratings. Stresses beyond any of these limits will cause permanent damage to MC75.   Table 14: Absolute maximum ratings Parameter  Min  Max  Unit Supply voltage BATT+  -0.3  5.5  V Voltage at digital pins   -0.3  3.05   V Voltage at analog pins   -0.3  3.0  V Voltage at digital / analog pins in Power-down mode  TBD  TBD  V Voltage at VCHARGE pin  -0.3  5.5  V Voltage at CHARGEGATE pin  -0.3  5.5  V VUSB_IN -0.3 5.5 V VSENSE  5.5 V ISENSE  5.5 V   5.2 Operating Temperatures Test conditions were specified in accordance with IEC 60068-2 (still air). The values stated below are in compliance with GSM recommendation TS 51.010-01.  Table 15: Operating temperatures Parameter  Min  Typ  Max  Unit Ambient temperature (according to GSM 11.10)  -30  +25  +65  °C Automatic shutdown   MC75 board temperature   Battery temperature  -30 -20  --- ---  +90 +60  °C Ambient temperature for charging (software controlled fast charging) 0 --- +45 °C
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 66 of 91  15.02.2005 5.3  Pin Assignment and Signal Description The Molex board-to-board connector on MC75 is an 80-pin double-row receptacle. The names and the positions of the pins can be seen from Figure 1 which shows the top view of MC75.    1  GND  GND  80 2  nc  Do not use  79 3  nc  PWR_IND  78 4  GND  Do not use 77 5  Do not use Do not use 76 6  SD_WP  Do not use  75 7  Do not use  SD_D3  74 8  SD_DETECT  SD_D2  73 9  SD_CMD  SD_D1  72 10  SD_CLK  SD_D0  71 11  I2CCLK  I2CDAT  70 12  VUSB_IN  USB_DP  69 13  USC5  USB_DN  68 14  ISENSE  VSENSE  67 15  USC6  VMIC  66 16  CCCLK  EPN2  65 17  CCVCC  EPP2  64 18  CCIO  EPP1  63 19  CCRST  EPN1  62 20  CCIN  MICN2  61 21  CCGND  MICP2  60 22  USC4  MICP1  59 23  USC3  MICN1  58 24  USC2  AGND  57 25  USC1  IGT  56 26  USC0  EMERG_RST  55 27  BATT_TEMP  DCD0  54 28  SYNC  CTS1  53 29  RXD1  CTS0  52 30  RXD0  RTS1  51 31  TXD1  DTR0  50 32  TXD0  RTS0  49 33  VDDLP  DSR0  48 34  VCHARGE  RING0  47 35  CHARGEGATE  VEXT  46 36  GND  BATT+  45 37  GND  BATT+  44 38  GND  BATT+  43 39  GND  BATT+  42 40  GND  BATT+  41   Figure 34: Pin assignment (component side of MC75)
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 67 of 91  15.02.2005 Please note that the reference voltages listed in Table 16 are the values measured directly on the MC75 module. They do not apply to the accessories connected.  Table 16: Signal description Function  Signal name  IO  Signal form and level  Comment VImax = 4.3V VItyp = 3.8V VImin = 3.2V during Tx burst on board  I  2A, during Tx burst          Power supply BATT+ I n Tx = n x  577µs peak current every 4.616ms  Five pins of BATT+ and GND must be connected in parallel for supply purposes because higher peak currents may occur. Minimum voltage must not fall below 3.2V including drop, ripple, spikes.  Power supply GND  Ground  Application Ground VCHARGE I VImin = 1.015 * VBATT+ VImax = 5.45V This line signalizes to the processor that the charger is connected. If unused keep pin open. BATT_TEMP I Connect NTC with RNTC  10kΩ @ 25°C to ground. See Section 3.4.1 for B value of NTC.  Battery temperature measurement via NTC resistance. NTC should be installed inside or near battery pack to enable proper charging and deliver temperature values. If unused keep pin open. ISENSE I VImax = 4.65V  ∆VImax to VBATT+ = +0.3V at normal condition ISENSE is required for measuring the charge current. For this purpose, a shunt resistor for current measurement needs to be connected between ISENSE and VSENSE. If unused connect pin to VSENSE. VSENSE I VImax = 4.5V  VSENSE must be directly connected to BATT+ at battery connector or external power supply. Charge  Interface CHARGEGATE O VOmax = 5.5V IOmax = 1mA Control line to the gate of charge FET If unused keep pin open. External supply voltage VEXT O Normal mode: VOmin  = 2.75V VOtyp = 2.93V VOmax = 3.05V IOmax = -50mA   VEXT may be used for application circuits, for example to supply power for an SD Card.  If unused keep pin open. Not available in Power-down mode. The external digital logic must not cause any spikes or glitches on voltage VEXT.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 68 of 91  15.02.2005 Function  Signal name  IO  Signal form and level  Comment Power indicator PWR_IND[SE10] O VIHmax = 10V VOLmax = 0.4V at Imax = 2mA PWR_IND (Power Indicator) notifies the module’s on/off state.  PWR_IND is an open collector that needs to be connected to an external pull-up resistor. Low state of the open collector indicates that the module is on. Vice versa, high level notifies the Power-down mode. Therefore, the pin may be used to enable external voltage regulators which supply an external logic for communication with the module, e.g. level converters.  Ignition IGT  I RI  30kΩ, CI  10nF  VILmax = 0.8V at Imax = -150µA VOHmax = 4.5V (VBATT+) ON ~~~|____|~~~  Active Low ≥ 300ms  This signal switches the mobile on. This line must be driven low by an open drain or open collector driver.  Emergency reset  EMERG_RST I RI  5kΩ VILmax = 0.2V at Imax = -0.5mA VOHmin = 1.75V VOHmax = 3.05V  Signal    ~~~|______|~~~ Pull down ≥ 10ms Falling edge resets module.  Reset function in case of emergency: Pull down and release EMERG_RST. Falling edge will reset the module. Data stored in the volatile memory will be lost. For orderly software controlled reset rather use the AT+CFUN command (e.g. AT+CFUN=,1).  This line must be driven by open drain or open collector. If unused keep pin open.  VOLmax = 0.3V at I = 0.1mA VOHmin = 2.3V at I = -0.1mA VOHmax = 0.05V                Synchroni-zation SYNC   O n Tx = n x 577µs impulse each 4.616ms, with ___µs forward time.  There are two alternative options for using the SYNC pin: a) Indicating increased current consumption during uplink transmission burst. Note that the timing of the signal is different during handover.  b) Driving a status LED to indicate different operating modes of MC75. The LED must be installed in the host application. If unused keep pin open. RTC backup  VDDLP  I/O  RI  1k  VOmax = 4.5V VBATT+ = 4.3V: VO = 3.2V at IO = -500µA  VBATT+ = 0V: VI = 2.7V…4.5V at Imax= 15µA  If unused keep pin open.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 69 of 91  15.02.2005 Function  Signal name  IO  Signal form and level  Comment CCIN I RI  100kΩ VILmax = 0.6V at I = -25µA VIHmin = 2.1V at I = -10µA,  VOmax= 3.05V CCRST O RO  47Ω  VOLmax = 0.25V at I = +1mA VOHmin = 2.5V at I = -0.5mA VOHmax = 2.95V CCIO I/O RI  4.7kΩ VILmax = 0.75V VILmin = -0.3V VIHmin = 2.1V VIHmax = CCVCCmin + 0.3V = 3.05V  RO  100Ω VOLmax = 0.3V at I = +1mA VOHmin = 2.5V at I = -0.5mA VOHmax = 2.95V CCCLK O RO  100Ω VOLmax = 0.3V at I = +1mA VOHmin = 2.5V at I = -0.5mA VOHmax = 2.95V CCVCC O VOmin = 2.75V,  VOtyp = 2.85V VOmax = 2.95V IOmax = -20mA SIM interface specified for use with 3V SIM card CCGND  Ground  CCIN = Low, SIM card holder closed  Maximum cable length or copper track 100mm to SIM card holder.   All signals of SIM interface are protected against ESD with a special diode array.  Usage of CCGND is mandatory.  CCIN I RI  100kΩ VILmax = 0.6V at I = -25µA VIHmin = 2.1V at I = -10µA,  VOmax= 3.05V CCRST O RO  47Ω  VOLmax = 0.25V at I = +1mA VOHmin = 1.45V at I = -0.5mA VOHmax = 1.90V CCIO I/O RI  4.7kΩ VILmax = 0.45V VIHmin = 1.35V VIHmax = CCVCCmin + 0.3V = 2.00V  RO  100Ω VOLmax = 0.3V at I = +1mA VOHmin = 1.45V at I = -0.5mA VOHmax = 1.90V CCCLK O RO  100Ω VOLmax = 0.3V at I = +1mA VOHmin = 1.45V at I = -0.5mA VOHmax = 1.90V CCVCC O VOmin = 1.70V,  VOtyp = 1.80V VOmax = 1.90V IOmax = -20mA SIM interface specified for use with 1.8V SIM card CCGND  Ground CCIN = Low, SIM card holder closed  Maximum cable length or copper track 100mm to SIM card holder.   All signals of SIM interface are protected against ESD with a special diode array.  Usage of CCGND is mandatory. ASC0 Serial interface RXD0 TXD0 CTS0 RTS0 DTR0 DCD0 DSR0 RING0 O I O I I O O O VOLmax = 0.2V at I = 2mA VOHmin = 2.55V at I = -0.5mA VOHmax = 3.05V  VILmax = 0.8V VIHmin = 2.0V,  VIHmax = VEXTmin + 0.3V = 3.05V Serial interface for AT commands or data stream.  If lines are unused keep pins open.
MC75 Hardware Interface Description Strictly confidential / Draft  s MC75_V00.190a  Page 70 of 91  15.02.2005 Function  Signal name  IO  Signal form and level  Comment ASC1 Serial interface RXD1 TXD1 CTS1 RTS1  O I O I  VOLmax = 0.2V at I = 2mA VOHmin = 2.55V at I = -0.5mA VOHmax = 3.05V  VILmax = 0.8V VIHmin = 2.0V VIHmax = VEXTmin + 0.3V = 3.05V  Serial interface for AT commands or data stream.  If lines are unused keep pins open.  I2CCLK O VOLmax = 0.2V at I = 2mA VOHmin = 2.55V at I = -0.5mA VOHmax = 3.05V I2C interface I2CDAT I/O VOLmax = 0.2V at I = 2mA  VILmax = 0.8V VIHmin = 2.0V VIHmax = VEXTmin + 0.3V = 3.05V I2CDAT is configured as Open Drain and needs a pull-up resistor in the host application. According to the I2C Bus Specification Version 2.1 for the fast mode a rise time of max. 300ns is permitted. There is also a maximum VOL=0.4V at 3mA specified.  The value of the pull-up depends on the capacitive load of the whole system (I2C Slave + lines). The maximum sink current of I2CDAT and I2CCLK is 4mA. If lines are unused keep pins open. VUSB_IN I VINmin = 4.0V VINmax = 5.25V USB_DN I/O USB USB_DP I/O Differential Output Crossover voltage Range  VCRSmin = 1.5V, VCRSmax = 2.0V  Driver Output Resistance  ZDRVtyp = 32 Ohm  If lines are unused keep pins open. SD_D0 SD_D1 SD_D2 SD_D3 I/O SD_CLK O SD_WP I SD_CMD O SD card interface SD_DETECT I VOLmax = 0.2V at I = 2mA VOHmin = 2.55V at I = -0.5mA VOHmax = 3.05V  VILmax = 0.8V VIHmin = 2.0V VIHmax = VEXTmin + 0.3V = 3.05V  SD card interface can be connected to VEXT of MC75 or to external power supply. Rise and fall time of SD_CLK signal: max. 10ns. If lines are unused keep pins open. USC0 (DAI0)  O USC1 (DAI1)  I USC2 (DAI2)  O USC3 (DAI3)  I USC4 (DAI4)  I USC5 (DAI5)  I Digital Audio interface USC6 (DAI6)  O VOLmax = 0.2V at I = 2mA VOHmin = 2.55V at I = -0.5mA VOHmax = 3.05V  VILmax = 0.8V VIHmin = 2.0V VIHmax = VEXTmin + 0.3V = 3.05V  See Table 9 for details. If unused keep pins open.

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