Specifications

TC35 / TC37 Hardware Interface Description
TC35_37_HD_02_V03.10 - Released Page 3 of 92 21.12.2001
Contents
0 Version History........................................................................................................... 7
1 Introduction ................................................................................................................ 8
1.1 Scope of the document and related documents .................................................. 8
1.2 Terms and abbreviations..................................................................................... 9
1.3 Standards.......................................................................................................... 12
1.4 Safety Precautions ............................................................................................ 13
2 Functions overview .................................................................................................. 15
2.1 TC35 / TC37 key features at a glance............................................................... 16
2.2 Block diagram of TC35...................................................................................... 18
2.3 Block diagram of TC37...................................................................................... 19
2.4 GSM baseband processor................................................................................. 20
2.4.1 Features of the GSM baseband processor .......................................... 20
3 Application Interface ................................................................................................ 21
3.1 Operating modes............................................................................................... 22
3.2 Power supply..................................................................................................... 23
3.2.1 Minimizing power losses ...................................................................... 24
3.2.2 Battery pack......................................................................................... 25
3.2.2.1 Recommended battery pack ................................................................ 26
3.2.2.2 Supported charging technique ............................................................. 27
3.2.2.3 Operating modes during charging........................................................ 28
3.2.2.4 Charger requirements.......................................................................... 29
3.3 Power up / down scenarios................................................................................ 30
3.3.1 Turn on the GSM engine...................................................................... 30
3.3.1.1 Turn on GSM engine using the ignition line IGT (Power on) ................ 30
3.3.1.2 Timing of the ignition process .............................................................. 31
3.3.1.3 Turn on GSM engine using the POWER lines ..................................... 32
3.3.1.4 Turn on GSM engine using the RTC (Alarm mode) ............................. 32
3.3.2 Power saving ....................................................................................... 33
3.3.3 Wake up GSM engine.......................................................................... 33
3.3.4 Turn off GSM engine ........................................................................... 34
3.3.4.1 Turn off GSM engine using AT command............................................ 34
3.3.4.2 Emergency shutdown using /PD pin .................................................... 34
3.3.4.3 Automatic shutdown ............................................................................ 35
3.3.5 Summary of state transitions ............................................................... 37
3.4 RTC backup ...................................................................................................... 38
3.5 Serial interface .................................................................................................. 40
3.6 Audio interface .................................................................................................. 42
3.6.1 Speech processing .............................................................................. 43
3.7 SIM interface ..................................................................................................... 44
3.7.1 Approval considerations....................................................................... 44
3.7.2 Design considerations for SIM card holder .......................................... 45
3.7.3 Grounding the SIM interface ................................................................ 46
3.8 Control signals................................................................................................... 47
3.8.1 Inputs................................................................................................... 47
3.8.2 Outputs................................................................................................ 48
3.8.2.1 Synchronization signal ......................................................................... 48
3.8.2.2 Using the SYNC pin to control a status LED ........................................ 49