User's Manual

XT55/56 Hardware Interface Description
Confidential / Released
s
XT55/56_hd_v02.06a Page 3 of 125 17.12.2004
Contents
0 Document history..........................................................................................................8
1 Introduction .................................................................................................................11
1.1 Related documents..............................................................................................11
1.2 Terms and abbreviations .....................................................................................12
1.3 Type approval ......................................................................................................16
1.4 Safety precautions ...............................................................................................18
2 Product concept..........................................................................................................20
2.1 XT55/56 key features at a glance ........................................................................21
2.2 Circuit concept .....................................................................................................24
3 GSM application interface ..........................................................................................26
3.1 GSM/GPRS operating modes..............................................................................26
3.2 Power supply .......................................................................................................28
3.2.1 Power supply pins on the board-to-board connector .............................28
3.2.2 Minimizing power losses........................................................................29
3.2.3 Monitoring power supply........................................................................29
3.3 Power up / down scenarios..................................................................................30
3.3.1 Turn on the GSM part of XT55/56..........................................................30
3.3.1.1 Turn on the GSM part of XT55/56 using the ignition line
GSM_IGT (Power on) ............................................................31
3.3.1.2 Timing of the ignition process................................................32
3.3.1.3 Turn on the GSM part of XT55/56 using the
GSM_POWER signal.............................................................33
3.3.1.4 Turn on the GSM part of XT55/56 using the
RTC (Alarm mode).................................................................33
3.3.2 Turn off the GSM part of XT55/56..........................................................35
3.3.2.1 Turn off GSM part of the XT55/56 module using
AT command .........................................................................35
3.3.2.2 Emergency shutdown using GSM_EMERGOFF pin .............36
3.3.3 Automatic shutdown...............................................................................37
3.3.3.1 Temperature dependent shutdown........................................37
3.3.3.2 Temperature control during emergency call ..........................38
3.3.3.3 Undervoltage shutdown if battery NTC is present .................38
3.3.3.4 Undervoltage shutdown if no battery NTC is present ............39
3.3.3.5 Overvoltage shutdown ...........................................................39
3.4 Automatic GPRS Multislot Class change.............................................................40
3.5 Charging control of the GSM part ........................................................................41
3.5.1 Battery pack characteristics...................................................................43
3.5.2 Recommended battery pack specification .............................................44
3.5.3 Implemented charging technique...........................................................45
3.5.4 Operating modes during charging..........................................................46
3.5.5 Charger requirements ............................................................................47
3.6 Power saving .......................................................................................................48
3.6.1 No power saving (AT+CFUN=1) ............................................................48
3.6.2 NON-CYCLIC SLEEP mode (AT+CFUN=0)..........................................48
3.6.3 CYCLIC SLEEP mode (AT+CFUN=5, 6, 7, 8) .......................................48
3.6.4 CYCLIC SLEEP mode AT+CFUN=9 .....................................................49
3.6.5 Timing of the GSM_CTS signal in CYCLIC SLEEP modes ...................49
3.6.6 Wake up XT55/56 from SLEEP mode ...................................................51