Specifications

XT55 Hardware Interface Description
Confidential / Preliminary
s
mo b i l e
XT55_hd_v00.02 Page 4 of 116 17.03.2004
3.6.5 Timing of the GSM_CTS signal in CYCLIC SLEEP modes...................48
3.6.6 Wake up XT55 from SLEEP mode.......................................................50
3.7 Summary of state transitions (except SLEEP mode)..........................................52
3.8 RTC backup for GSM/GPRS part of XT55 .........................................................53
3.9 Serial interfaces of the XT55 GSM/GPRS part...................................................54
3.9.1 Features supported on the first serial interface of GSM/GPRS part
(ASC0) .................................................................................................54
3.9.2 Features supported on the second serial interface of GSM/GPRS part
(ASC1) .................................................................................................55
3.9.3 ASC0 and ASC1 configuration .............................................................55
3.10 Audio interfaces .................................................................................................56
3.10.1 Microphone circuit ................................................................................57
3.10.2 Speech processing...............................................................................58
3.10.3 DAI timing.............................................................................................58
3.11 SIM interface......................................................................................................60
3.11.1 Requirements for using the GSM_CCIN pin .........................................61
3.11.2 Design considerations for SIM card holder ...........................................62
3.12 Control signals ...................................................................................................63
3.12.1 Inputs 63
3.12.2 Outputs 64
3.12.2.1 Synchronization signal..........................................................64
3.12.2.2 Using the GSM_SYNC pin to control a status LED...............65
3.12.2.3 Behavior of the GSM_RING0 line (ASC0 interface only) ......66
4 GPS application interface.........................................................................................68
4.1 Theory of operation............................................................................................68
4.2 Technical data....................................................................................................69
4.3 GPS operating modes........................................................................................70
4.3.1 Trickle Power mode..............................................................................71
4.3.2 Comparision of Trickle Power and Push-to Fix mode ...........................72
4.4 Power supply of the XT55 GPS part ..................................................................73
4.5 General purpose input/output.............................................................................73
4.6 Serial interfaces of the XT55 GPS part ..............................................................74
4.7 GPS control signals............................................................................................74
4.8 Receiver architecture .........................................................................................75
4.9 Operation procedure ..........................................................................................76
4.10 Start-up procedures ...........................................................................................77
4.10.1 Coldstart 77
4.10.2 Warmstart ............................................................................................77
4.10.3 Hotstart 77
5 GSM and GPS antenna interfaces............................................................................78
5.1 GSM antenna installation ...................................................................................78
5.1.1 GSM antenna connector.......................................................................78
5.1.2 GSM antenna pad ................................................................................80
5.2 Installing the GPS antenna ................................................................................80
5.3 Hirose antenna connector ..................................................................................81
6 Electrical, reliability and radio characteristics .......................................................85
6.1 Absolute maximum ratings.................................................................................85
6.2 Operating temperatures .....................................................................................85
6.3 Pin description ...................................................................................................86
6.4 Power supply ratings..........................................................................................92
6.5 Current consumption during GSM/GPRS transmit burst ....................................94