Owner's manual

GM862-GPS Hardware User Guide
1vv0300728 Rev. 8 - 20/09/07
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 2 of 73
Contents
1 Overview ........................................................................................................................... 7
2 Dimensions ....................................................................................................................... 8
3 Interface connectors on GM862-GPS ............................................................................. 9
3.1 Description .............................................................................................................................. 9
3.2 Connectors Position .............................................................................................................. 9
3.3 Board to Board Connector .................................................................................................. 10
3.3.1 Molex 52991-0508 (male) GM862 Connector PIN-OUT ................................................................11
3.4 Antenna Connectors ............................................................................................................ 13
4 Antenna ........................................................................................................................... 14
4.1 GSM Antenna Requirements ............................................................................................... 14
4.2 GSM Antenna - Installation Guidelines .............................................................................. 15
4.3 GPS Antenna Requirements ................................................................................................ 15
4.4 GPS Antenna - Installation Guidelines ............................................................................... 16
4.5 Logic level specifications .................................................................................................... 17
4.5.1 Reset signal ....................................................................................................................................18
5 Hardware Commands .................................................................................................... 19
5.1 Turning ON the GM862-GPS ................................................................................................ 19
5.2 Turning OFF the GM862-GPS .............................................................................................. 21
5.2.1 Hardware Shutdown .......................................................................................................................21
5.2.2 Hardware Unconditional Shutdown ................................................................................................22
6 Power Supply ................................................................................................................. 24
6.1 Power Supply Requirements ............................................................................................... 24
6.2 General Design Rules .......................................................................................................... 26
6.2.1 Electrical Design Guidelines ...........................................................................................................26
6.2.1.1 + 5V input Source Power Supply Design Guidelines .................................................................26
6.2.1.2 + 12V Input Source Power Supply Design Guidelines ...............................................................28
6.2.1.3 Battery Source Power Supply Design Guidelines ......................................................................30
6.2.1.4 Battery Charge control Circuitry Design Guidelines ...................................................................31
6.2.2 Thermal Design Guidelines ............................................................................................................33
6.2.3 Power Supply PCB layout Guidelines ............................................................................................34
7 Serial Ports ..................................................................................................................... 35
7.1 Level translation ................................................................................................................... 37
7.2 5V UART level translation .................................................................................................... 39
8 Audio Section Overview ................................................................................................ 41