L
LE920 Hardware User Guide
1vv0301026 Rev.0 - draft4 – 2013-05-
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights Reserved.
Page 6 of 76
4.3.2.
Hardware Shutdown ...................................................................................................... 29
4.3.3.
Hardware Unconditional Restart ................................................................................... 30
4.3.4.
Hardware Unconditional Shutdown ............................................................................... 31
4.4.
Summary of Turning ON and OFF the module .......................................................... 32
5.
Power Supply ....................................................................................................... 33
5.1.
Power Supply Requirements ..................................................................................... 33
5.2.
General Design Rules ................................................................................................ 35
5.2.1.
Electrical Design Guidelines .......................................................................................... 35
5.2.1.1.
+ 5V Input Source Power Supply Design Guidelines .............................................. 35
5.2.1.2.
+ 12V Input Source Power Supply Design Guidelines............................................. 36
5.2.1.3.
Battery Source Power Supply Design Guidelines ................................................... 38
5.2.2.
Thermal Design Guidelines............................................................................................ 39
5.2.3.
Power Supply PCB Layout Guidelines ........................................................................... 40
6.
Antenna(s) ........................................................................................................... 42
6.1.
GSM/WCDMA/LTE Antenna Requirements ............................................................... 42
6.2.
GSM/WCDMA/LTE Antenna – PCB line Guidelines ................................................... 43
6.3.
GSM/WCDMA/LTE Antenna – Installation Guidelines ............................................... 44
6.4.
Antenna Diversity Requirements ............................................................................... 44
6.5.
GPS/GNSS Antenna Requirements ........................................................................... 45
6.5.1.
Combined GPS/GNSS Antenna ...................................................................................... 45
6.5.2.
Linear and Patch GPS/GNSS Antenna ........................................................................... 46
6.5.3.
Front End Design Considerations .................................................................................. 46
6.5.4.
GPS/GNSS Antenna - PCB Line Guidelines ................................................................... 46
6.5.5.
GPS/GNSS Antenna – Installation Guidelines ............................................................... 47
7.
Logic Level Specifications .................................................................................... 48
8.
USB Port .............................................................................................................. 49
9.
Serial Ports .......................................................................................................... 50
9.1.
Modem Serial Port 1 .................................................................................................. 51
9.2.
Modem Serial Port 2 .................................................................................................. 52
9.3.
RS232 Level Translation ............................................................................................ 52
10.
Audio Section Overview ..................................................................................... 54
