User's Manual

LE920A4 HW User Guide
Doc#: 1VV0301261
Rev. 4.3 Page 6 of 123 2017-12-07
4.3.6. SD Card Pads @ 2.95V .................................................................................44
4.3.7. SIM Card Pads @2.95V.................................................................................44
5. HARDWARE COMMANDS ........................................................................... 46
Turning on the Module ...................................................................................46
Initialization and Activation State ...................................................................46
Turning off the Module ...................................................................................48
5.3.1. Shutdown by Software Command ..................................................................49
5.3.2. Hardware Shutdown ......................................................................................49
5.3.3. Unconditional Hardware Reset ......................................................................51
5.3.4. Unconditional Hardware Shutdown ................................................................52
6. POWER SUPPLY .......................................................................................... 54
Power Supply Requirements ..........................................................................54
General Design Rules ....................................................................................56
6.2.1. Electrical Design Guidelines ..........................................................................56
6.2.1.1. + 5V Input Source Power Supply Design Guidelines ......................................56
6.2.1.2. + 12V Input Source Power Supply Design Guidelines ....................................57
6.2.1.3. Battery Source Power Supply Design Guidelines ...........................................59
6.2.2. Thermal Design Guidelines ............................................................................59
6.2.3. Power Supply PCB Layout Guidelines ...........................................................60
7. ANTENNA(S) ................................................................................................ 62
GSM/WCDMA/TD-SCDMA/LTE Antenna Requirements ...............................62
GSM/WCDMA/TD-SCDMA/LTE Antenna – PCB Line Guidelines ..................63
GSM/WCDMA/TD-SCDMA/LTE Antenna – Installation Guidelines ................64
Antenna Diversity Requirements ....................................................................64
GPS/GNSS Antenna Requirements ...............................................................65
7.5.1. Combined GPS/GNSS Antenna .....................................................................65
7.5.2. Linear and Patch GPS/GNSS Antenna ..........................................................66
7.5.3. Front End Design Considerations ..................................................................66
7.5.4. GPS/GNSS Antenna – PCB Line Guidelines .................................................66
7.5.5. GPS/GNSS Antenna – Installation Guidelines ...............................................67
8. HARDWARE INTERFACES .......................................................................... 68
USB Port........................................................................................................69
8.1.1. USB OTG support ..........................................................................................70
HSIC Interface ...............................................................................................70
Ethernet Connectivity (optional) .....................................................................71
8.3.1. SGMII Interface..............................................................................................71
8.3.2. Ethernet Control Interface ..............................................................................71