User Guide

HE910 Hardware User Guide
1vv0300925 Rev.18 – 15-06-2012
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7.3.3 GPS Antenna Gain .................................................................................................................................................. 51
7.3.4 Active versus Passive Antenna ............................................................................................................................... 51
7.3.5 GPS Antenna - PCB Line Guidelines ........................................................................................................................ 52
7.3.6 RF Trace Losses....................................................................................................................................................... 52
7.3.7 Implications of the Pre-select SAW Filter ............................................................................................................... 53
7.3.8 External LNA Gain and Noise Figure....................................................................................................................... 53
7.3.9 Powering the External LNA (active antenna) ......................................................................................................... 53
7.3.10 External LNA Enable ............................................................................................................................................. 54
7.3.11 Shielding ............................................................................................................................................................... 55
7.3.12 GPS Antenna - Installation ................................................................................................................................... 55
8 LOGIC LEVEL SPECIFICATIONS .................................................................................................................................. 56
8.1 RESET SIGNAL .................................................................................................................................................................... 57
9 USB PORT ................................................................................................................................................................ 58
9.1 USB 2.0 HS ...................................................................................................................................................................... 58
10 SPI PORT ................................................................................................................................................................. 59
10.1 SPI CONNECTIONS ............................................................................................................................................................ 60
11 SERIAL PORTS .......................................................................................................................................................... 61
11.1 MODEM SERIAL PORT 1 (USIF0) ................................................................................................................................... 62
11.2 MODEM SERIAL PORT 2 (USIF1) ................................................................................................................................... 64
11.3 RS232 LEVEL TRANSLATION ................................................................................................................................................ 65
12 AUDIO SECTION OVERVIEW .................................................................................................................................... 67
12.1 ELECTRICAL CHARACTERISTICS ............................................................................................................................................. 67
12.1.1 CODEC Examples .................................................................................................................................................. 67
13 GENERAL PURPOSE I/O ........................................................................................................................................... 68
13.1 GPIO LOGIC LEVELS .......................................................................................................................................................... 69
13.2 USING A GPIO PAD AS INPUT ........................................................................................................................................... 70
13.3 USING A GPIO PAD AS OUTPUT ........................................................................................................................................ 70
13.4 INDICATION OF NETWORK SERVICE AVAILABILITY ..................................................................................................................... 71
13.5 RTC BYPASS OUT ............................................................................................................................................................. 72
13.6 EXTERNAL SIM HOLDER IMPLEMENTATION ........................................................................................................................... 72
13.7 VAUX POWER OUTPUT ..................................................................................................................................................... 72
13.8 ADC CONVERTER ............................................................................................................................................................. 73
13.8.1 Description ........................................................................................................................................................... 73
13.8.2 Using ADC Converter ............................................................................................................................................ 73
14 MOUNTING THE HE910 ON THE APPLICATION ........................................................................................................ 74
14.1 GENERAL ........................................................................................................................................................................ 74
14.2 MODULE FINISHING & DIMENSIONS ..................................................................................................................................... 74
14.3 RECOMMENDED FOOT PRINT FOR THE APPLICATION ................................................................................................................. 76
14.4 STENCIL .......................................................................................................................................................................... 77
14.5 PCB PAD DESIGN .............................................................................................................................................................. 77
14.6 PCB PAD DIMENSIONS ....................................................................................................................................................... 78
14.7 SOLDER PASTE .................................................................................................................................................................. 80