User's Manual

GM862-QUAD / PY Hardware User Guide
1vv0300748 Rev. 1 - 24/10/06
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Right reserved page 3 of 70
6.4 Microphone Biasing .............................................................................................................43
6.4.1 Balanced Microphone Biasing ....................................................................................................... 43
6.4.2 Unbalanced Microphone Biasing...................................................................................................44
6.5 Microphone Buffering ..........................................................................................................46
6.5.1 Buffered Balanced Mic................................................................................................................... 46
6.5.2 Buffered Unbalanced (Single Ended) Microphone . ...................................................................... 48
7 OUTPUT LINES (Speaker)..............................................................................................51
7.1 Short Description. ................................................................................................................51
7.2 Output Lines Characteristics ..............................................................................................52
7.3 General Design Rules ..........................................................................................................53
7.3.1 Noise Filtering................................................................................................................................ 53
7.4 Handset Earphone Design...................................................................................................54
7.5 Hands-Free Earphone (Low Power) Design .......................................................................55
7.6 Car Kit Speakerphone Design .............................................................................................56
8 General Purpose I/O.......................................................................................................57
8.1 Logic level specifications ....................................................................................................57
8.2 Using a GPIO pin as INPUT .................................................................................................59
8.3 Using a GPIO pin as OUTPUT .............................................................................................59
8.4 Using the RFTXMON Output GPIO5....................................................................................59
8.5 Using the Alarm Output GPIO6 ...........................................................................................59
8.6 Using the Buzzer Output GPIO7..........................................................................................60
9 ADC section....................................................................................................................61
9.1 ADC converter ......................................................................................................................61
9.1.1 Description..................................................................................................................................... 61
9.1.2 Using ADC Converter .................................................................................................................... 61
10 Camera ............................................................................................................................62
10.1 Camera Transchip.............................................................................................................62
10.1.1 Camera Interface Connectors........................................................................................................ 62
10.1.2 EVB for Camera Support ............................................................................................................... 63
10.1.3 EVB for Transchip camera support ............................................................................................... 65
10.1.4 Block Diagram for supported camera ............................................................................................ 66
10.1.5 Schematic Diagrams for supported cameras ................................................................................ 67
10.1.6 Example usage script for camera .................................................................................................. 68
11 Conformity Assessment Issues....................................................................................69
12 Document Change Log ..................................................................................................70