Telit GE863-QUAD / GE863-PY
Hardware User guide
1vv0300715, Rev. ISSUE#0, - 21/02/06
Reproduction forbidden without Telit Communication written authorization – All Right reserved – Right of modification reserved
page 3 of 71
6
MICROPHONE 27
6.1
Microphone line Characteristic and requirements
27
6.2
General Design Rules
30
6.3
Microphone Biasing
30
6.3.1
Balanced Microphone biasing
31
6.3.2 Unbalanced
Microphone
biasing
33
6.4
Microphone buffering
34
6.4.1
Buffered Balanced Mic.
34
6.4.2
Buffered Unbalanced (Single Ended) Mic.
37
7
SPEAKER 40
7.1
Speaker lines characteristics and requirements
40
7.2
General Design rules
42
7.2.1 Noise
Filtering
43
7.3
Handset earphone design
43
7.4
Hands Free earphone (low power) design
45
7.5
Car Kit speakerphone design
45
8
GENERAL PURPOSE I/O
47
8.1
Using a GPIO pad as INPUT
47
8.2
Using a GPIO pad as OUTPUT
47
8.3
Using the Alarm Output GPIO6
48
8.4
Using the Buzzer Output GPIO7
48
9
CAMERA 49
9.1
Transchip Camera
49
9.1.1
Camera interface connectors
49
9.1.2
EVB for Transchip camera support
52
9.1.3
Block Diagram for supported cameras
53
9.1.4
Schematic Diagrams for supported cameras
54
9.1.5
Example usage script for camera
55
