3

Abbreviations .......................................................................................

22

Integrating the Wireless Modem .................................................................

24

4

Mechanical Description.........................................................................

25

4.1

INTERFACE DESCRIPTION ........................................................................................

25

4.2

PHYSICAL DIMENSIONS ...........................................................................................

27

5

System Connector Interface..................................................................

29

5.1

OVERVIEW ..............................................................................................................

29

5.2

DEALING WITH UNUSED PINS...................................................................................

32

5.3

GENERAL ELECTRICAL AND LOGICAL CHARACTERISTICS..........................................

34

5.3.1

LEVEL SHIFTER INTERFACES..............................................................................

34

5.3.1.1 COMMON LEVEL SHIFTER INTERFACE ............................................................

34

5.3.1.2 I2C LEVEL SHIFTER INTERFACE......................................................................

36

5.4

GROUNDS...............................................................................................................

37

5.4.1

ANALOGUE GROUND (AREF) .............................................................................

37

5.4.2

COMMON GROUND (GND)................................................................................

37

5.5

REGULATED POWER SUPPLY INPUT (VCC).................................................................

38

5.6

VOLTAGE REFERENCE (VREF) ...................................................................................

39

5.6.1 VREF AS AN OUTPUT........................................................................................

39

5.6.2 VREF AS AN INPUT ...........................................................................................

39

5.7

BATTERY CHARGING INPUT (CHG_IN) ......................................................................

41

5.7.1

CHARGING PROCESS ........................................................................................

42

5.7.2

SERIES DIODE...................................................................................................

43

5.7.3

BATTERY SELECTION........................................................................................

43

5.8

POWERING THE MODULE ON AND OFF (ON/OFF) .....................................................

47

5.8.1 TURNING THE MODULE ON ..............................................................................

47

5.8.2 TURNING THE MODULE OFF .............................................................................

48

5.9

ANALOGUE AUDIO ..................................................................................................

50

5.9.1 AUXILIARY AUDIO TO MOBILE STATION (AUXI)..................................................

51

5.9.2 AUXILIARY AUDIO FROM MOBILE STATION (AUXO)............................................

52

5.9.3 MICROPHONE SIGNALS (MICIP, MICIN) ..............................................................

52

5.9.4 SPEAKER SIGNALS (EARP, EARN) .......................................................................

53

5.10

 

PCM DIGITAL AUDIO (SSP) ...................................................................................

53

 

 

LZT 123 1834

4