TC65 Terminal Hardware Interface Description
Confidential / Released
s
TC65 Terminal_HD_V02.000b
Page 30 of 65
2007-02-19
3.7 Audio
Interface
The audio interface provides one analog input for a microphone and one analog output for
an earpiece.
•
The microphone input and the earpiece output are balanced.
•
For electret microphones a supply source is implemented.
•
The microphone supply characteristics are optimized for the recommended Votronic
handset. For ordering Information see Chapter 7.
•
This handset has been used for the reference handset for type approval. An extra
approval must be obtained for integrating other handsets or amplifiers.
The amplification of sending direction, receiving direction and sidetone depends on the
current audio mode.
EMC immunity complies with the vehicular environment requirements according to
EN 301 489-7.
1 2 3 4
Pin assignment
1 - MICN (Microphone - )
4 - MICP (Micr )
2 - EPN (Earpiece)
3 - EPP (Earpiece)
Figure 7: Audio Western plug (4-pole female)
- ... 0dB
0dB...42dB in steps
of 6dB
8
-18dB ... 0dB in steps
of 6dB
A
D
A
D
Speech
decoder
Speech
coder
MIC
EP
<outBbcGain>
<outCalibrate[n]>
n = 0, ..., 4
Microphone
Feeding
<sideTone>
AT parameters are given in brackets <...>
and marked red and italic.
<inBbcGain>
- ... 0dB
8
<inCalibrate>
Figure 8: Audio block diagram
