MIX Modem - GSM
User Manual V.1.1
Pag. 15
Subject to change without prior notice
3.2 Audio Connector
A 6-way 4-poles RJ connector, as shown below, allows a telephone handset to be plugged into the
modem, giving access to the microphone and earpiece signals. The connector may also be used to
drive other analogue audio sub-systems or devices.
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 MTX-63I/65I is pre-configured to work with a range of handsets, the audio interface is flexible
and its performance can be configured, using AT commands, to match a particular handset or audio
subsystem.
•
Earpiece outputs are short-circuit protected.
Audio handset connection.
Audio signal descriptions are listed below:
Pin Signal
Dir
Description
0
Not connected
1
MICN
I
Microphone negative
input
2
EPN
O
Earpiece
negative
output
3
EPP
O
Earpiece
positive
output
4
MICP
I
Microphone positive
input
5
Not connected
