Analog Audio Interface - MTX -4G-JAVA-IoT Hardware User's Manual

8. Analog audio interface

Those MTX-Java-IoT models ordered with Audio option (A) have a 6-way 4-pole RJ connector, as shown
below, allowing a telephone handset to be plugged into the modem and giving access to the microphone
and earpiece signals. The connector may also be used to drive other analog 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-Java-IoT 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
1 2 3 4 5 6
PIN SIGNAL
1 NC
2 MICN
3 EPN
4 EPP
5 MICP
6 NC
MTX-Java-IoT | 2018/2
MTX © by MATRIX ELECTRONICA S.L.U.
SUPPORT: iotsupport@mtxm2m.com | SALES: info@mtxm2m.com |
DIRECTION DESCRIPTION
Input Microphone negative input
Output Earpiece negative output
Output Earpiece positive output
Input Microphone positive input
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