User Manual

DM15/25 Integrator’s Manual 17 OF 38
Pin DM-15/DM-25 Description
3 AFMS Audio Output From Module
6 ATMS Audio Input to Module
The factory default audio settings are presented in the following table. Refer to AT*NAUD
Module audio output
Output Impedance (active state)
Output Impedance (inactive state)
Output Impedance (pwr down state)
Drive capacity into 50 Ω
Drive capacity into 5 kΩ
(0.3 – 3.5 kHz)
Zout < 10 Ω in series with ≥3.3 uF
(-20%)
Zout < 10 Ω to VDD/2
Zout > 30 kΩ
1.1 V
P-P
min.
2.0 V
P-P
min./ 4.0 V
P-P
max.
External Device audio input Input
Impedance
Zin > 50 Ω
Volume control
± 12 dB from nominal > - 40 dB
(mute)
AFMS
Levels to external audio input at mid
volume
28 mVrms nominal 450 mVrms
max.
All sources must be AC coupled except for a microphone device. MIC
should be DC coupled in order for module to supply DC power to
microphone.
External audio source
Output impedance (active state)
Output impedance (inactive state)
Zout ≤ 100 Ω
Zout > 10 k
Module audio input
Input impedance
Output DC level unloaded for external
MIC
Zin > 2 kΩ
2.0 V min.
Levels from external audio source
(default)
45 mVrms nominal 340 mVrms
max.
ATMS
Audio input signal is amplified an
additional 32 db and a DC bias is
provided to the microphone when using
the AT*NAUD command for HF mode.
1.5 mVrms nominal
4.1.4.2 Digital Audio
The DM-15/DM-25 provides digital audio capability over the system connector. The digital audio
signals enable the connection of a digital audio source. The receiver is bypassing the analog audio
processing functions performed within the ME. The digital audio interface includes the following
PCM signals: