Siemens MC45 User Manual

MC45 Hardware Interface Description
P R E L I M I N A R Y
MC45_HD_01_V00.02a Page 83 of 90 12.08.2002
6.5.3 Characteristics of audio modes
The electrical characteristics of the voiceband part depend on the current audio mode set
with the AT^SNFS command.
Table 31: Voiceband characteristics (typical), all values preliminary
Audio mode no.
AT^SNFS=
1 (Default
settings, not
adjustable)
2 3 4 5 6
Name Default
Handset
Basic
Handsfree
Headset User
Handset
Plain
Codec 1
Plain
Codec 2
Purpose DSB with
M20T hand-
set
Siemens Car
Kit Portable
Siemens
Headset
DSB with
individual
handset
Direct
access to
speech
coder
Direct
access to
speech
coder
Gain setting via AT
command. Defaults:
inBbcGain
outBbcGain
Fix
4 (24dB)
1 (-6dB)
Adjustable
2 (12dB)
1 (-6dB)
Adjustable
5 (30dB)
2 (-12dB)
Adjustable
4 (24dB)
1 (-6dB)
Adjustable
0 (0dB)
0 (0dB)
Adjustable
0 (0dB)
0 (0dB)
Default audio
interface
1 2 2 1 1 2
4)
Power supply ON ON ON ON OFF OFF
Sidetone ON --- Adjustable Adjustable Adjustable Adjustable
Volume control OFF Adjustable Adjustable Adjustable Adjustable Adjustable
Limiter (receive) ON ON ON ON --- ---
Compressor
(receive)
--- ON
1)
--- --- --- ---
AGC (send) --- --- ON --- --- ---
Echo control (send) Suppression Cancellation +
suppression
--- Suppres-
sion
--- ---
Noise suppression
2)
--- up to 10dB 10dB --- --- ---
MIC input signal for
0dBm0 @ 1024 Hz
(default gain)
23mV 58mV 7.5mV @
-3dBm0 due
to AGC
23mV 315mV 315mV
EP output signal in
mV rms. @ 0dBm0,
1024 Hz, no load
(default gain);
@ 3.14 dBm0
284mV 120mV
default @
max volume
300mV
default @
max volume
284mV
default @
max
volume
895mV
3.7Vpp
895mV
3.7Vpp
Sidetone gain at
default settings
22.8dB -$ dB Affected by
AGC, 13dB
@ 7.5mV
(MIC)
22.8dB 0dB
@
sideTone
= 8192
3)
0dB
@
sideTone
= 8192
3)
1)
Adaptive, receive volume increases with higher ambient noise level.
2)
In audio modes with noise reduction, the microphone input signal for 0dBm0 shall be measured
with a sine burst signal for a tone duration of 5 seconds and a pause of 2 sec. The sine signal
appears as noise and, after approx. 12 sec, is attenuated by the noise reduction by up to 10dB.
3)
See AT^SNFO command in [1].
4)
Audio mode 5 and 6 are identical. With AT^SAIC, you can easily switch mode 5 to the second
interface. Therefore, audio mode 6 is only kept for compatibility to earlier Siemens GSM products.

Siemens MC45 Specifications

General

Brand	Siemens
Model	MC45
Category	Engine
Language	English