EGS5 Hardware Interface Description
5.7 Electrical Characteristics of the Voiceband Part
104
EGS5_HD_v02.004
Page 99 of 123
2012-02-09
Confidential / Released
5.7.3
Characteristics of Audio Modes
The electrical characteristics of the voiceband part depend on the current audio mode set with
the AT^SNFS command. All values are noted for default gains e.g. all parameters of AT^SNFI
and AT^SNFO are left unchanged.
Note: With regard to acoustic shock, the cellular application must be designed to avoid sending
false AT commands that might increase amplification, e.g. for a highly sensitive earpiece. A
protection circuit should be implemented in the cellular application.
Table 32:
Voiceband characteristics (typical)
Audio mode no.
AT^SNFS=
1 (Default
settings,
not adjust-
able)
2
3
4
5
6
Name
Default
Handset
Basic
Handsfree
Headset
User
Handset
Plain
Codec 1
DTMF
Purpose
DSB with
Votronic
handset
Car Kit
Headset
DSB with
individual
handset
Direct
access to
speech
coder
Tip and Ring
interface for
DTMF end-
to-end trans-
mission
Gain setting via AT
command. Defaults:
inBbcGain
outBbcGain
Fix
5
2
Adjustable
2
2
Adjustable
5
1
Adjustable
5
2
Adjustable
0
1
Adjustable
1
1
Default audio inter-
face
1
2
2
1
1
2
Power supply VMIC ON
ON ON
ON
ON
ON
Sidetone
Fix
---
Adjustable Adjustable Adjustable
Adjustable
Volume control
Fix
Adjustable Adjustable Adjustable Adjustable
Adjustable
Echo canceller
ON
ON
ON
ON
OFF
ON
Noise reduction
6dB
12dB
12dB
6dB
OFF
OFF
MIC input signal for
0dBm0
1
-10dBm0
f=1024 Hz
1.
All values measured before the noise reduction attenuates the sine wave after a few seconds.
16mV
5mV
---
2
90mV
2.
0dBm0 cannot be achieved at 1024Hz due to attenuation of the frequency correction filter for the sending
direction at this frequency.
18mV
16mV
16mV
5mV
400mV
126mV
200mV
63mV
EP output signal in
mV rms. @ 0dBm0,
1024 Hz, no load
(default gain) /
@ 3.14 dBm0
660mV
240mV
default @
max vol-
ume
740mV
default @
max vol-
ume
660mV
default @
max vol-
ume
1.47V
Vpp = 6.2V
735mV
Vpp=3.1
3
V
3.
Output voltage is limited to 4.2V.
Sidetone gain at
default settings
21dB
-
dB
10.0dB
21dB
-
dB
-
dB
