Specifications

AC65/AC75 Hardware Interface Description
5.7 Electrical Characteristics of the Voiceband Part
s
AC65_AC75_HD_v01.002 Page 93 of 117 2006-10-30
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 com-
mands that might increase amplification, e.g. for a highly sensitive earpiece. A protection circuit should be imple-
mented in the cellular application.
Table 31: Voiceband characteristics (typical)
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
VDA
Handsfree
Purpose
DSB with
Votronic
handset
Siemens
Car Kit Por-
table
Siemens
Headset
DSB with
individual
handset
Direct
access to
speech
coder
Sample VDA
adjustment
for mid-sized
station wagon
Gain setting via AT
command. Defaults:
inBbcGain
outBbcGain
Fix
5 (30dB)
1 (-6dB)
Adjustable
2 (12dB)
2 (-12dB)
Adjustable
5 (30dB)
1 (-6dB)
Adjustable
5 (30dB)
1 (-6dB)
Adjustable
0 (0dB)
0 (0dB)
Adjustable
2(12dB)
1 (-6dB)
Default audio inter-
face
12211
1
1.
AT^SAIC can be used to switch mode 5 to the second interface.
2
Power supply VMIC
ON ON ON ON ON ON
Sidetone
Fix --- 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 12dB
MIC input signal for
0dBm0
2
-10dBm0
f=1024 Hz
2.
All values measured before the noise reduction attenuates the sine wave after a few seconds.
16mV
5mV
---
3
90mV
3.
0dBm0 cannot be achieved at 1024Hz due to attenuation of the frequency correction filter for the headset at this
frequency
18mV
16mV
16mV
5mV
400mV
126mV
125mV
40mV
EP output signal in
mV rms. @ 0dBm0,
1024 Hz, no load
(default gain) /
@ 3.14 dBm0
660mV 240mV
default @
max volume
740mV
default @
max volume
660mV
default @
max volume
1.47V
Vpp = 6.2 V
720mV
default @
max volume
Sidetone gain at
default settings
21dB -∞ dB 10dB 21dB -∞ dB -∞ dB