Specifications
AC65/AC75 Hardware Interface Description
5.7 Electrical Characteristics of the Voiceband Part
s
AC65_AC75_HD_v01.002 Page 95 of 117 2006-10-30
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gs = gain setting
5.7.5 Voiceband Transmit Path
Test conditions:
• The values specified below were tested to 1kHz and default settings in audio mode 5, unless otherwise
stated.
• Parameter setup: AT^SAIC=2,1,1,0,0,0 for MICP1 to MICN1 and AT^SAIC=2,2,2,0,0,0 for MICP2 to MICN2,
inBbcGain=0, inCalibrate=32767, outBbcGain=0, OutCalibrate=16384, sideTone=0
Frequency Response
4
0Hz - 100Hz
200Hz
300Hz - 3350Hz
3400Hz
4000Hz
≥4400Hz
-0.2
-1.1
-0.7
-39
-34
0.1
-75
dB
1.
Full scale of EPP2/EPN2 is lower than full scale of EPP1/EPN1 but the default gain is the same. 3.14dBm0
will lead to clipping if the default gain is used.
2.
The idle channel noise was measured with digital zero signal fed to decoder. This can be realized by set-
ting outCalibrate and sideTone to 0 during a call.
3.
The test signal is a 1 kHz, 0 dbm0 sine wave.
4.
This is the frequency response from a highpass and lowpass filter combination in the DAC of the baseband
chip set. If the PCM interface is used, this filter is not involved in the audio path. Audio mode 1 to 4 incor-
porate additional frequency response correction filters in the digital signal processing unit and are adjusted
to their dedicated audio devices (see Table 31).
Table 33: Voiceband transmit path
Parameter Min Typ Max Unit Test condition / Remark
Full scale input voltage (peak to
peak) for 3.14dBm0
MICP1 to MICN1 or AGND, MICP2
to MICN2 or AGND
1.6 V MICPx must be biased with
1.25V (VMIC/2)
Nominal input voltage (peak to
peak) for 0dBm0
MICP1 to MICN1 or AGND, MICP2
to MICN2 or AGND
1.1 V MICPx must be biased with
1.25V (VMIC/2)
Input amplifier gain in 6dB steps
(inBbcGain)
0 42 dB Set with AT^SNFI
Fine scaling by DSP (inCalibrate) -
∞ 0 dB Set with AT^SNFI
Microphone supply voltage VMIC 2.4 2.5 2.6 V
VMIC current 2 mA
Idle channel noise -83 -76 dBm0p
Signal to noise and distortion 70 77 dB
Table 32: Voiceband receive path
Parameter Min Typ Max Unit Test condition / remark