MC45 Hardware Interface Description
P R E L I M I N A R Y
MC45_HD_01_V00.02a
Page 85 of 90
12.08.2002
6.5.5 Voiceband transmit path
Test conditions:
·
The values specified below were tested to 1kHz and 0dB gain stage, unless otherwise
stated.
·
Parameter setup: Audio mode = 5 for MICP1 to MICN1 and 6 for MICP2 to MICN2,
inBbcGain= 0, inCalibrate = 32767, outBbcGain = 0, OutCalibrate = 16384, sideTone = 0
Table 33: Voiceband transmit path
Parameter
Min
Typ
Max
Unit
Test condition/Remark
Input voltage (peak to peak)
MICP1 to MICN1, MICP2 to
MICN2
1.03
V
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
Input impedance MIC1
50
k
Ω
Input impedance MIC2
2.0
k
Ω
Microphone supply voltage ON
Ri = 4k
Ω
2.57
2.17
1.77
2.65
2.25
1.85
2.73
2.33
1.93
V
V
V
no supply current
@ 100µA
@ 200µA
Microphone supply voltage OFF ;
Ri = 4k
Ω
0
V
Microphone supply in POWER
DOWN mode
