Specifications

TC35 / TC37 Hardware Interface Description
TC35_37_HD_02_V03.10 - Released Page 83 of 92 21.12.2001
6.5.4 Voiceband transmit path
The values specified below were tested to 1kHz and 0dB gain stage, unless otherwise
stated.
Audio mode = 5 for MICP1 to MICN1 and 6 for MICP2 to MICN2, inBbcGain= 0, inCalibrate
= 32767, outBbcGain = 0, OutCalibrate = 16384, sideTone = 0
Table 37: 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
fine scaling by DSP (inCalibrate) -# 0 dB
Input impedance 2.0 k"
Microphone supply voltage ON
Ri = 4k"
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"
0 V
Microphone supply in power down
mode
see Figure 44
2.65 V
to ADC
Power down
MICP1
MICN1
1 kΩ 1 kΩ
1 kΩ 1 kΩ
10 µF
MICP2
MICN2
1 kΩ 1 kΩ
1 kΩ 1 kΩ
10 µF
Figure 44: Structure of audio inputs