Datasheet

TLV320AIC1110
SLAS359 – DECEMBER 2001
25
www.ti.com
PRINCIPLES OF OPERATION
transmit operation (continued)
_
+
_
+
V
ref
510 kΩ
510 kΩ
34 kΩ
34 kΩ
C
i
MIC1N
C
i
MIC1P
M
I
C
R
mic
R
mic
MBIAS
Figure 12. Typical Microphone Interface
microphone mute function
Transmit channel muting provides 80-dB attenuation of the input microphone signal. The MICMUTE function
can be selected by setting bit 6 of the power control register through the I
2
C interface.
transmit channel gain control
The values in the transmit PGA control registers control the gain in the transmit path. The total TX channel gain
can vary from 41.5 dB to 19.5 dB. The default total TX channel gain is 23.5 dB.
Table 2. Transmit Gain Control
BIT NAME MIC AMP1 MIC AMP2 TX PGA
GAIN
MODE
TOTAL TX GAIN
TP3 TP2 TP1 TP0 GAIN GAIN GAIN MIN TYP MAX UNIT
0 0 0 0 23.5 18 0 Extended 41.3 41.5 41.7 dB
0 0 0 1 23.5 18 –2 Extended 39.3 39.5 39.7 dB
0 0 1 0 23.5 18 –4 Extended 37.3 37.5 37.7 dB
0 0 1 1 23.5 18 –6 Extended 35.3 35.5 35.7 dB
0 1 0 0 23.5 18 –8 Extended 33.3 33.5 33.7 dB
0 1 0 1 23.5 18 –10 Extended 31.3 31.5 31.7 dB
1 0 0 0 23.5 6 0 Normal 29.3 29.5 29.7 dB
1 0 0 1 23.5 6 –2 Normal 27.3 27.5 27.7 dB
1 0 1 0 23.5 6 –4 Normal 25.3 25.5 25.7 dB
1 0 1 1 23.5 6 –6 Normal 23.3 23.5 23.7 dB
1 1 0 0 23.5 6 –8 Normal 21.3 21.5 21.7 dB
1 1 0 1 23.5 6 –10 Normal 19.3 19.5 19.7 dB