TFA9812_2
© NXP B.V. 2009. All rights reserved.
Preliminary data sheet
Rev. 02 — 22 January 2009
20 of 66
NXP Semiconductors
TFA9812
BTL stereo Class-D audio amplifier with I
2
S input
8.5.2 Digital volume control
In I
2
C control mode both audio channels have separate digital volume control. In Legacy
control mode the volume control of both channels is common and the volume control
setting depends on the supply voltage on the pin AVOL (32).
8-bit volume control is available per channel. This is dB-linear down to
−
124 dB in steps of
0.5 dB. The last step of the volume control is mute.
shows the various settings and their related channel suppression:
Fig 7.
Transfer functions for several center frequencies f
c
Fig 8.
Transfer functions for several gain factors G
010aaa223
Frequency (Hz)
10
1
10
5
10
4
10
2
10
3
4
8
12
Gain
(dB)
0
010aaa224
Frequency (Hz)
10
1
10
5
10
4
10
2
10
3
0
-6
6
12
Gain
(dB)
-12
