TFA9812_2
© NXP B.V. 2009. All rights reserved.
Preliminary data sheet
Rev. 02 — 22 January 2009
16 of 66
NXP Semiconductors
TFA9812
BTL stereo Class-D audio amplifier with I
2
S input
In I
2
C control mode the following sample frequency f
s
can be used: 8 kHz, 11.025 kHz,
12 kHz, 16 kHz, 22.05 kHz, 24 kHz, 32 kHz, 44.1 kHz, 48 kHz, 64 kHz, 88.2 kHz, 96 kHz,
128 kHz, 176.4 kHz or 192 kHz. The I
2
C control for f
s
selection can be found in
In Legacy control mode the following sample frequencies (f
s
) can be used: 32 kHz,
44.1 kHz or 48 kHz.
8.4.2 Digital audio data format control
The BCK-to-WS and MCLK-to-WS frequency ratios are automatically detected, so no
control settings need to be configured for these.
In I
2
C control mode all the formats listed in
are supported. The appropriate I
2
C
controls for selecting the supported formats can be found in
control mode only a subset of the supported formats can be used. These are shown in
and the required pin control is given in
.
See
for details of how to enable Legacy control mode.
8.5 Digital signal-processing features
8.5.1 Equalizer
8.5.1.1
Equalizer options
The equalizer function can be bypassed and the equalizer can be configured to either a
5-band or 10-band function. These settings are for both audio channels simultaneously.
There are 20 bands in the equalizer. These are distributed as follows:
•
Bands A1 to A5 are bands 1 to 5 of output 1 (used in 5-band and 10-band
configuration).
•
Bands B1 to B5 are bands 1 to 5 of output 2 (used in 5-band and 10-band
configuration).
•
Bands C1 to C5 are bands 6 to 10 of output 1 (used in 10-band configuration only).
•
Bands D1 to D5 are bands 6 to 10 of output 2 (used in 10-band configuration only).
In I
2
C control mode each band can be configured separately using I
2
C register settings.
In Legacy control mode the equalizer is bypassed.
8.5.1.2
Equalizer band function
The shape of each parametric equalizer band is determined by the three filter parameters:
•
(Relative) center frequency
.
•
Quality factor Q.
•
Gain factor G.
Table 13.
Digital audio data format selection in Legacy control mode
SCL/SFOR pin value
Interface formats (MSB-first)
0
I
2
S
1
MSB-justified
ω
2
π
f
c
f
s
⁄
(
)
=
