CS4244-CNZ Cirrus Logic Inc, CS4244-CNZ Datasheet - Page 41

• Manufacturer Part Number: CS4244-CNZ
• Description: IC 4 Input / 5 Output CODEC
• Manufacturer: Cirrus Logic Inc

DS900PP2
lower values will permit closer tracking of the envelope but may re-introduce zipper noise. The default val-
ues of these registers are recommended as a starting point. It is possible to disable the volume envelope
tracking and always produce a constant ramp rate. To accomplish this, set the
DELAY[2:0]
The envelope counter time out period which defines the boundary between the two soft-ramping behav-
iors depends on the base rate. It is equal to approximately 100,000/Fs.
The
of the base period between volume steps of
resolution of the volume control engine. Consequently the soft-ramp rate can be expressed in ms/dB as
shown in
4.6.5.3
The CS4244 is equipped with a Noise Gate feature that mutes the output if the signal drops below a given
bit depth for 8192 samples. While the enabling or disabling of the Noise Gate feature is done for the entire
DAC1-4 output path, each of the channels within the path have separate monitoring circuitry that will trig-
ger the Noise Gate function independently of the other channels. For instance, if the Noise Gate were en-
abled for and one of the channels were to exhibit a pattern of more than 8192 samples of either all “1’s”
or all “0’s”, the output for that particular channel would be muted (and subsequently unmuted), indepen-
dently of the other channels. To enable the Noise Gate feature, set the DAC1-4 NG[2:0] bits to the desired
bit depth. The available bit depth settings are shown in
Full-scale ramp is 96 dB (-90 dB to +6 dB)
Ramp Rate
128 x Base
16 x Base
32 x Base
64 x Base
1 x Base
2 x Base
4 x Base
8 x Base
MUTE
Table
Noise Gate
DELAY[1:0],
values to match the
6.
Time to Ramp
to Full Scale
Fs = 48 kHz or 96 kHz (Base = 48 kHz)
1365.33
2730.67
170.67
341.33
682.67
21.33
42.67
85.33
(ms)
MIN
DELAY[2:0], and
Time to Ramp
MUTE DELAY[1:0]
Table 6. Soft Ramp Rates
6 dB (ms)
170.67
10.67
21.33
42.67
85.33
1.33
2.67
5.33
6.02
MAX DELAY[2:0]
/
64
ms/dB
14.17
28.35
0.22
0.44
0.89
1.77
3.54
7.09
dB, which is approximately 0.1 dB. This is the internal
setting.
Table
Time to Ramp
7.
to Full Scale
Fs = 32 kHz or 64 kHz (Base = 32 kHz)
1024
2048
4096
(ms)
bits specify a delay equal to a multiple
128
256
512
32
64
Time to Ramp
6 dB (ms)
MIN DELAY[2:0]
128
256
16
32
64
2
4
8
CS4244
ms/dB
10.63
21.26
42.52
and
0.33
0.66
1.33
2.66
5.32
MAX
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