WM8980CGEFL/RV WOLFSON [Wolfson Microelectronics plc], WM8980CGEFL/RV Datasheet - Page 39

• Manufacturer Part Number: WM8980CGEFL/RV
• Description: Stereo CODEC with Speaker Driver and Video Buffer
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

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ATTACK AND DECAY TIMES
Table 19 ALC Normal Mode (Attack and Decay times)
The attack and decay times set the update times for the PGA gain. The attack time is the time
constant used when the gain is reducing. The decay time is the time constant used when the gain is
increasing. In limiter mode, the time constants are faster than in ALC mode. The time constants are
shown below in terms of a single gain step, a change of 6dB and a change of 90% of the PGAs gain
range.
Note that, these times will vary slightly depending on the sample rate used (specified by the SR
register).
NORMAL MODE
ALCMODE = 0 (Normal Mode)
ALCATK
ALCMODE = 0 (Normal Mode)
ALCDCY
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
t
t
ATK
DCY
1.66ms
3.33ms
6.66ms
13.3ms
26.6ms
53.2ms
1.64ms
3.28ms
6.56ms
13.1ms
26.2ms
52.5ms
106ms
105ms
210ms
420ms
104µs
208µs
416µs
832µs
410µs
820µs
t
t
ATK6dB
DCY6dB
Attack Time (s)
Decay Time (s)
213.2ms
1.66ms
3.33ms
6.66ms
13.3ms
26.6ms
53.2ms
3.28ms
6.56ms
13.1ms
26.2ms
52.5ms
106ms
426ms
852ms
105ms
210ms
420ms
840ms
832µs
1.68s
3.36s
t
t
ATK90%
DCY90%
23.6ms
47.2ms
94.5ms
192ms
384ms
767ms
189ms
378ms
756ms
12ms
24ms
48ms
96ms
1.53s
3.07s
6.13s
1.51s
3.02s
6.05s
12.1s
24.2s
6ms
PP, Rev 3.8, May 2012
WM8980
39