WM8940CGEFLSLASHV datasheet(33/88 Pages) CIRRUS

33 / 88 page

WM8940

Rev 4.4

Input

Signal

ALCSEL

PGA

Gain

ALCLVL

ATKLIM

DCYLIM

Output

of PGA

step

Figure 13 ALC Limiter Mode Operation

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

NORMAL MODE

ALCMODE = 0 (Normal Mode)

ALCATK

tATK

tATK6dB

tATK90%

0000

104µs

832µs

6ms

0001

208µs

1.66ms

12ms

0010

416µs

3.33ms

24ms

0011

832µs

6.66ms

48ms

0100

1.66ms

13.3ms

96ms

0101

3.33ms

26.6ms

192ms

0110

6.66ms

53.2ms

384ms

0111

13.3ms

106ms

767ms

1000

26.6ms

213.2ms

1.53s

1001

53.2ms

426ms

3.07s

1010

106ms

852ms

6.13s

Attack Time (s)

WM8940CGEFL/V Datasheet(PDF) 33 Page - Cirrus Logic

WM8940CGEFL/V Datasheet(HTML) 33 Page - Cirrus Logic

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88

Datasheet Download

Link URL