WM8983GEFL/V Wolfson Microelectronics, WM8983GEFL/V Datasheet - Page 48

• Manufacturer Part Number: WM8983GEFL/V
• Description: Audio CODECs Mbl Multimedia CODEC w/ 1W Speaker Driver
• Manufacturer: Wolfson Microelectronics

Specifications of WM8983GEFL/V

• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-32
• Minimum Operating Temperature: - 25 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

WM8983
w
ATTACK AND DECAY TIMES
NORMAL MODE
Table 20 ALC Normal Mode (Attack and Decay times)
Note: R32, R33, R45 and R46 register settings above need to be changed to reflect settings required
in the target application.
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).
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
10. R34 = 0x01–0 - Enable Limiter mode (ALCMODE = 1).
11. Insert 1ms delay to allow input PGA gain update by the limiter circuit.
12. R59 = 0x00–0 - Turn off ALC test mode.
13. –2 - Enable input PGA (INPPGAENL/R = 1).
t
t
ATK
DCY
13.32ms
26.64ms
53.28ms
106.6ms
13.12ms
26.24ms
1.66ms
3.33ms
6.66ms
1.64ms
3.28ms
6.56ms
52.5ms
105ms
210ms
420ms
104μs
208μs
416μs
832μs
410μs
820μs
t
t
ATK6dB
DCY6dB
Attack Time (s)
Decay Time (s)
13.32ms
26.64ms
53.28ms
106.6ms
213.2ms
426.4ms
852.8ms
1.66ms
3.33ms
6.66ms
13.1ms
26.2ms
52.5ms
105ms
210ms
420ms
840ms
832μs
3.3ms
6.6ms
1.68s
3.36s
t
t
ATK90%
DCY90%
192ms
384ms
768ms
192ms
384ms
768ms
12.28s
24.57s
96ms
12ms
24ms
48ms
96ms
1.53s
3.07s
6.14s
24ms
48ms
1.53s
3.07s
6.14s
6ms
PD, Rev 4.3, May 2010
Production Data
48