WM8976 Wolfson Microelectronics Ltd., WM8976 Datasheet - Page 92

• Manufacturer Part Number: WM8976
• Description: The WM8976 is a low power, high quality stereo codec designed for portable applications such as Digital still camera or Digital Camcorde
• Manufacturer: Wolfson Microelectronics Ltd.

WM8976
w
32 (20h)
33 (21h)f
34 (22h)
REGISTER
ADDRESS
8
7:6
5:3
2:0
7:4
3:0
8
7:4
BIT
ALCSEL
ALCMAXGAIN
ALCMINGAIN
ALCHLD
ALCLVL
ALCMODE
ALCDCY
[3:0]
LABEL
00
111
000
0000
0
1011
0
0011
0011
DEFAULT
ALC function select:
0=ALC off
1=ALC on
Reserved
Set Maximum Gain of PGA
111=+35.25dB
110=+29.25dB
101=+23.25dB
100=+17.25dB
011=+11.25dB
010=+5.25dB
001=-0.75dB
000=-6.75dB
Set minimum gain of PGA
000=-12dB
001=-6dB
010=0dB
011=+6dB
100=+12dB
101=+18dB
110=+24dB
111=+30dB
ALC hold time before gain is increased.
0000 = 0ms
0001 = 2.67ms
0010 = 5.33ms
… (time doubles with every step)
1111 = 43.691s
ALC target – sets signal level at ADC input
1111 : -1.5dBFS
1110 : -1.5dBFS
1101 : -3dBFS
1100 : -4.5dBFS
...... (-1.5dB steps)
0001 : -21dBFS
0000 : -22.5dBFS
Determines the ALC mode of operation:
0=ALC mode
1=Limiter mode
Decay (gain ramp-up) time
(ALCMODE ==0)
0000
0001
0010
… (time doubles with every step)
1010 or
higher
Decay (gain ramp-up) time
(ALCMODE ==1)
0000
Per step
410us
820us
1.64ms
420ms
Per step
90.8us
DESCRIPTION
Per 6dB
3.3ms
6.6ms
13.1ms
3.36s
Per 6dB
726.4us
90% of
range
24ms
48ms
192ms
24.576s
90% of
range
5.26ms
PP Rev 3.0 April 2006
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
Input Limiter/
Automatic
Level Control
(ALC)
REFER TO
Pre-Production
92