WM8950 Datasheet, PDF (23/52 Pages) Wolfson Microelectronics plc – ADC WITH MICROPHONE INPUT AND PROGRAMMABLE DIGITAL FILTERS

Preliminary Technical Data
WM8950
REGISTER BIT
ADDRESS
R32
8
ALC Control 1
5:3
2:0
R33
7:4
ALC Control 2
3:0
8
LABEL
DEFAULT
DESCRIPTION
ALCSEL
0
ALC function select
0=ALC disabled
1=ALC enabled
ALCMAXGAIN 111
[2:0]
(+35.25dB)
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
ALCMINGAIN 000 (-12dB) Set minimum gain of PGA
[2:0]
000=-12dB
001=-6dB
010=0dB
011=+6dB
100=+12dB
101=+18dB
110=+24dB
111=+30dB
ALCHLD
0000
ALC hold time before gain is increased.
[3:0]
(0ms)
0000 = 0ms
0001 = 2.67ms
0010 = 5.33ms
… (time doubles with every step)
1111 = 43.691s
ALCLVL
[3:0]
1011
(-12dB)
ALC target – sets signal level at ADC
input
0000 = -28.5dB FS
0001 = -27.0dB FS
… (1.5dB steps)
1110 = -7.5dB FS
1111 = -6dB FS
ALCZC
0 (zero cross ALC uses zero cross detection circuit.
off)
w
PTD Rev 2.1 June 2005
23