WM8768 Datasheet, PDF (28/38 Pages) Wolfson Microelectronics plc – 24-bit, 192kHz 8-Channel DAC

WM8768
Production Data
INFINITE ZERO DETECT
When it is set, the IZD register causes an analogue mute of the DAC channel output amplifier both
when there are 1024 zeros on that channel’s DIN pin or when it is manually muted by DMUTE or
MUTEALL.
REGISTER ADDRESS BIT
0000010
4
DAC Channel Control
LABEL
IZD
DEFAULT
0
DESCRIPTION
IZD Enable
0 : Disable infinite zero mute
1: Enable infinite zero mute
This operation is only available in software mode and can sometimes create a very small click at the
output of the device.
DE-EMPHASIS MODE
Each stereo DAC channel has an individual de-emphasis control bit:
REGISTER ADDRESS BIT
0001001
[8:6]
DAC De-emphahsis
Control
0001111
4
DAC4 Control
LABEL
DEEMPH
[2:0]
DEEMPH4
DEFAULT
000
DESCRIPTION
DAC 3, 2 and 1 De-emphasis
channel selection select:
0
DAC 4 De-emphasis channel
selection select:
{DEEMPH4,DEEMPH
[2:0]}
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
DAC
CHANNEL 4
Not-DEEMPH
Not-DEEMPH
Not-DEEMPH
Not-DEEMPH
Not-DEEMPH
Not-DEEMPH
Not-DEEMPH
Not-DEEMPH
DEEMPH
DEEMPH
DEEMPH
DEEMPH
DEEMPH
DEEMPH
DEEMPH
DEEMPH
Table 14 De-emphasis Control
DAC
CHANNEL 3
Not-DEEMPH
Not-DEEMPH
Not-DEEMPH
Not-DEEMPH
DEEMPH
DEEMPH
DEEMPH
DEEMPH
Not-DEEMPH
Not-DEEMPH
Not-DEEMPH
Not-DEEMPH
DEEMPH
DEEMPH
DEEMPH
DEEMPH
DAC
CHANNEL 2
Not-DEEMPH
Not-DEEMPH
DEEMPH
DEEMPH
Not-DEEMPH
Not-DEEMPH
DEEMPH
DEEMPH
Not-DEEMPH
Not-DEEMPH
DEEMPH
DEEMPH
Not-DEEMPH
Not-DEEMPH
DEEMPH
DEEMPH
DAC
CHANNEL 1
Not-DEEMPH
DEEMPH
Not-DEEMPH
DEEMPH
Not-DEEMPH
DEEMPH
Not-DEEMPH
DEEMPH
Not-DEEMPH
DEEMPH
Not-DEEMPH
DEEMPH
Not-DEEMPH
DEEMPH
DEEMPH
DEEMPH
Refer to Figure 25, Figure 26, Figure 27, Figure 28, Figure 29 and Figure 30 for details of the De-
Emphasis performance at different sample rates.
REGISTER ADDRESS BIT
0000010
1
DAC DEEMPH
LABEL
DEEMP
ALL
DEFAULT
0
DESCRIPTION
DEEMPH Select:
0 : Normal Operation
1: De-emphasis all channels
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PD Rev 4.3 July 2010
28