AK4358_06 Datasheet, PDF (20/36 Pages) Asahi Kasei Microsystems – 192kHz 24-Bit 8ch DAC with DSD Input

ASAHI KASEI
[AK4358]
„ De-emphasis Filter
A digital de-emphasis filter is available for 32, 44.1 or 48kHz sampling rates (tc = 50/15µs) and is enabled or disabled
with DEM0 and DEM1. In case of double speed and quad speed mode, the digital de-emphasis filter is always off. When
DSD mode, DEM0-1 is invalid.
DEM1
0
0
1
1
DEM0
0
1
0
1
Mode
44.1kHz
OFF
48kHz
32kHz
Default
Table 13. De-emphasis Filter Control (Normal Speed Mode)
„ Output Volume
The AK4358 includes channel independent digital output volumes (ATT) with 128 levels at 0.5dB steps including
SMUTE. These volumes are in front of the DAC and can attenuate the input data from 0dB to –63dB and mute.
Transition time is set by AST1-0 bits(Table 15) When changing levels, transitions are executed via soft changes; thus no
switching noise occurs during these transitions. When ATTE bit is set to “0”, the DAC input data goes to “0”
immediately. It takes a time of group delay to mute the analog output. ATTE bit should be “1” to enable the volume
setting.
ATTE
1
0
ATT6-0
7FH
7EH
7DH
:
02H
01H
00H
Don’t care
Attenuation Level
0dB
-0.5dB
-1.0dB
:
-62.5dB
-63.0dB
SMUTE (-∞)
OFF ( “0” )
Default
Table 14. Attenuation Level of Output Volume
Mode
0
1
2
3
ATS1
0
0
1
1
ATS0
0
1
0
1
ATT speed
1792/fs
896/fs
256/fs
N/A
Table 15. Transition time of output volume
Default
In case of Mode 0, it takes 1792/fs to transit from 7FH(0dB) to 00H(SMUTE). In case Mode1, it takes 896/fs to transit
from 7FH(0dB) to 00H(SMUTE). In case Mode2 and 3,it takes 256/fs to transit from 7FH(0dB) to 00H (SMUTE). If PDN
pin goes to “L”, ATT6-0 registers are initialized to 7FH.ATT6-0 registers go to 7FH when RSTN bit is set to “0”. When
RSTN bit returns to “1”, ATT6-0 registers go to the set value. Digital output volume function is independent of soft mute
function.
The setting value of the register is held when switching between PCM mode and DSD mode.
MS0203-E-01
- 20 -
2006/02