AK4452VN Datasheet, PDF (48/91 Pages) Asahi Kasei Microsystems – 115dB 768kHz 32-bit 2ch Premium DAC

[AK4452]
■ Output Volume (PCM mode, DSD mode)
The AK4452 has a channel-independent digital attenuator (256 levels, 0.5dB steps). Attenuation level of each
DAC can be set by ATT7-0 bits (register 03-04H), respectively (Table 18). Input data is attenuated from 0dB
to -127dB including Mute. The transition between set values is a soft transition, thus no switching noise is
occurred.
ATT7-0bits
(register03-04H)
Attenuation Level
FFH
+0dB
(default)
FEH
-0.5dB
FDH
-1.0dB
:
:
:
:
02H
-126.5dB
01H
-127.0dB
00H
MUTE (-∞)
Table 18. Attenuation level of Digital Attenuator
Transition time between set values of ATL/R7-0 bits can be selected by the ATS1-0 bits (Table 19). The
transition between set values is a soft transition in Mode0/1/2/3 eliminating switching noise in the transition.
The register settings are maintained when switching the mode between PCM and DSD modes.
Mode
ATS1
ATS0 ATT speed
0
0
0
4080/fs ^(default)
1
0
1
2040/fs
2
1
0
510/fs
3
1
1
255/fs
Table 19. Transition Time between Set Values of ATT7-0 bits
The transition between set values is a soft transition of 4080 levels in mode 0. It takes 4080/fs (92.5ms
@fs=44.1kHz) from FFH to 00H. If the PDN pin goes to “L”, ATT7-0 bits are initialized to FFH.
If the digital volume is changed during reset, the volume will be changed to the setting value after releasing the
reset. If the volume is changed in 5/fs after releasing a reset, the volume is changed immediately without soft
transition.
In DSD mode, the digital volume is set to MUTE by setting ATT7-0 bits = “02H” or “01H”.
Rev. 0.1
- 48 -
2014/04