AK4497 Datasheet, PDF (64/98 Pages) Asahi Kasei Microsystems – Quality Oriented 32-Bit 2ch DAC

[AK4497]
■ Soft Mute Operation (PCM, DSD, EXDF)
The soft mute operation is performed at digital domain. When the SMUTE pin goes to “H” or the SMUTE
bit set to “1”, the output signal is attenuated by  during ATT_DATA  ATT transition time from the
current ATT level. When the SMUTE pin is returned to “L” or the SMUTE bit is returned to “0”, the mute is
cancelled and the output attenuation gradually changes to the ATT level during ATT_DATA  ATT
transition time. If the soft mute is cancelled before attenuating  after starting the operation, the
attenuation is discontinued and returned to ATT level by the same cycle. The soft mute is effective for
changing the signal source without stopping the signal transmission.
SMUTE pin or
SMUTE bit
(1)
ATT_Level
Attenuation
(1)
(3)
-
(2) GD
(2) GD
AOUTL/R
DZFL/R pin
(4)
8192/fs
Notes:
(1) ATT_DATA  ATT transition time. For example, this time is 4080LRCK cycles (1020/fs) at
ATT_DATA=255 in PCM Normal Speed Mode.
(2) The analog output corresponding to the digital input has group delay (GD).
(3) If the soft mute is cancelled before attenuating  after starting the operation, the attenuation is
discontinued and returned to ATT level by the same cycle.
(4) When the input data for each channel is continuously zeros for 8192 LRCK cycles (16384 LRCK
cycles in DSD 512fs mode), the DZF pin for each channel goes to “H”. The DZF pin immediately
returns to “L” if input data are not zero.
Figure 49. Soft Mute Function
Rev. 0.1
- 64 -
2015/11