AK4695 Datasheet, PDF (45/107 Pages) Asahi Kasei Microsystems – 24bit 4ch CODEC with MIC/HP/SPK/LINE-AMP

[AK4695]
■ Soft Mute
Soft mute operation is performed in the digital domain. When the SMUTE bit is set “1”, the output signal is attenuated to
-∞ (“0”) after attenuated to -59.5dB, during the cycle set by SMTM bit. When the SMUTE bit is returned to “0”, the mute
status (-∞dB) is cancelled and the output attenuation level gradually changes to 0dB from -59dB during the cycle set by
SMTM bit. If the soft mute is cancelled within the cycle set by SMTM bit after starting the operation, the attenuation is
discontinued and the attenuation level returns to 0dB.
The mute status (-∞dB) is held by setting PMDSP bit = “1” and PMPFILx bit = “1” after setting SMUTE bit = “1” while
PMDSP bit = “0” and PMPFIL3-0 bits = “0”, unless changing SMUTE bit to “0”. In case of changing the SMUTE bit
setting within 2/fs after setting PMPFIL bit to “1” while PMDSP bit = “1”, the programmable filter block is powered up in
mute status if SMUTE bit = “1”, and it is powered up in IVOL setting value if SMUTE bit = “0”.
PMPFILx bit should not be changed during soft mute transition.
SMTM bit
ATT Level Transition Time from 0dB to 
Setting
fs=8kHz
fs=48kHz
0
240/fs
30ms
5ms
1
480/fs
60ms
10ms
Table 32. Output Digital Volume Transition Time Setting
(default)
SMUTE bit
0dB
Attenuation Level
SMTM
bit
(1)
SMTM
bit
(1)
(2)
-59.5dB
-
Figure 32. Soft Mute Function
(1) The input signal is attenuated by  (“0”) during the cycle set by SMTM bit.
(2) If soft mute is cancelled within the cycle set by SMTM bit after starting the operation, the attenuation is discounted and
the attenuation level returns to 0dB within the same cycle.
MS1463-E-01
- 45 -
2014/12