AK4641 Datasheet, PDF (29/51 Pages) Asahi Kasei Microsystems – 16 BIT CODEC WITH BLUETOOTH INTERFACE

ASAHI KASEI
[AK4641]
„ Soft Mute
Soft mute operation is performed in the digital domain. When the SMUTE bit goes to “1”, the output signal is attenuated
by −∞ (“0”) during the cycle set by the TM bit. When the SMUTE bit is returned to “0”, the mute is cancelled and the
output attenuation gradually changes to the digital attenuator level of ATTL/R7-0 bits during the cycle set by the TM bit.
If the soft mute is cancelled within the cycle set by the TM bit after starting the operation, the attenuation is discontinued
and returned to the digital attenuator level. The soft mute is effective for changing the signal source without stopping the
signal transmission.
Table 15 shows the Soft Mute Time when the digital attenuator level is 0dB (ATTL/R7-0 bits = “0”). As the digital
attenuator level is less than 0dB, the Soft Mute Time becomes shorter.
TM
Cycle
0
1061/fs Default
1
256/fs
Table 15. Soft Mute Time Setting
SMUTE bit
ATTL/R7-0 bits
Attenuation
TM bit
(1)
TM bit
(3)
−∞
GD
GD
(2)
Analog Output
Figure 26. Soft Mute Function
NOTE:
(1) The output signal is attenuated until −∞ (“0”) by the cycle set by the TM bit.
(2) Analog output corresponding to digital input has the group delay (GD).
(3) If the soft mute is cancelled within the cycle of setting the TM bit, the attenuation is discounted and returned to
0dB(the set value).
MS0301-E-00
- 29 -
2004/05