AK4650 Datasheet, PDF (34/86 Pages) Asahi Kasei Microsystems – 16Bit ΔΣ CODEC with MIC/HP/SPK-AMP & TSC

[AK4650]
■ 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 TM1-0 bits (Table 27). When the SMUTE bit is returned to “0”, the mute is
cancelled and the output attenuation gradually changes to 0dB during the cycle set of the TM1-0 bits. If the soft mute is
cancelled within the cycle set by the TM1-0 bits after starting the operation, the attenuation is discontinued and returned
to 0dB. The soft mute is effective for changing the signal source without stopping the signal transmission (Figure 21).
The soft mute function is independent of output volume and cascade connected between both functions.
SMUTE bit
0dB
A tte n u a tio n
TM1-0 bit
(1)
TM1-0 bit
(3)
-∞
Analog O utput
GD
GD
(2)
Figure 21. Soft Mute Function
Note:
(1) The output signal is attenuated until -∞ (“0”) by the cycle set by the TM1-0 bits.
(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 TM1-0 bits, the attenuation is discounted and returned to
0dB(the set value).
TM1
TM0
Cycle
0
0
1024/fs (default)
0
1
512/fs
1
0
256/fs
1
1
128/fs
Table 27. Soft Mute Time Setting
MS0502-E-01
- 34 -
2007/04