AK4121A_10 Datasheet, PDF (11/20 Pages) Asahi Kasei Microsystems – Asynchronous Sample Rate Converter

[AK4121A]
■ Soft Mute Operation
When the SMUTE pin changes to “H”, the output signal is attenuated from 0dB to −∞dB during 1024 OLRCK cycles.
When the SMUTE pin returns to “L”, the attenuation is cancelled and the output signal gradually changes to 0dB during
1024 OLRCK cycles. If the soft mute is cancelled before attenuating to −∞, the attenuation is discontinued and returns
to 0dB by the same cycles. The soft mute is effective for changing the signal source.
SMUTE
0dB
Attenuation Level
at SDTO
-∞dB
(1)
(2)
(1)
Notes:
(1) Transition time. 1024 OLRCK cycles (1024/fso).
(2) If the soft mute is cancelled before attenuating to −∞ after starting the operation, the attenuation is discontinued
and returned to 0dB by the same number of clock cycles.
Figure 8. Soft Mute
■ De-emphasis Filter
A digital de-emphasis filter is available for 32, 44.1 or 48kHz sampling rates (tc=50/15µs) and is enabled or disabled
with DEM0 and DEM1.
Mode
0
1
2
3
DEM1
L
L
H
H
DEM0
L
H
L
H
De-emphasis filter
44.1kHz
OFF
48kHz
32kHz
Table 4. De-emphasis Filter Control
MS0337-E-06
- 11 -
2010/04