AK7600 Datasheet, PDF (14/38 Pages) Asahi Kasei Microsystems – 2/6-Channel Audio CODEC with Digital EQ

[AK7600]
■ Zero Detect Function
The AK7600 has independent zeros detect function for each DAC, which is always enabled. DZDD1-3 bits of CONT1
can select detection channel group and this function covers 6-channel outputs. Counting on “AND” for zero detected flags
of selected channels, when the input data is continuously zeros for 8192 LRCK cycles, the DZF pin goes to “H” at DZLH
bit (CONT1) is “0”, the DZF pin goes to “L” at DZLH bit (CONT1) is “1”. The DZF pin immediately returns to “L”
(DZLH bit “0”) or “H” (DZLH bit “1”) if the input data is not zero after the zero detection.
■ Soft Mute
Soft mute operation is performed in the digital domain. When the SMUTE bit is set “1”, the output signal is attenuated to
-∞ in 1024 LRCK cycles. When the SMUTE bit is returned to “0”, the mute is cancelled and the output attenuation
gradually changes to 0dB in 1024 LRCK cycles. If the soft mute is cancelled within the 1024 LRCK cycles after starting
this operation, the attenuation is discontinued and it is returned to 0dB by the same cycle. Soft mute is effective for
changing the signal source without stopping the signal transmission.
SMUTE bit
DAC Full Level
(1)
Attenuation
(2)
(4)
-∞
GD
GD
(3)
AOUT
(5)
DZF
8192/fs
Note:
(1) The transition time to attenuate input data to -∞ is 1024 LRCK cycles (1024/fs).
(2) The transition time to return to the full scale of the DAC input is 1024 LRCK cycles (1024/fs).
(3) Analog output corresponding to digital input has group delay (GD).
(4) 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.
(5) When the input data for both channels are continuously zero for 8192 LRCK cycles, the DZF pin goes to “H”. if the
DZLH bit is “0” (the DZF pin goes to “L” if the DZLH bit is “1”). The DZF pin immediately returns to “L” if the
input data are not zero after going to DZF “H” (DZLH bit =“0”).
Figure 11 Soft Mute and Zero Detect Function
MS0999-E-00
- 14 -
2008/09