AK4490EN Datasheet, PDF (44/68 Pages) Asahi Kasei Microsystems – Premium 32-Bit 2ch DAC

[AK4490EN]
■ Soft Mute Operation (PCM, DSD)
The soft mute operation is performed at digital domain. When the SMUTE pin goes to “H” or the SMUTE
bit set to “1”, the output signal is attenuated by  during ATT_DATA  ATT transition time from the
current ATT level. When the SMUTE pin is returned to “L” or the SMUTE bit is returned to “0”, the mute is
cancelled and the output attenuation gradually changes to the ATT level during ATT_DATA  ATT
transition time. 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. The soft mute is effective for
changing the signal source without stopping the signal transmission.
SMUTE pin or
SMUTE bit
(1)
ATT_Level
Attenuation
(1)
(3)
-
GD
GD
(2)
(2)
AOUT
DZF pin
(4)
8192/fs
Note 30.
(1) ATT_DATA  ATT transition time. For example, this time is 7395LRCK cycles at ATT_DATA=255 in
Normal Speed Mode.
(2) The analog output corresponding to the digital input has group delay (GD).
(3) 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.
(4) When the input data for each channel is continuously zeros for 8192 LRCK cycles, the DZF pin for
each channel goes to “H”. The DZF pin immediately returns to “L” if input data are not zero.
Figure 22. Soft Mute Function
■ System Reset
The AK4490EN should be reset once by bringing the PDN pin = “L” upon power-up. It initializes register
settings of the device. The analog block of the AK4490EN exits power-down mode by MCLK input, and
the digital block exits power-down mode after the internal counter counts MCLK for 4/fs.
015013666-E-01
- 44 -
2015/12