AK4355 Datasheet, PDF (14/24 Pages) Asahi Kasei Microsystems – 192kHz 24-Bit 6ch DAC for DVD-Audio

ASAHI KASEI
[AK4355]
n Zero Detection
When the input data atall channel is continuously zero s for 8192 LRCK cycles, DZF pin goes to “H”. DZF pin immediately
goes to “ L” if input data of each channel is not zero after going DZF “H”. If RSTN bit is “0”, DZF pin goes to “H”. DZF pin
goes to “ L” at 4~5LRCK if input data of each channel is not zero after RSTN bit returns to “ 1”. Zero detect function can be
disabled by DZFE bit. In this case, DZF pins of both channels are always “L”. DZFB bit can invert the polarity of DZF pin.
When one of PW1-3 bit is set to“0”, the input data of DAC which the PW bit is set to ”0” should be zero in order to enable
zero detection of the other channels . When all PW1-3 bits are set to “0”, DZF pin fixes “L”.
n Soft Mute Operation
Soft mute operation is performed at digital domain. When the SMUTE bit goes to“1”, the output sig nal is attenuated by -∞
during 1024 LRCK cycles. When the SMUTE bit is returned to “1”, the mute is cancelled and the output attenuation
gradually changes to 0dB during 1024 LRCK cycles. If the soft mute is cancelled within 1024 LRCK cycles 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.
SMUTE pin
0dB
Attenuation
1024/fs
(1)
1024/fs
(3)
-∞
GD
GD
(2)
AOUT
DZF pin
(4)
8192/fs
Notes:
(1) The output signal is attenuated by -∞ during 1024 LRCK cycles (1024/fs).
(2) The analog output corresponding to the digital input has a group delay, GD.
(3) If the soft mute is cancelled within 1024 LRCK cycles, the attenuation is discontinued and returned to 0dB.
(4) When the input data at each channel is continuously zeros for 8192 LRCK cycles, DZF pin of each channel goes to
“H”. DZF pin immediately goes to “L” if input data are not zero after going DZF “H”.
Figure 5. Soft Mute and Zero Detection
MS0063-E-01
- 14 -
2002/07