AK4490EQ Datasheet, PDF (29/68 Pages) Asahi Kasei Microsystems – Premium 32-Bit 2ch DAC

[AK4490]
When MCLK= 256fs/384fs, auto setting mode supports sampling rate of 32kHz~96kHz (Table 7). However,
the DR and S/N performances will degrade approximately 3dB as compared to when MCLK= 512fs/768fs
when the sampling rate is 32kHz~48kHz.
ACKS pin
MCLK
DR,S/N
L
256fs/384fs/512fs/768fs
120dB
H
256fs/384fs
117dB
H
512fs/768fs
120dB
Table 7. Relationship of MCLK Frequency and DR, S/N Performance (fs = 44.1kHz)
3. Digital filter
The AK4490 has four kinds of digital filter selected by SD and SLOW pins. Different sound qualities on
playback can be selected by these filters.
SD pin
L
L
H
H
SLOW pin
Mode
L
Sharp roll-off filter
H
Slow roll-off filter
L
Short delay Sharp roll-off filter
H
Short delay Slow roll-off filter
Table 8. Digital Filter Setting
(default)
The AK4490 can be operated on a slower sampling frequency. This mode is available when the SSLOW pin =
“H”.
(2) Serial Mode (PSN pin = “L”)
1. Manual Setting Mode (ACKS bit = “0”)
MCLK frequency is detected automatically and the sampling speed is set by DFS2-0 bits (Table 9). The
MCLK frequency corresponding to each sampling speed should be provided externally (Table 10). The
AK4490 is set to Manual Setting Mode at power-up (PDN pin = “L” →“H”). When DFS2-0 bits are changed,
the AK4490 should be reset by RSTN bit.
DFS2
0
0
0
0
1
1
1
1
DFS1 DFS0
Sampling Rate (fs)
0
0
Normal Speed Mode 30kHz  54kHz (default)
0
1
Double Speed Mode 54kHz  108kHz
1
0
Quad Speed Mode
120kHz 
216kHz
1
1
Reserved
-
0
0
Oct Speed Mode
384kHz
0
1
Hex Speed Mode
768kHz
1
0
Reserved
-
1
1
Reserved
-
Table 9. Sampling Speed (Manual Setting Mode @Serial Mode)
MS1648-E-03
- 29 -
2014/11