AK4685 AKM [Asahi Kasei Microsystems], AK4685 Datasheet - Page 21

• Manufacturer Part Number: AK4685
• Description: Multi-channel CODEC with Differential Analog I/O
• Manufacturer: AKM [Asahi Kasei Microsystems]

2. Auto Setting Mode (ACKS1/2 bit = “1”)
When the ACKS1(ACKS2) bit = “1”, the DAC is in Auto Setting Mode and the sampling speed is selected automatically
by the ratio of MCLKA/LRCKA or MCLKC/LRCKC, as shown in the
DFS21-20 bit or FS11-10 bit are ignored.
■
The AK4685 includes a digital de-emphasis filter (tc=50/15μs) by IIR filter. This filter corresponds to three sampling
frequencies (32kHz, 44.1kHz, 48kHz). De-emphasis filter is off in Double speed mode and Quad speed mode. De-
emphasis of each DAC can be set individually by register.
MS1106-E-00
De-emphasis Filter
LRCKA/C
176.4kHz
192.0kHz
32.0kHz
44.1kHz
48.0kHz
88.2kHz
96.0kHz
fs
Mode
0
1
2
3
(Note: ADC is always in Normal Speed Mode)
22.5792
24.5760
128fs
Table 8. DAC Sampling Speed (ACKS bit = “1”, Auto Setting Mode)
-
-
-
-
-
Sampling Speed
Normal Speed
Normal Speed
Normal Speed
Normal Speed
512fs, 768fs
256fs, 384fs
128fs, 192fs
MCLKA/C
Table 9. DAC System Clock Example (Auto Setting Mode)
33.8688
36.8640
192fs
-
-
-
-
-
Table 10. De-emphasis control
DEM21/DEM11
22.5792
24.5760
256fs
MCLKA/C (MHz)
Normal Speed Mode
Double Speed Mode
Quad Speed Mode
-
-
-
-
-
DAC1/2 Sampling Speed (fs) LRCKA/C
0
0
1
1
- 21 -
33.8688
36.8640
384fs
-
-
-
-
-
DEM20/DEM10
Table 8
0
1
0
1
16.3840
22.5792
24.5760
512fs
120kHz~192kHz
-
-
-
-
32kHz~48kHz
64kHz~96kHz
and
Table
44.1kHz
48kHz
32kHz
24.5760
33.8688
36.8640
DEM
OFF
768fs
9. In this mode, the settings of
-
-
-
-
(default)
Sampling
Normal
Double
Speed
Quad
[AK4685]
2009/08