AK4687 AKM [Asahi Kasei Microsystems], AK4687 Datasheet - Page 15

• Manufacturer Part Number: AK4687
• Description: Asynchronous Stereo CODEC with Capless Stereo Selector
• Manufacturer: AKM [Asahi Kasei Microsystems]

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External clocks (MCLK2, BICK2 and LRCK2) must always be present whenever the DAC is in normal operation (PDN
pin = “H” or PWDA2 bit= “1”). The master clock (MCLK2) must be synchronized with LRCK2 but the phase is not
critical. MCLK2 clock is used for interpolation filter and delta sigma modulator. During operation, DAC is automatically
reset and the analog output goes to 0V (typ) if MCLK2, LRCK2 and BICK2 are stopped. This reset is released, and the
DAC starts operation when MCLK2, LRCK2 and BICK2 are input again. The DAC is in power-down mode until
MCLK2, BICK2 and LRCK2 are supplied.
There are two modes for controlling the sampling speed of DAC. One is the Manual Setting Mode (ACKS bit = “0”) using
the DFS1-0 bits, and the other is Auto Setting Mode (ACKS bit = “1”).
1. Manual Setting Mode (ACKS bit = “0”)
When the ACKS bit = “0”, DAC is in Manual Setting Mode and the sampling speed is selected by DFS1-0 bits
MS1307-E-00
PORT2 (DAC) Clock Control
Table 10. PORT2(DAC) system Clock Example (Normal Speed Mode @Manual Setting Mode)
Table 11. PORT2(DAC)system Clock Example(Double Speed Mode @Manual Setting Mode)
Table 12. PORT2(DAC) system Clock Example (Quad Speed Mode @Manual Setting Mode)
176.4kHz
192.0kHz
DFS1 bit
88.2kHz
96.0kHz
32.0kHz
44.1kHz
48.0kHz
LRCK2
LRCK2
LRCK2
Table 9. PORT2(DAC) Sampling Speed (ACKS bit = “0”, Manual Setting Mode)
Fs
Fs
Fs
0
0
1
1
DFS0 bit
0
1
0
1
11.2896
12.2880
22.5792
24.5760
11.2896
12.2880
8.1920
128fs
128fs
256fs
Normal Speed Mode
Double Speed Mode
Quad Speed Mode
Not Available
16.9344
18.4320
33.8688
36.8640
12.2880
16.9344
18.4320
192fs
192fs
384fs
DAC Sampling Speed (fs)
MCLK2 (MHz)
MCLK2 (MHz)
MCLK2 (MHz)
- 15 -
22.5792
24.5760
16.3840
22.5792
24.5760
256fs
256fs
512fs
-
-
128kHz~192kHz
32kHz~48kHz
64kHz~96kHz
-
33.8688
36.8640
24.5760
33.8688
36.8640
384fs
384fs
768fs
-
-
(default)
BICK2 (MHz)
BICK2 (MHz)
BICK2 (MHz)
11.2896
12.2880
5.6448
6.1440
2.0480
2.8224
3.0720
64fs
64fs
64fs
[AK4687]
(Table
2011/05
9).