AK4584_01 Datasheet, PDF (21/53 Pages) Asahi Kasei Microsystems – 24Bit 96kHz Audio CODEC with DIT/DIR

ASAHI KASEI
[AK4584]
„ System Clock
The master clock (MCLK) is derived from either a X’tal oscillator or the recovered clock from the AK4584’s PLL. MCLK
frequency is set by ICKS1-0 bits (Table 5) for X’tal mode and external clock mode. The sampling speed (normal, double
or quad speed modes) is selected by DFS1-0 bits (Table 6). The ADC is powered down during quad speed mode.
When using a X’tal oscillator, external loading capacitors between XTI/XTO pins and DVSS are required. An external
clock can be input to the XTI pin with the XTO pin left floating. The input can accept both CMOS and AC coupled clock
sources with 40%DVDD.
In slave mode, the LRCK clock input must be synchronized with MCLK, however the phase is not critical. All external
clocks (MCLK, BICK and LRCK) must be present unless PDN pin = “L” or all parts are powered down by control register,
otherwise excessive current may be produced by the internal dynamic logic. In master mode, the master clock (MCLK)
must be provided by a X’tal oscillator, external clock or internal PLL unless PDN pin = “L”.
Mode
0
1
2
3
MCLK
ICKS1
ICKS0
Normal
Double
Quad
(DFS1-0 = “00”) (DFS1-0 = “01”) (DFS1-0 = “10”)
0
0
256fs
N/A
N/A
0
1
384s
N/A
N/A
1
0
512fs
256fs
128fs
1
1
768fs
384fs
192fs
Table 5. Master Clock Input Frequency Select (X’tal Mode)
Default
DFS1
0
0
1
1
DFS0
Sampling Rate
0
Normal Speed
1
Double Speed
0
Quad Speed
1
N/A
Table 6. Sampling Speed
Default
MCLK
Normal
256fs
384fs
512fs
768fs
fs=44.1kHz
11.2896MHz
16.9344MHz
22.5792MHz
33.8688MHz
MCLK
Double
128fs
192fs
256fs
384fs
fs=88.2kHz
N/A
N/A
22.5792MHz
33.8688MHz
MCLK
Quad
64fs
96fs
128fs
192fs
fs=176.4kHz
N/A
N/A
22.5792MHz
33.8688MHz
MCLK
Normal
256fs
384fs
512fs
768fs
MCLK
MCLK
fs=48kHz
Double
fs=96kHz
Quad
12.288MHz
128fs
N/A
64fs
18.432MHz
192fs
N/A
96fs
24.576MHz
256fs
24.576MHz
128fs
36.864MHz
384fs
36.864MHz
192fs
Table 7. Master Clock Frequencies example
fs=192kHz
N/A
N/A
24.576MHz
36.864MHz
* X’tal mode supports from 11.2896MHz to 24.576MHz.
* Frequencies over 24.576MHz are supported in external clock mode only.
MS0118-E-00
- 21 -
2001/11