AK4524 Datasheet, PDF (12/31 Pages) Asahi Kasei Microsystems – 24BIT 96KHZ AUDIO CODEC

ASAHI KASEI
[AK4524]
OPERATION OVERVIEW
n System Clock Input
The master clock (MCLK) can be either a crystal resonator placed across the XTI and XTO pin, or external clock input to
the XTI pin with the XTO pin left floating. The master clock frequency can be selected by CMODE and CKS0-1 (Table 1).
The sampling speed (normal speed mode, double speed mode or four times speed monitor mode) is selected by DFS0-1
(Table 2). The ADC is powered down during four times speed monitor mode. The frequency of the master clock output
(CLKO) is the same as MCLK frequency and the output can be enabled or disabled by XTALE pin. When the CLKO
output is not used externally, it should be disabled.
When using a crystal oscillator, external loading capacitors (between XTI/XTO and DGND) are required.
In slave mode, the LRCK clock input must be synchronized with MCLK, however the phase is not critical. Internal timing
is synchronized to LRCK upon power-up. All external clocks must be present unless PD =”L” or all parts are powered
down by control register, otherwise excessive current may result from abnormal operation of internal dynamic logic. In
master mode, the clocks should be supplied by critical oscillation except for power down or the external clock (MCLK)
should not be stopped.
DFS1
0
0
1
1
CMODE
0
0
0
1
1
CKS1
0
0
1
0
0
CKS0
0
1
0
0
1
MCLK
256fsn
512fsn
1024fsn
384fsn
768fsn
at reset
Table 1. Master clock frequency select
* fsn is a sampling rate at normal speed mode.
DFS0
0
1
0
1
Sampling Rate
fsn
Normal speed
fsd=2 x fsn Double speed
fsq=4 x fsn 4 times speed (SDTO=”L”)
fsq=4 x fsn 4 times speed (SDTO=”L”)
Monitor mode
-
-
Simple Decimation
2 tap filter
at reset
Table 2. Sampling speed
MCLK
256fsn
512fsn
1024fsn
384fsn
768fsn
fsn=44.1kHz
11.2896MHz
22.5792MHz
45.1584MHz
16.9344MHz
33.8688MHz
fsn=48kHz
12.288MHz
24.576MHz
49.152MHz
18.432MHz
36.864MHz
Normal
256fsn
512fsn
1024fsn
384fsn
768fsn
Double
N/A
256fsd
512fsd
N/A
384fsd
4 times
N/A
128fsq
256fsq
N/A
192fsq
Table 3. Master clock frequency
* X’tal mode operates from 11.2896MHz to 24.576MHz.
* The frequency over 24.576MHz supports only external clock mode.
M0050-E-01
- 12 -
1999/5