
ASAHI KASEI 
[AK4341] 
OPERATION OVERVIEW 
■
 System Clock 
The external clocks, which are required to operate the AK4341, are MCLK, LRCK and BICK. The master clock (MCLK) 
should be synchronized with LRCK but the phase is not critical. The MCLK is used to operate the digital interpolation 
filter and the delta-sigma modulator. There are two methods to set MCLK frequency. In Manual Setting Mode (ACKS pin 
= “L”, Normal Speed Mode), the frequency of MCLK is set automatically. In Auto Setting Mode (ACKS pin = “H”), 
MCLK frequency is detected automatically and then the internal master clock becomes the appropriate frequency (Table 
1). 
The AK4341 is automatically placed in the power save mode when MCLK stops in the normal operation mode (PDN pin 
= “H”), and the analog output becomes the VCOM voltage. After MCLK is input again, the AK4341 is powered up. After 
exiting reset at power-up etc., the AK4341 is in the power-down mode until MCLK and LRCK are input. 
ACKS pin 
LRCK 
fs 
128fs 
192fs 
256fs 
H 
32.0kHz 
- 
- 
- 
44.1kHz 
- 
- 
- 
48.0kHz 
- 
- 
- 
88.2kHz 
- 
- 
22.5792
96.0kHz 
- 
- 
24.5760
176.4kHz 
22.5792 
33.8688 
- 
192.0kHz 
24.5760 
36.8640 
- 
L 
32.0kHz 
- 
- 
8.1920 
44.1kHz 
- 
- 
11.2896 
48.0kHz 
- 
- 
12.2880 
MCLK (MHz) 
384fs 
- 
- 
- 
33.8688 
36.8640 
- 
- 
12.2880 
16.9344 
18.4320 
512fs 
16.3840 
22.5792 
24.5760 
- 
- 
- 
- 
16.3840 
22.5792 
24.5760 
768fs 
24.5760 
33.8688 
36.8640 
- 
- 
- 
- 
24.5760 
33.8688 
36.8640 
1152fs 
36.8640
- 
- 
- 
- 
- 
- 
36.8640
- 
- 
Sampling
Speed 
Normal 
Double 
Quad 
Normal 
Table 1. ACKS pin setting and system clock example 
■
 Audio Serial Interface Format 
The Audio data is shifted in via the SDTI pin using BICK and LRCK inputs. The DIF pin can selects two serial data 
modes as shown in Table 2. In all modes the serial data is MSB-first, 2’s compliment format and latched on the rising edge 
of BICK. 
Mode 
DIF 
SDTI Format 
0 
L 
24bit MSB justified 
1 
H 
24bit I
2
S 
Table 2. Audio Data Formats 
BICK 
≥
48fs 
≥
48fs 
Figure 
Figure 1
Figure 2
MS0558-E-01 
2007/03 
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