AK4538 Datasheet, PDF (18/70 Pages) Asahi Kasei Microsystems – 16Bit DS CODEC with MIC/HP/SPK-AMP

ASAHI KASEI
[AK4538]
OPERATION OVERVIEW
n Master Clock Source
The AK4538 requires a master clock (MCLK). This master clock is input to the AK4538 by connecting a X’tal oscillator
to XTI and XTO pins or by inputting an external CMOS-level clock to the XTI pin or by inputting an external clock that is
greater than 50% of the DVDD level to the XTI pin through a capacitor.
When using a X’tal oscillator, there should be capacitors between XTI/XTO pins and DVSS. When using an external
clock, there are two choices: direct, where an external clock is input directly to the XTI pin and indirect, where the external
clock is input through a capacitor.
Master Clock
Status
PMXTL bit
X’tal Oscillator
(Figure 13)
Oscillator ON
1
Oscillator OFF
0
External Clock Direct Input (Figure 14) Clock is input to MCKI pin.
0
MCKI pin is fixed to “L”.
0
MCKI pin is fixed to “H”.
0
MCKI pin is Hi-Z
0
AC Coupling Input
(Figure 15) Clock is input to MCKI pin.
1
Clock isn’t input to MCKI pin.
0
Table 1. Master Clock Status by PMXTL bit and MCKPD bit
MCKPD bit
0
1
0
0/1
0
1
0
1
(1) X’tal Oscillator
XTI
C
C
MCKIPD= "0"
25kΩ
PMXTL = "1"
XTO
AK4538
Figure 13. X’tal mode
- Note: The capacitor values depend on the X’tal oscillator used. (C : typ. 10 ∼ 30pF)
MS0198-E-01
- 18 -
2003/5