AK4640_05 AKM [Asahi Kasei Microsystems], AK4640_05 Datasheet - Page 22

• Manufacturer Part Number: AK4640_05
• Description: 16-Bit ?? CODEC with MIC/HP/SPK-AMP
• Manufacturer: AKM [Asahi Kasei Microsystems]

ASAHI KASEI
The AK4640 requires a master clock (MCKI). This master clock is input to the AK4640 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.
(1) X’tal Oscillator
MS0273-E-02
Master Clock Source
X’tal Oscillator
External Clock Direct Input
AC Coupling Input
Note: The capacitor values depend on the X’tal oscillator used. (C: typ. 10 ∼ 30pF)
Master Clock
C
C
Table 1. Master Clock Status by PMXTL bit and MCKPD bit
XTO
XTI
(Figure 13)
(Figure 14)
(Figure 15)
OPERATION OVERVIEW
25kΩ(typ)
MCKPD = "0"
PMXTL = "1"
Figure 13. X’tal mode
Clock isn’t input to MCKI pin.
Clock is input to MCKI pin.
Clock is input to MCKI pin.
MCKI pin is fixed to “H”.
MCKI pin is fixed to “L”.
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MCKI pin is Hi-Z
Oscillator OFF
Oscillator ON
Status
AK4640
PMXTL bit
1
0
0
0
0
0
1
0
MCKPD bit
0/1
0
0
1
0
0
1
1
[AK4640]
2005/04