[AK4614]
■ De-emphasis Filter
The AK4614 has a digital de-emphasis filter (tc=50/15µs) by an IIR filter. The de-emphasis filter supports only Normal
Speed Mode. This filter corresponds to three sampling frequencies (32kHz, 44.1kHz, 48kHz). De-emphasis of each DAC
can be set individually by registers, DAC1(SDTI1), DAC2(SDTI2), DAC3(SDTI3), DAC4(SDTI4), DAC5(SDTI5),
DAC6(SDTI6).
Mode
Sampling Speed Mode
DEM11
DEM10
DEM
(DEM61-21)
(DEM60-20)
0
1
2
3
Normal Speed Mode
Normal Speed Mode
Normal Speed Mode
Normal Speed Mode
0
0
1
1
0
1
0
1
44.1kHz
OFF
48kHz
32kHz
(default)
Table 8. De-emphasis control
■ Digital High Pass Filter
The ADC has a digital high pass filter for DC offset cancellation. The cut-off frequency of the HPF is 1.0Hz at fs=48kHz
and scales with the sampling rate (fs).
■ Master Clock Output
The AK4614 has a master clock output pin. If DIV bit = “1”, the MCKO pin output the frequency divided in half.
DIV
0
1
MCKO
XTI x1
XTI x1/2
(default)
Table 9. The select of Master clock output frequency
■ Master Mode and Slave Mode
Master Mode and Slave Mode are selected by setting the M/S pin. (Master Mode= “H”, Slave Mode= “L”)
LRCK and BICK pins are outputs in Master Mode (M/S pin= “H”)
LRCK and BICK pins are inputs in Slave Mode (M/S pin= “L”)
PDN
L
M/S pin
LRCK pin
Input
“L” Output
Input
BICK pin
Input
“L” Output
Input
L
H
L
H
H
Output
Output
Table 10. LRCK and BICK pins
MS1025-E-00
2008/10
- 31 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
