AK4618 Datasheet, PDF (25/60 Pages) Asahi Kasei Microsystems – 192kHz 24-bit 6ch/12ch Audio CODEC with Microphone Interface

[AK4618]
■ De-emphasis Filter
The AK4618 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
0
1
2
3
Sampling Speed Mode
Normal Speed Mode
Normal Speed Mode
Normal Speed Mode
Normal Speed Mode
DEM11
(DEM61-21)
0
0
1
1
DEM10
(DEM60-20)
0
1
0
1
DEM
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 3.7Hz at fs=48kHz
and scales with the sampling rate (fs).
■ Master Mode and Slave Mode
Master Mode and Slave Mode are selected by setting the MS bit.
LRCK and BICK pins are outputs in Master Mode (MS bit= “1”)
LRCK and BICK pins are inputs in Slave Mode (MS bit= “0”)
The BICK and LRCK pins are in Hi-z state before an internal power up and MS bit = "1".
When a problem is occurred by this, pulldown BICK and LRCK pins by external resistance(ex. 100kohm).
PDN
L
H
MS bit
0
1
0
1
LRCK pin
Input
Hi-z
Input
Output
BICK pin
Input
Hi-z
Input
Output
Table 9. LRCK and BICK pins
015000617-E-00
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2015/01