AK4642EN Datasheet, PDF (41/83 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP/SPK-AMP

ASAHI KASEI
[AK4642EN]
„ De-emphasis Filter
The AK4642 includes the digital de-emphasis filter (tc = 50/15µs) by IIR filter. Setting the DEM1-0 bits enables the
de-emphasis filter (Table 29).
DEM1
0
0
1
1
DEM0
Mode
0
44.1kHz
1
OFF
0
48kHz
1
32kHz
Table 29. De-emphasis Control
Default
„ Bass Boost Function
The BST1-0 bits control the amount of low frequency boost applied to the DAC output signal (Table 30). If the BST1-0
bits are set to “01” (MIN Level), use a 47µF capacitor for AC-coupling. If the boosted signal exceeds full scale, the analog
output clips to the full scale. Figure 26 shows the boost frequency response at –20dB signal input.
Boost Filter (fs=44.1kHz)
20
MAX
15
MID
10
MIN
5
0
-5
10
100
1000
Frequency [Hz]
Figure 26. Bass Boost Frequency Response (fs=44.1kHz)
BST1
0
0
1
1
BST0
Mode
0
OFF
1
MIN
0
MID
1
MAX
Table 30. Bass Boost Control
Default
10000
MS0420-E-00
- 41 -
2005/09