AK4644 Datasheet, PDF (48/96 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP/RCV-AMP

ASAHI KASEI
[AK4644]
„ De-emphasis Filter
The AK4644 includes the digital de-emphasis filter (tc = 50/15µs) by IIR filter. Setting the DEM1-0 bits enables the
de-emphasis filter (Table 37).
DEM1
0
0
1
1
DEM0
Mode
0
44.1kHz
1
OFF
0
48kHz
1
32kHz
Table 37. 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 38). 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 38 shows the boost frequency response at –20dB signal input.
0
MAX
-5
MID
-10
MIN
-15
-20
-25
10
Boost Filter (fs=44.1kHz)
100
1000
Frequency [Hz]
Figure 38. Bass Boost Frequency Response (fs=44.1kHz)
BST1
0
0
1
1
BST0
Mode
0
OFF
1
MIN
0
MID
1
MAX
Table 38. Bass Boost Control
Default
10000
MS0477-E-01
- 48 -
2006/10