AK4673 Datasheet, PDF (52/107 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP-AMP and Touch Screen Controller

[AK4673]
■ De-emphasis Filter
The AK4673 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 37 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 37. 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
MS0670-E-00
- 52 -
2007/09