ak4645 ETC-unknow, ak4645 Datasheet - Page 49

• Manufacturer Part Number: ak4645
• Description: Stereo Codec With Mic/hp-amp
• Manufacturer: ETC-unknow

ASAHI KASEI
The AK4645 includes the digital de-emphasis filter (tc = 50/15µs) by IIR filter. Setting the DEM1-0 bits enables the
de-emphasis filter (Table 37).
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.
MS0543-E-00
De-emphasis Filter
Bass Boost Function
-10
-15
-20
-25
-5
0
10
MAX
MID
MIN
Figure 38. Bass Boost Frequency Response (fs=44.1kHz)
DEM1
BST1
0
0
1
1
0
0
1
1
Table 37. De-emphasis Control
Boost Filter (fs=44.1kHz)
100
Table 38. Bass Boost Control
DEM0
0
1
0
1
BST0
0
1
0
1
Frequency [Hz]
- 49 -
44.1kHz
48kHz
32kHz
Mode
OFF
Mode
MAX
MIN
MID
OFF
1000
Default
Default
10000
[AK4645]
2006/09