AKD4633-A Datasheet, PDF (23/38 Pages) Asahi Kasei Microsystems – 16bit mono CODEC with MIC/SPK amplifier.

ASAHI KASEI
[AKD4633-A]
8. [Filter Dialog]
It is possible to calculate the coefficients of HPF and EQ filters, write these coefficients to registers and confirm the
frequency response of these filters. Click [Filter] button, then the window as shown in Figure 6 opens.
Figure 6. [Filter] Window
(1) Setup the Parameters
Set up the parameters of HPF and EQ filters.
Parameter
Contents
Sampling Rate
Sampling Frequency (fs)
HPF Cut Off Frequency
High Pass Filter Cut Off Frequency
EQ1 Center Frequency
EQ1 Center Frequency
EQ1 Band Width
EQ1 Band Width
(Note 1)
EQ1 Gain
EQ1 Gain
(Note 2)
EQ2 Center Frequency
EQ2 Center Frequency
EQ2 Band Width
EQ2 Band Width
(Note 1)
EQ2 Gain
EQ2 Gain
(Note 2)
Note 1. Band width of 3dB gain difference from center frequency
Note 2. This filter is notch filter when this gain is -1.
Setup range
48000Hz ≥ fs ≥ 7350Hz
(fs/2 – 1) ≥ fc > fs/10000
fs/2 ≥ EQ1 > 0Hz
fs/2 ≥ EQ1 >1Hz
3 > EQ1 ≥- 1
fs/2 ≥ EQ2 > 0Hz
fs/2 ≥ EQ2 >1Hz
3 > EQ2 ≥- 1
(2) Filter ON/OFF
Set up the ON or OFF of filters by the check button of "HPFAD", "HPF", "EQ1" and "EQ2". The filter is ON when the
button is checked.
Figure 7. Filter ON/OFF check button
<KM079406>
- 23 -
2007/04