ak4564 AKM Semiconductor, Inc., ak4564 Datasheet - Page 26

• Manufacturer Part Number: ak4564
• Description: 16bit Codec With Built-in Alc And Mic/hp/spk-amp
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
n Digital EQ/HPF/LPF Circuits
The AK4564 performs equalizing, filtering and ALC (Automatic Level Control) by digital domain for A/D converter
data. The equalizing circuit emphasizes stereo separation when using internal microphone. LPF1, LPF2 and HPF2 are IIR
filters of 1
wind-noise. Refer to the section of “ALC1 operation” about ALC1.
MS0140-E-01
Lch
Rch
st
order to compensate frequency response of microphone and etc. HPF3 is IIR filter of 2
wind-noise cut
HPF3
HPF3
LPF1
LPF1
Filtering
LPF2
LPF2
Figure 21. Digital EQ/HPF/LPF
HPF2
HPF2
- 26 -
Main
Main
HPF1
HPF1
Equalizing
Sub
Sub
MIX
MIX
+
+
ALC1
ALC1
nd
order to cut a
Lch
Rch
[AK4564]
2002/07