AK4951AEN Datasheet, PDF (40/105 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/HP/SPK-AMP

[AK4951A]
■ Digital Block
The digital block consists of the blocks shown in Figure 30. Recording path and playback path is selected
by setting ADCPF bit, PFDAC1-0 bits and PFSDO bit (Figure 31 ~ Figure 34, Table 26).
PMADL/R bit
ADC
HPFAD bit
1st Order
HPF1
ADCPF bit
“1” “0”
SDTI
PMPFIL bit
MIC Sens. Correction
AHPF bit
Auto Wind Noise Reduction
HPF bit
1st Order
HPF2
LPF bit
1st Order
LPF
FIL3 bit
Stereo Emphasis
EQ0 bit
GN1-0 bits
Gain Compensation
EQ2-5 bits
4-band
EQ
ALC bit
EQ1 bit
“0” “1”
PFSDO bit
ALC
(Volume)
1-band
EQ
PFVOL
PFDAC1-0 bits
PMDAC bit
Mono/Stereo
DVOL
SMUTE
DAC
SDTO
(1) ADC: Includes the Digital Filter (LPF) for ADC as shown in “Filter Characteristics”.
(2) HPF1: High Pass Filter (HPF) for ADC as shown in “Digital HPF1”.
(3) Microphone Sensitivity Correction: Microphone volume control between L and R channels.
(See “Microphone Sensitivity Correction”)
(4) Automatic Wind Noise Reduction Filter: Automatic HPF
(See “Automatic Wind Noise Reduction Filter”)
(5) HPF2: High Pass Filter. (See “Digital Programmable Filter Circuit”)
(6) LPF: Low Pass Filter (See “Digital Programmable Filter Circuit”)
(7) Stereo Emphasis: Stereo emphasis Filter. (See “Digital Programmable Filter Circuit”)
(8) Gain Compensation: Gain compensation consists of EQ and Gain control. It corrects frequency
response after stereo separation emphasis filter. (See “Digital Programmable Filter Circuit”)
(9) 4 Band EQ: Applicable for use as Equalizer or Notch Filter.
(See “Digital Programmable Filter Circuit”)
(10) ALC (Volume): Digital Volume with ALC Function.
(See “Input Digital Volume (Manual Mode)” and “ALC Operation”)
(11) 1 Band EQ: Applicable for use as Notch Filter (See “Digital Programmable Filter Circuit”)
(12) PFVOL: Sidetone digital volume (See “Sidetone digital Volume”)
(13) Mono/Stereo Switching: Mono/Stereo lineout outputs select from DAC which described in <Mono
Mixing Output> at “DAC Mono/Stereo Mode”.
(14) DVOL: Digital volume for playback path (See “Output Digital Volume”)
(15) SMUTE: Soft mute function (See “Soft Mute”)
Figure 30. Digital Block Path Select
016001936-E-00
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2016/03