AK4955 Datasheet, PDF (39/117 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/SPK/Cap-less VIDEO-AMP/ LDO & DSP

[AK4955]
■ Digital Block
The digital block consists of the blocks shown in Figure 34. Recording path and playback path are selected by setting
ADCPF bit, PFDAC bit, PFSDO bit and DSPBP bit. (Figure 35 ~Figure 41, Table 24)
PMADL/R bit
ADC
: DSP Block
SDTI
HPFAD bit
1st Order
HPF1
PMPFIL bit
ADCPFbit
“1”
“0”
PMDSP bit
DSP
PMPFIL bit
“0”
“1”
DSPBPbit
HPF bit
1st Order
HPF3
LPF bit
1st Order
LPF
EQ0 bit
GN1-0 bits
Gain
Compensation
EQ5-2 bit
4 Band
EQ
FIL3 bit
ALC bits
EQ1 bit
PMDSP bit
Stereo
Emphasis
ALC
(Volume)
1 Band
EQ
DSP
PMPFIL bit
PMADL/R bit
“0”
“1”
DSPBP bit
“0”
“1”
PFSDO bit
SDTO
PMDAC bit
“0”
“1”
PFDAC bit
DVOL ^{DVOL7-0 bits}
SMUTE ^{SMUTE bit}
Mono/Stero
Switch
De-emphasis
MONO1-0 bits
DEM1-0 bits
DAC
(1) ADC: Includes the Digital Filter (LPF) for ADC as shown in “FILTER CHRACTERISTICS”.
(2) HPF1: High Pass Filter (HPF) for ADC as shown in “Digital HPF1”.
(3) HPF3: High Pass Filter (“Digital Programmable Filter Circuit”)
(4) LPF: Low Pass Filter (See “Digital Programmable Filter Circuit”)
(5) Gain Compensation: Gain compensation consists of EQ and Gain control. It corrects frequency characteristics after
stereo separation emphasis filter. (See “Digital Programmable Filter Circuit”)
(6) 4 Band EQ: Applicable for use as Equalizer or Notch Filter. (See “Digital Programmable Filter Circuit”)
(7) Stereo Emphasis: Stereo emphasis filter (See “Digital Programmable Filter Circuit”)
(8) ALC (Volume): Digital Volume with ALC Function. (See “Input Digital Volume” and “ALC Operation”)
(9) 1 Band EQ: Applicable for use as a Notch Filter (See “Digital Programmable Filter Circuit”)
(10) DVOL: Digital volume for playback path (See “Output Digital Volume2” )
(11) SMUTE: Soft mute function
(12) Mono/Stereo Switching: Mono/Stereo lineout outputs select from DAC which described in <Mono Mixing Output>
at “Stereo Line Outputs”.
(13) De-emphasis: De-emphasis filter (See “De-emphasis Filter Control”)
Figure 34. Digital Block Path Select
MS1343-E-00
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2011/12