AK4955 Datasheet, PDF (13/117 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/SPK/Cap-less VIDEO-AMP/ LDO & DSP

[AK4955]
FILTER CHARACTERISTICS
(Ta =25°C; AVDD=2.7 ∼ 3.6V, DVDD = 1.6 ~ 2.0V, LVDD = 2.7 ~ 5.5V, SVDD= 2.7 ~ 5.5V, TVDD = DVDD-0.2 ∼
3.6V; fs=48kHz, DEM= OFF)
Parameter
Symbol
min
typ
max
Unit
ADC Digital Filter (Decimation LPF):
Passband (Note 29)
±0.16dB
PB
0
-
18.8
kHz
−0.66dB
-
21.1
-
kHz
−1.1dB
−6.9dB
-
21.7
-
kHz
-
24.1
-
kHz
Stopband (Note 29)
SB
28.4
-
-
kHz
Passband Ripple
PR
-
-
±0.16
dB
Stopband Attenuation
SA
73
-
-
dB
Group Delay (Note 30)
GD
-
16
-
1/fs
Group Delay Distortion
ΔGD
-
0
-
μs
ADC Digital Filter (HPF): HPFC1-0 bits = “00”
Frequency Response
−3.0dB
FR
-
3.7
-
Hz
(Note 29)
−0.5dB
−0.1dB
-
10.9
-
Hz
-
23.9
-
Hz
DAC Digital Filter (LPF):
Passband (Note 29)
±0.05dB
PB
0
−6.0dB
-
-
21.8
kHz
24
-
kHz
Stopband (Note 29)
SB
26.2
-
-
kHz
Passband Ripple
PR
-
-
±0.05
dB
Stopband Attenuation
SA
54
-
-
dB
Group Delay (Note 30)
GD
-
22
-
1/fs
DAC Digital Filter (LPF) + SCF:
Frequency Response: 0 ∼ 20.0kHz
FR
-
±1.0
-
dB
Note 29. The passband and stopband frequencies scale with fs (system sampling rate). Each response refers to that of
1kHz. For example, it is 0.454 x fs (ADC) when PB=21.7kHz (@−1.1dB).
Note 30. A calculating delay time which is induced by digital filtering. This time is from the input of an analog signal to
the setting of 24-bit data of both channels to the ADC output register. For the DAC, this time is from setting the
24-bit data of a channel from the input register to the output of analog signal. For the signal through the block
controlled by PMPFIL bit, the group delay is increased by 4/fs (typ) at ADC block, by 7/fs (typ) at DAC block
from the value above in both recording and playback modes if there is no phase change by the IIR filter. The
group delay is increased more for the signal through the block controlled by PMDSP bit.
MS1343-E-00
- 13 -
2011/12