[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)
PB
0
-
-
-
-
21.1
21.7
24.1
-
-
-
16
0
18.8
-
-
-
kHz
kHz
kHz
kHz
kHz
dB
dB
1/fs
μs
±0.16dB
−0.66dB
−1.1dB
−6.9dB
Stopband (Note 29)
Passband Ripple
Stopband Attenuation
Group Delay (Note 30)
Group Delay Distortion
SB
PR
SA
GD
ΔGD
28.4
-
-
73
-
±0.16
-
-
-
-
ADC Digital Filter (HPF): HPFC1-0 bits = “00”
Frequency Response
(Note 29)
FR
-
-
-
3.7
10.9
23.9
-
-
-
Hz
Hz
Hz
−3.0dB
−0.5dB
−0.1dB
DAC Digital Filter (LPF):
Passband (Note 29)
PB
0
-
24
-
-
-
21.8
-
-
±0.05
-
-
kHz
kHz
kHz
dB
dB
1/fs
±0.05dB
−6.0dB
-
26.2
-
54
-
Stopband (Note 29)
Passband Ripple
Stopband Attenuation
Group Delay (Note 30)
SB
PR
SA
GD
22
DAC Digital Filter (LPF) + SCF:
FR
-
-
dB
Frequency Response: 0 ∼ 20.0kHz
±1.0
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
2011/12
- 13 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
