ASAHI KASEI
[AK7712A-VT]
Digital Filter Characteristics
This data is not the guaranteed characteristic value but the designed value as a reference.
ADC unit :
(Ta=25°C;VA,VD,VB=5.0V±5%; fs=44.1kHz)
Parameter
(±0.06dB)
( -6.0 dB)
Symbol
PB
min
0
typ
max
20.00
22.05
Units
kHz
kHz
kHz
dB
Passband
Stopband
(note 1)
(note 1)
0
SB
PR
24.35
Passband ripple
(note 2)
±0.005
Stopband attenuation
Group delay distortion
Group delay
(note 3,4)
SR
80
dB
∆GD
GD
0
us
(Ts=1/fs)
29.3
Ts
note 1:The frequencies of passband/stopband are proportional to the sampling frequency (fs).
2: Passband is DC to 19.75kHz at fs=44.1kHz.
3: Stopband is 27.56kHz to 2.795MHz at fs=44.1kHz.
4:The analog modulator samples the input at 2.8224MHz for fs=44.1kHz.There is no rejection of
input signals at those band width which are multiples of the sampling frequency(n x 2.8224MHz
…
±20.21kHz; n=0,1,2,3 ).
DAC unit :
(Ta=25°C;VA,VD,VB=5.0V±5%; fs=44.1kHz;)
Parameter
Digital filter
Symbol
PB
min
typ
max
Units
Passband
( -0.2 dB) (note 1)
( -6.0 dB)
0
-
20.0
-
kHz
kHz
kHz
dB
22.05
Stopband
(note 1)
SB
PR
SA
GD
24.3
Passband ripple
±0.05
Stopband attenuation
41
-
dB
Group delay
(Ts = 1/fs) (note 2)
14.7
-
Ts
Digital filter + analog filter
Amplitude characteristics
-
±0.5
-
dB
0 20kHz
note 1:The frequencies of passband/stopband are proportional to the sampling frequency (fs);
PB=0.4535fs(@-0.2dB), SB=0.546fs(@-41dB).
2:The calculating delay time is occurred by digital filtering.This is the time from the setting
20-bit data on input register to the output of analog signal. (at fs=44.1kHz)
0180-E-02
- 14 -
1997/12
AKM [ ASAHI KASEI MICROSYSTEMS ]
