AK7744VT Datasheet, PDF (11/50 Pages) Asahi Kasei Microsystems – 24bit 3ch ADC + 24bit 4ch DAC with Audio DSP

[ASAHI KASEI]
[AK7744]
(4) Digital filter characteristics
Values described below are design values cited as references.
4-1) ADC Section:
(Ta=25°C; AVDD,DVDD =3.0V~3.6V; fs=48kHz; HPF=off)
parameter
Symbol
min
Pass band
(-0.02dB)
PB
0
(-6.0dB)
0
Stop band
(Note 1)
SB
26.5
Pass band ripple
(Note 2)
PR
Stop band attenuation (Note3,4)
SA
80
Group delay distortion
∆GD
Group delay
(Ts=1/fs)
GD
typ
max
Unit
21.768
kHz
24.00
kHz
kHz
±0.005
dB
dB
0
us
29.3
Ts
Note: : HPF response does not include.
1. The stop band is from 26.5kHz to 3.0455MHz when fs = 48kHz.
2. The pass band is from DC to 21.5kHz from DC when fs = 48kHz.
3. When fs = 48kHz, the analog modulator samples analog input at 3.072MHz. The digital filter does not
attenuate the input signal in the multiple bands (n x 3.072MHz ± 21.99kHz; n=0, 1, 2, 3...) of the sampling
frequency.
4-2) DAC section
(Ta=25°C; AVDD,DVDD =3.0V~3.6V; fs=48kHz)
parameter
Symbol
min
Digital filter
Pass band ±0.07dB (Note 1)
PB
0
(-6.0dB)
-
Stop band
(Note 1)
SB
26.2
Pass band ripple
PR
Stop band attenuation
SA
47
Group delay
(Note 2)
GD
-
Digital filter+SCF
Amplitude characteristics
0~20.0kHz
Typ
max
Unit
21.7
kHz
24.0
-
kHz
kHz
±0.07
dB
dB
15
Ts
±0.5
dB
Note:
1. The pass band and stop band frequencies are proportional to "fs" (system sampling rate), and represent
PB=0.4535fs(@-0.06dB) and SB=0.546fs, respectively.
2. This calculated delay time, which occurs in the digital filter, is from setting the 24-bit data of both channels on
input register to the output of analog signal.
<MS0167-E-00>
- 11 -
2002/10