AK7740ET Datasheet, PDF (10/48 Pages) Asahi Kasei Microsystems – 24bit 2ch ADC + 24bit 4ch DAC with Audio DSP

[ASAHI KASEI]
[AK7740ET]
(4) Digital filter characteristics
Values described below are design values, cited for reference.
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 is not included
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 modulator samples the analog input at 3.072MHz. The input signal is not attenuated by
the digital filter in 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. Pass band and stop band frequencies are proportional to "fs" (system sampling rate), and are equal to PB =
0.4535fs (@-0.06dB) and SB = 0.546fs, respectively.
2. Calculated delay time in the digital filter from setting the 24-bit data of both channels on the input data
register to the output of analog signal.
<Pre-E-01>
- 10 -
2006/10