AK7714 Datasheet, PDF (13/48 Pages) Asahi Kasei Microsystems – 20-Bit Audio Codec with DSP and Delay RAM

[ASAHI KASEI]
[AK7714]
(4) Digital filter characteristics
Values described below are design values cited as references. These are not for guaranteeing the characteristics.
1) ADC Section:
(Ta = 25°C; AVDD, DVDD, AVB, DVB = 5.0 V ±5%; fs = 44.1 kHz)
Parameter
Pass band (-0.02 dB)
(-6.0 dB)
Stop band
(Note 1)
Pass band ripple
(Note 2)
Stop band attenuation (Notes 3,4)
Group delay distortion
Group delay (Ts = 1/fs)
Symbol
PB
SB
PR
SA
∆GD
GD
Min
0
0
24.35
80
Typ
Max
Unit
20.00
kHz
22.05
kHz
kHz
±0.005
dB
dB
0
µs
29.3
Ts
Note: 1. These frequencies scale with the sampling frequency (fs).
2. The pass band is from DC to 19.75 kHz when fs = 44.1 kHz.
3. The stop band is from 27.56 kHz to 2.795 MHz when fs = 44.1 kHz.
4. When fs = 44.1 kHz, the analog modulator samples analog input at 2.8224 MHz.
The input signal is not attenuate dBy the digital filter in the multiple bands (n x 2.8224 MHz ± 20.21 kHz ;
n = 0, 1, 2, 3...) of the sampling frequency.
2) DAC section
(Ta = 25°C; AVDD, DVDD, AVB, DVB = 5.0 V ±5%; fs = 44.1 kHz)
Parameter
Symbol
Min
Typ
Max
Unit
Digital filter
Pass band ±0.07 dB (Note 1)
PB
0
20.0
kHz
(-6.0 dB)
-
22.05
-
kHz
Stop band
(Note 1)
SB
24.1
kHz
Pass band ripple
PR
±0.07
dB
Stop band attenuation
SA
47
dB
Group delay (Ts = 1/fs ) (Note 2)
GD
-
15.3
Ts
Digital filter + Analog filter
Amplitude characteristics
±0.5
dB
0 to 20.0 kHz
Note: 1. The pass band and stop band frequencies are proportional to "fs" (system sampling rate), and are represente
PB = 0.4535 fs(@ -0.06 dB) and SB = 0.546 fs, respectively.
2. The caluculating delay time which occurred by digital filtering.
This time is from setting the 20-bit data of both channels on input register to the output of analog signal.
M0018-E-00
- 13 -
‘98/07