AK7755EN_16 Datasheet, PDF (18/109 Pages) Asahi Kasei Microsystems – DSP with Mono ADC Stereo CODEC + Mic/Lineout Amp

[AK7755]
■ Digital Filter Characteritics
1. ADC
(Ta= -40 to 85C; AVDD=3.0 to 3.6V, TVDD=1.7 to 3.6V, DVDD=1.14 to 1.3V, AVSS=DVSS=0V,
fs=48kHz (Note 26))
Parameter
Symbol
min
typ
max
Unit
Passband +0.14dB ~ 0.12dB
PB
0
(Note 27)
-0.87dB
20.7
kHz
21.6
kHz
-3.0dB
22.8
kHz
Stoppband
SB
28.4
kHz
Passband Ripple
(Note 27) _PR
±0.14
dB
Stopband Ripple (Note 28, Note 29) SA
65
dB
Group Delay Distorsion
△GD
0
μs
Group Daley
(Ts=1/fs)
GD
12.5
Ts
Note 26. The passband and stopband frequencies scale with “fs” (system sampling rate). The characteristic
of the high pass filter is not included.
Note 27. The passband is from DC to 18.9kHz when fs=48kHz.
Note 28. The stopband is 28kHz to 3.044MHz when fs=48kHz.
Note 29. When fs = 48kHz, the analog modulator samples the input signal at 3.072MHz. There is no
attenuation of an input signal in band (n x 3.072MHz ±21.99kHz; n=0, 1, 2, 3…) of integer times
of the sampling frequency by the digital filter.
2. DAC
(Ta= -40 to 85C; AVDD=3.0 to 3.6V, TVDD=1.7 to 3.6V, DVDD=1.14 to 1.3V, AVSS=DVSS=0V,
fs=48kHz)
Parameter
Symbol
min
Typ
max
Unit
Passband (Note 30) (±0.05dB)
PB
0
21.7
kHz
(-6.0dB)
24
kHz
Stopband (Note 30)
SB
26.2
kHz
Passband Ripple
PR
±0.05
dB
Stopband Attenuation
SA
64
dB
Group Delay (Ts=1/fs) (Note 31)
GD
24
Ts
Digital Filter + Analog Filter
Amplitude Characteristics 20Hz to 20.0kHz
±0.5
dB
Note 30. The passband and stopband frequencies are proportional to “fs” (system sampling rate), and
represents PB=0.4535 × fs(@0.05dB) and SB=0.5465 × fs, respectively.
Note 31. The digital filter delay is calculated as the time from setting data into the input register until an
analog signal is output.
014006643-E-00
- 18 -
2014/10