CS42516_05 Datasheet, PDF (73/91 Pages) Cirrus Logic – 110 dB, 192 kHz 6-Ch Codec with S/PDIF Receiver

8. APPENDIX A: EXTERNAL FILTERS
CS42516
8.1 ADC Input Filter
The analog modulator samples the input at 6.144 MHz (internal MCLK=12.288 MHz). The digital filter will
reject signals within the stopband of the filter. However, there is no rejection for input signals which are
(n × 6.144 MHz) the digital passband frequency, where n=0,1,2,... Refer to Figure 24 for a recommended
analog input buffer that will attenuate any noise energy at 6.144 MHz, in addition to providing the optimum
source impedance for the modulators. The use of capacitors that have a large voltage coefficient (such as
general-purpose ceramics) must be avoided since these can degrade signal linearity.
AINL
100 kΩ
634 Ω
100 µF
470 pF
C0G
-
+
VA
2.8 kΩ
10 kΩ
91 Ω
634 Ω
3.32 kΩ
0.1 µF
100 µF ^{332 Ω}
634 Ω
470 pF
C0G
-
+
91 Ω
2700 pF
C0G
A INL1+
A INL1-
AINR
100 kΩ
634 Ω
100 µF
470 pF
C0G
-
+
VA
2.8 kΩ
10 kΩ
91 Ω
634 Ω
3.32 kΩ
0.1 µF
100 µF ^{332 Ω}
634 Ω
470 pF
C0G
-
+
91 Ω
2700 pF
C0G
A INR1+
A INR1-
Figure 24. Recommended Analog Input Buffer
8.2 DAC Output Filter
The CS42516 is a linear phase design and does not include phase or amplitude compensation for an exter-
nal filter. Therefore, the DAC system phase and amplitude response will be dependent on the external an-
alog circuitry.
AOUT -
AOUT +
1800 pF
C0G
6.19 kΩ
390 pF
5.49 kΩ 2.94 kΩ
C0G
-
1.65 kΩ
5800 pF
887 Ω
C0G
1.87 kΩ
+
1200 pF
C0G
22 µF
22 µF 1 k Ω
47.5 k Ω
Analog
Out
Figure 25. Recommended Analog Output Buffer
DS583F1
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