CS42448-CQZR Cirrus Logic Inc, CS42448-CQZR Datasheet - Page 53

• Manufacturer Part Number: CS42448-CQZR
• Description: IC,Soundcard Circuits,CMOS,QFP,64PIN,PLASTIC
• Manufacturer: Cirrus Logic Inc

DS648F2
7. EXTERNAL FILTERS
7.1
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 mul-
tiples of the digital passband frequency (n
a recommended analog input filter that will attenuate any noise energy at 6.144 MHz, in addition to providing
the optimum source impedance for the modulators. Refer to
count passive input filters. The use of capacitors that have a large voltage coefficient (such as general-pur-
pose ceramics) must be avoided since these can degrade signal linearity
100 k Ω
100 k Ω
100 k Ω
4.7 μF
VA
Figure 26. Single to Differential Active Input Filter
100 kΩ
100 kΩ
0.1 μF
100 kΩ
10 k Ω
Figure 27. Single-Ended Active Input Filter
-
+
4.7 μF
4.7 μF
4.7 μF
470 pF
100 μF
C0G
100 kΩ
100 kΩ
100 kΩ
100 kΩ
100 kΩ
100 kΩ
VA
VA
VA
332 Ω
634 Ω
634 Ω
91 Ω
×
+
-
+
-
+
-
6.144 MHz), where n=0,1,2,... Refer to
470 pF
470 pF
470 pF
C0G
C0G
C0G
-
+
470 pF
C0G
634 Ω
634 Ω
634 Ω
91 Ω
91 Ω
91 Ω
634 Ω
Figures 28
4.7 μF
91 Ω
2700 pF
2700 pF
2700 pF
C0G
C0G
C0G
AIN1+,2+,3+,4+
AIN1-,2-,3-,4-
AIN5A,6A
AIN5B,6B
2700 pF
and
C0G
ADC1-2
ADC3
29
for low-cost, low-component-
AINx+
AINx-
Figures 26
ADC1-3
CS42448
and
27
for
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