CDB42438 Cirrus Logic Inc, CDB42438 Datasheet - Page 52

• Manufacturer Part Number: CDB42438
• Description: Eval Bd 108dB 6&8ch Multi-Chnl CODECs
• Manufacturer: Cirrus Logic Inc

Specifications of CDB42438

• Main Purpose: Audio, CODEC
• Embedded: Yes, FPGA / CPLD
• Utilized Ic / Part: CS42438
• Primary Attributes: 6 Single-Ended and 2 Differential Analog Inputs and 8 Outputs, S/PDIF Transmitter and Receiver
• Secondary Attributes: Graphic User Interface
• Description/function: Audio CODECs
• Operating Supply Voltage: 5 V to 12 V
• Product: Audio Modules
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: CS42438
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant, Contains lead / RoHS non-compliant
• Other names: 598-1500

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8.1.2
Passive Input Filter w/Attenuation
Some applications may require signal attenuation prior to the ADC. The full-scale input voltage will scale
with the analog power supply voltage. For VA = 5.0 V, the full-scale input voltage is approximately
2.8 Vpp, or 1 Vrms (most consumer audio line-level outputs range from 1.5 to 2 Vrms).
Figure 23
pedance on the analog inputs, the full distortion performance cannot be realized. Also, the resistor divider
circuit will determine the input impedance into the input filter. In the circuit shown in
impedance is approximately 5 kΩ. By doubling the resistor values, the input impedance will increase to
10 kΩ. However, in this case the distortion performance will drop due to the increase in series resistance
on the analog inputs.
shows a passive input filter with 6 dB of signal attenuation. Due to the relatively high input im-
Figure 23. Passive Input Filter w/Attenuation
2.5 kΩ
2.5 kΩ
2.5 kΩ
2.5 k
2.5 k
2.5 k
Ω
Ω
Ω
4.7 μF
10 μF
10 μF
10 μF
2700 pF
2700 pF
2700 pF
C0G
C0G
C0G
AIN1+,2+,3+,4+
AIN1-,2-,3-,4-
AIN5A,6A
AIN5B,6B
ADC1-2
ADC3
Figure
CS42438
23, the input
DS646F2