CS42518 Datasheet, PDF (83/91 Pages) Cirrus Logic – 110 dB, 192 kHz 8-Ch Codec with S/PDIF Receiver

CS42518
13. APPENDIX D: EXTERNAL AES3/SPDIF/IEC60958 RECEIVER COMPONENTS
13.1 AES3 Receiver External Components
The CS42518 AES3 receiver is designed to accept only consumer-standard interfaces. The standards
call for an unbalanced circuit having a receiver impedance of 75 Ω ±5%. The connector is an RCA phono
socket. The receiver circuit is shown in Figure 30. Figure 31 shows an implementation of the Input S/PDIF
Multiplexer using the consumer interface.
In the configuration of systems, it is important to avoid ground loops and DC current flowing down the
shield of the cable that could result when boxes with different ground potentials are connected. Generally,
it is good practice to ground the shield to the chassis of the transmitting unit, and connect the shield
through a capacitor to chassis ground at the receiver. However, in some cases it is advantageous to have
the ground of two boxes held at the same potential, and make the electrical connection through the cable
shield. Generally, it may be a good idea to provide the option of grounding or capacitively coupling the
shield to the chassis.
When more than one RXP pin is driven simultaneously, as shown in Figure 31, there is a potential for
crosstalk between inputs. To minimize this crosstalk, provide as much trace separation as is reasonable
and choose non-adjacent inputs when possible.
The circuit shown in Figure 32 may be used when external RS422 receivers, optical receivers or other
TTL/CMOS logic outputs drive the CS42518 receiver input.
75 Ω
Coax
RCA Phono
75 Ω
0.01 µF
RXP0
75 Ω
Coax
75 Ω
Coax
75 Ω
Coax
.01µF
75 Ω
.01µF
75 Ω
75 Ω
.01µF
RXP7
RX_...P6
RXP0
Figure 30. Consumer Input Circuit
Figure 31. S/PDIF MUX Input Circuit
T T L/C M O S
G ate
0.01 µF
RXP0
Figure 32. TTL/CMOS Input Circuit
DS584PP5
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