CS8420-CSZR Cirrus Logic Inc, CS8420-CSZR Datasheet - Page 78

• Manufacturer Part Number: CS8420-CSZR
• Description: IC,Digital Audio Sample Rate Converter,SOP,28PIN
• Manufacturer: Cirrus Logic Inc

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14. EXTERNAL AES3/SPDIF/IEC60958 TRANSMITTER AND RECEIVER
This section details the external components required to interface the AES3 transmitter and receiver to cables and
fiber-optic components.
14.1
COMPONENTS
AES3 Transmitter External Components
The output drivers on the CS8420 are designed to drive both the professional and consumer interfaces. The
AES3 specification for professional/broadcast use calls for a 110 Ω source impedance and a balanced drive
capability. Since the transmitter output impedance is very low, a 110 Ω resistor should be placed in series
with one of the transmit pins. The specifications call for a balanced output drive of 2-7 volts peak-to-peak
into a 110 Ω load with no cable attached. Using the circuit in
circuit protected, has the proper source impedance, and provides a 5 volts peak-to-peak signal into a 110 Ω
load. Lastly, the two output pins should be attached to an XLR connector with male pins and a female shell,
and with pin 1 of the connector grounded.
In the case of consumer use, the IEC60958 specifications call for an unbalanced drive circuit with an output
impedance of 75 Ω and a output drive level of 0.5 V peak-to-peak ±20% when measured across a 75 Ω load
using no cable. The circuit shown in
ance and drive level using standard 1% resistors. The connector for a consumer application would be an
RCA phono socket. This circuit is also short circuit protected.
Figure 30. Professional Output Circuit
CS8420
CS8420
Figure 31. Consumer Output Circuit
TXN
TXN
Figure 31
TXP
TXP
90.9 Ω
374-R
110-(R
only uses the TXP pin and provides the proper output imped-
TXP
TXP
+R
TXN
)
Figure
30, the output of the transformer is short-
1
RCA
Phono
XLR
CS8420
DS245F4