ASAHI KASEI
[AK4101A]
n Line Drivers
There are four RS422 line drivers on chip. The AES3 specification states that the line driver shall have a balanced
output with an internal impedance of 110 ohms ±20% and also requires a balanced output drive capability of 2 to 7 volts
peak-to-peak into 110 ohm load. The internal impedance of the RS422 driver along with a series resistors of 56 ohms
realizes this requirement. For consumer use(S/PDIF), the specifications require an output impedance of 75 ohms ±20%
and a driver level of 0.5±20% volts peak to peak. A combination of 330 ohms in parallel with 100 ohms realizes this
requirement. The outputs can be set to ground by resetting the device or a software mute.
56
0.1u
Transformer
TXP
TXN
XLR Connector
Figure 17. Professional Output Driver Circuit
330 0.1u Transformer
TXP
TXN
RCA Phono
Connector
100
Figure 18. Consumer Output Driver Circuit
MS0250-E-00
2003/07
- 20 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
