Datasheet

Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491
Rev. E | Page 15 of 20
LINE LENGTH vs. DATA RATE
The RS-485 and RS-422 standards cover line lengths up to 4000 feet. For line lengths greater than 4000 feet, see Figure 36.
B
A
R
D
RO
RE
DI
DE
ADM3483/
ADM3485
ADM3483/
ADM3485
ADM3483/
ADM3485
ADM3483/
ADM3485
B
A
R
D
RO
RE
DI
DE
B
A
R
D
RO
RE DI
DE
B
A
R
D
RO
RE
DI
DE
05524-022
MA
X
IMUM NUMBER OF TRANSCEI
V
ERS ON BUS = 32
R
T
R
T
NOTES
1. R
T
IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE.
V
CC
R1
R2
Figure 32. ADM3483/ADM3485 Typical Half-Duplex RS-485 Network
R
D
RO
RE
DI
DE
ADM3491
ADM3491
A
B
Z
Y
05524-090
R
D
RO DIDE
A B Z Y
RE
R
D
RO
DI
DE
ADM3491
MASTER
SLAVE
SLAVE
A
B
Z
Y
RE
MAXIMUM NUMBER OF NODES = 32
ADM3491
R
D
RO DIDE
A B Z Y
RE
SLAVE
NOTES
1.
R
T
IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE.
R
T
R
T
R
T
V
CC
R1
R2
R
T
V
CC
R1
R2
Figure 33. ADM3491 Typical Full-Duplex RS-485 Network