MAX13080E Datasheet, PDF (18/24 Pages) Maxim Integrated Products – +5.0V, 15kV ESD-Protected, Fail-Safe, Hot-Swap, RS-485/RS-422 Transceivers

+5.0V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
Low-Power Shutdown Mode (Except
MAX13081E/MAX13084E/MAX13087E)
Low-power shutdown mode is initiated by bringing both
RE high and DE low. In shutdown, the devices typically
draw only 2.8µA of supply current.
RE and DE can be driven simultaneously; the devices
are guaranteed not to enter shutdown if RE is high and
DE is low for less than 50ns. If the inputs are in this
state for at least 700ns, the devices are guaranteed to
enter shutdown.
Enable times t_ZH and t_ZL (see the Switching
Characteristics section) assume the devices were not in
a low-power shutdown state. Enable times t_ZH(SHDN) and
t_ZL(SHDN) assume the devices were in shutdown state. It
takes drivers and receivers longer to become enabled
from low-power shutdown mode (t_ZH(SHDN), t_ZL(SHDN))
than from driver/receiver-disable mode (t_ZH, t_ZL).
RO
RE
R
DE
DI
D
MAX13080E/MAX13081E/MAX13083E/
MAX13084E/MAX13086E/MAX13087E/
MAX13089E (FULL DUPLEX)
A
B 120Ω
DATA IN
Z
Y 120Ω
DATA OUT
Driver Output Protection
Two mechanisms prevent excessive output current and
power dissipation caused by faults or by bus contention.
The first, a foldback current limit on the output stage,
provides immediate protection against short circuits over
the whole common-mode voltage range (see the Typical
Operating Characteristics). The second, a thermal-shut-
down circuit, forces the driver outputs into a high-imped-
ance state if the die temperature exceeds +175°C (typ).
Line Length
The RS-485/RS-422 standard covers line lengths up to
4000ft. For line lengths greater than 4000ft, use the
repeater application shown in Figure 11.
Typical Applications
The MAX13082E/MAX13085E/MAX13088E/MAX13089E
transceivers are designed for bidirectional data commu-
nications on multipoint bus transmission lines. Figures
12 and 13 show typical network applications circuits.
To minimize reflections, terminate the line at both ends
in its characteristic impedance, and keep stub lengths
off the main line as short as possible. The slew-rate-lim-
ited MAX13082E/MAX13085E and the two modes of the
MAX13089E are more tolerant of imperfect termination.
Chip Information
TRANSISTOR COUNT: 1228
PROCESS: BiCMOS
Figure 11. Line Repeater for MAX13080E/MAX13081E/
MAX13083E/MAX13084E/MAX13086E/MAX13087E/MAX13089E
in Full-Duplex Mode
DI
D
120Ω
B
DE
A
B
RO
R
RE
D
MAX13082E
MAX13085E
MAX13088E
MAX13089E (HALF DUPLEX)
DI
Figure 12. Typical Half-Duplex RS-485 Network
A
R
DE RO RE
120Ω
DE
B
B
A
D
DI
A
R
RO
RE
R
D
DI
DE RO RE
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