DE is low for 200ns (typ), the devices are guaranteed to
enter shutdown.
Enable times t
ZH
and t
ZL
(see the
Switching Character-
istics
) assume the devices are not in a low-power shut-
down state. Enable times t
ZH(SHDN)
and t
ZL(SHDN)
assume the devices are in a shutdown state. It takes dri-
vers 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
).
Line Length
The RS-485 standard covers line lengths up to 4000ft.
For line lengths greater than 4000ft, use the repeater
application shown in Figure 8.
Typical Applications
The MAX13181E–MAX13184E transceivers are designed
for bidirectional data communications on multipoint bus
transmission lines. The MAX13181E/MAX13183E can be
used in either half-duplex or full-duplex configuration.
The MAX13182E/MAX13184E are for full-duplex only.
Figure 9 shows the typical network application circuit for
half-duplex, and Figures 10 and 11 show typical network
application circuits for full duplex.
To minimize reflections, terminate the line at both ends in
its characteristics impedance, and keep stub lengths off
the main line as short as possible. The slew-rate-limited
MAX13181E/MAX13182E are more tolerant of imperfect
termination.
MAX13181E–MAX13184E
+5.0V, ±15kV ESD-Protected, Half-Duplex/
Full-Duplex, RS-485 Transceiver in µDFN
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