max485 pdf datasheet

The MAX481E, MAX483E, MAX485E, MAX487E–MAX491E,

and MAX1487E are low-power transceivers for RS-485 and

RS-422 communicaTIons in harsh environments. Each driver

output and receiver input is protected against ±15kV electrostaTIc

discharge (ESD) shocks, without latchup. These parts

contain one driver and one receiver. The MAX483E,

MAX487E, MAX488E, and MAX489E feature reduced slewrate

drivers that minimize EMI and reduce reflecTIons caused

by improperly terminated cables, thus allowing error-free

data transmission up to 250kbps. The driver slew rates of the

MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E

are not limited, allowing them to transmit up to 2.5Mbps.

These transceivers draw as little as 120μA supply current

when unloaded or when fully loaded with disabled drivers

(see SelecTIon Table). Additionally, the MAX481E,

MAX483E, and MAX487E have a low-current shutdown

mode in which they consume only 0.5μA. All parts operate

from a single +5V supply.

Drivers are short-circuit current limited, and are protected

against excessive power dissipation by thermal shutdown

circuitry that places their outputs into a high-impedance

state. The receiver input has a fail-safe feature that guarantees

a logic-high output if the input is open circuit.

The MAX487E and MAX1487E feature quarter-unit-load

receiver input impedance, allowing up to 128 transceivers

on the bus. The MAX488E–MAX491E are designed for fullduplex

communications, while the MAX481E, MAX483E,

MAX485E, MAX487E, and MAX1487E are designed for halfduplex

applications. For applications that are not ESD sensitive

see the pin- and function-compatible MAX481,

MAX483, MAX485, MAX487–MAX491, and MAX1487.

________________________Applications

Low-Power RS-485 Transceivers

Low-Power RS-422 Transceivers

Level Translators

Transceivers for EMI-Sensitive Applications

Industrial-Control Local Area Networks