1/11

November 2002

s

LOW SUPPLY CURRENT: 5mA MAX

s

-7 TO 12 COMMON MODE INPUT VOLTAGE

RANGE

s

70mV TYPICAL INPUT HYSTERESIS

s

DESIGNED FOR 25Mbps OPERATION

s

OPERATE FROM SINGLE 5 SUPPLY

s

±4kV ESD PROTECTION

s

CURRENT LIMITING AND THERMAL

SHUTDOWN FOR DRIVER OVERLOAD

PROTECTION

DESCRIPTION

The ST490A is a low power transceiver for

RS-485 and RS-422 communications. The device

contains one driver and one receiver in full duplex

configuration. The ST490A draws 5mA (typ.) of

supply current when unloaded or fully loaded with

disabled drivers. It operates from a single 5V

supply.

Driver is short-circuit current limited and is

protected against excessive power dissipation by

thermal shutdown circuitry that place the driver

outputs into a high-impedance state. The receiver

input has a fail-safe feature that guarantees a

logic high output if both inputs are open circuit.

ORDERING CODES

Type

Temperature

Range

Package

Comments

ST490ACN

0 to 70 °C

DIP-8

50parts per tube / 40tube per box

ST490ABN

-40 to 85 °C

DIP-8

50parts per tube / 40tube per box

ST490ACD

0 to 70 °C

SO-8 (Tube)

100parts per tube / 20tube per box

ST490ABD

-40 to 85 °C

SO-8 (Tube)

100parts per tube / 20tube per box

ST490ACDR

0 to 70 °C

SO-8 (Tape & Reel)

2500 parts per reel

ST490ABDR

-40 to 85 °C

SO-8 (Tape & Reel)

2500 parts per reel

ST490A

LOW POWER HIGH SPEED RS-485/RS-422 TRANSCEIVER

DIP

SOP