1

®

FN6052.3

ISL83483, ISL83485, ISL83488,

ISL83490, ISL83491

3.3V, Low Power, High Speed or Slew Rate

Limited, RS-485/RS-422 Transceivers

These Intersil RS-485/RS-422 devices are BiCMOS 3.3V

powered, single transceivers that meet both the RS-485 and

RS-422 standards for balanced communication. Unlike

competitive devices, this Intersil family is specified for 10%

tolerance supplies (3V to 3.6V).

The ISL83483 and ISL83488 utilize slew rate limited drivers

which reduce EMI, and minimize reflections from improperly

terminated transmission lines, or unterminated stubs in

multidrop and multipoint applications.

Data rates up to 10Mbps are achievable by using the

ISL83485, ISL83490, or ISL83491, which feature higher

slew rates.

Logic inputs (e.g., DI and DE) accept signals in excess of

5.5V, making them compatible with 5V logic families.

Receiver (Rx) inputs feature a “fail-safe if open” design,

which ensures a logic high output if Rx inputs are floating. All

devices present a “single unit load” to the RS-485 bus, which

allows up to 32 transceivers on the network.

Driver (Tx) outputs are short circuit protected, even for

voltages exceeding the power supply voltage. Additionally,

on-chip thermal shutdown circuitry disables the Tx outputs to

prevent damage if power dissipation becomes excessive.

The ISL83488, ISL83490, ISL83491 are configured for full

duplex (separate Rx input and Tx output pins) applications.

The ISL83488 and ISL83490 are offered in space saving 8

lead packages for applications not requiring Rx and Tx

output disable functions (e.g., point-to-point and RS-422).

Half duplex configurations (ISL83483, ISL83485) multiplex

the Rx inputs and Tx outputs to provide transceivers with Rx

and Tx disable functions in 8 lead packages.

Features

• Operate from a Single +3.3V Supply (10% Tolerance)

• Interoperable with 5V Logic

• High Data Rates . . . . . . . . . . . . . . . . . . . . . up to 10Mbps

• Single Unit Load Allows up to 32 Devices on the Bus

• Slew Rate Limited Versions for Error Free Data

Transmission (ISL83483, ISL83488) . . . . . .up to 250kbps

• Low Current Shutdown Mode (ISL83483, ISL83485,

ISL83491). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15nA

• -7V to +12V Common Mode Input Voltage Range

• Three State Rx and Tx Outputs (Except ISL83488,

ISL83490)

• 10ns Propagation Delay, 1ns Skew (ISL83485, ISL83490,

ISL83491)

• Full Duplex and Half Duplex Pinouts

• Current Limiting and Thermal Shutdown for driver

Overload Protection

•

Pb-free available

Applications

• Factory Automation

• Security Networks

• Building Environmental Control Systems

• Industrial/Process Control Networks

• Level Translators (e.g., RS-232 to RS-422)

• RS-232 “Extension Cords”

TABLE 1. SUMMARY OF FEATURES

PART

NUMBER

HALF/FULL

DUPLEX

DATA RATE

(Mbps)

SLEW-RATE

LIMITED?

RECEIVER/DRIVER

ENABLE?

(mA)

LOW POWER

SHUTDOWN?

PIN COUNT

ISL83483

Half

0.25

Yes

Yes

0.65

Yes

8

ISL83485

Half

10

No

Yes

0.65

Yes

8

ISL83488

Full

0.25

Yes

No

0.65

No

8

ISL83490

Full

10

No

No

0.65

No

8

ISL83491

Full

10

No

Yes

0.65

Yes

14

Data Sheet

August 2004

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 321-724-7143

Copyright © Intersil Americas Inc. 2003, 2004. All Rights Reserved

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