1

®

FN6061

ISL81485

5V, 30Mbps, RS-485/RS-422 Transceiver

The Intersil ISL81485 is a BiCMOS, 5V powered, single

transceiver that meets both the RS-485 and RS-422

standards for balanced communication, and features a

larger output voltage and higher data rate to benefit high

speed applications.

Unlike competitive devices, this Intersil transceiver is

specified for 10% tolerance supplies (4.5V to 5.5V), and it

delivers a much larger worst case differential output voltage

(2.0V compared to the typical 1.5V) over the full supply

range. The increased output voltage translates into longer

reach, or better data integrity, at the 30Mbps data rate.

This device presents a “1 unit load” to the RS-485 bus,

which allows up to 32 transceivers on the network.

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

which ensures a logic high Rx output if Rx inputs are

floating.

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.

Features

• Specified for 10% Tolerance Supplies

• High Data Rates . . . . . . . . . . . . . . . . . . . . . up to 30Mbps

• Large Differential Output Voltage. . . . 2.0V(min.) into 54

Ω

• Drop-In Replacement for the ADM1485

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

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

• Three State Rx and Tx Outputs

• 15ns (Max) Propagation Delays, 5ns (Max) Skew

• Operates from a Single +5V Supply (10% Tolerance)

• Current Limiting and Thermal Shutdown for driver

Overload Protection

Applications

• SCSI “Fast 20” Drivers and Receivers

• Factory Automation

• Field Bus Networks

• Security Networks

• Building Environmental Control Systems

• Industrial/Process Control Networks

Ordering Information

PART NO.

(BRAND)

TEMP.

PACKAGE

PKG. DWG. #

ISL81485IB

(81485IB)

-40 to 85

8 Ld SOIC

M8.15

ISL81485IB-T

(81485IB)

-40 to 85

8 Ld SOIC

(Tape and Reel)

M8.15

ISL81485IU

(1485)

-40 to 85

8 Ld MSOP

M8.118

ISL81485IU-T

(1485)

-40 to 85

8 Ld MSOP

(Tape and Reel)

M8.118

Pinout

ISL81485 (SOIC, MSOP)

TOP VIEW

RO

RE

DE

DI

1

2

3

4

8

7

6

5

B / Z

A / Y

GND

D

R

Data Sheet

December 2003

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. All Rights Reserved

All other trademarks mentioned are the property of their respective owners.