_________________General Description

The MAX1480A/MAX1480B/MAX1480C/MAX1490A/

MAX1490B are complete, electrically isolated, RS-485/

RS-422 data-communications interface solutions in a

hybrid microcircuit. Transceivers, optocouplers, and a

transformer provide a complete interface in a standard

DIP package. A single +5V supply on the logic side pow-

ers both sides of the interface.

The MAX1480B/MAX1480C/MAX1490B feature reduced-

slew-rate drivers that minimize EMI and reduce reflec-

tions caused by improperly terminated cables, allowing

error-free data transmission at data rates up to 250kbps.

The MAX1480A/MAX1490A driver slew rate is not limited,

allowing transmission rates up to 2.5Mbps. The

MAX1480A/B/C are designed for half-duplex communi-

cation, while the MAX1490A/B feature full-duplex com-

munication.

Drivers are short-circuit current limited and protected

against excessive power dissipation by thermal shut-

down circuitry that places the driver outputs into a high-

impedance state. The receiver input has a fail-safe

feature that guarantees a known output (RO low for the

MAX1480A/B/C, RO high for the MAX1490A/B/C) if the

input is open circuit.

The MAX1480A/MAX1480B/MAX1480C/MAX1490A/

RS-485/RS-422 specifications. The MAX1480A/B/C are

available in a 28-pin DIP package, and the MAX1490A/B

are available in a 24-pin DIP package.

________________________Applications

Isolated RS-485/RS-422 Data Interface

Transceivers for EMI-Sensitive Applications

Industrial-Control Local Area Networks

Automatic Test Equipment

HVAC/Building Control Networks

Next-Generation Device Features

o For Integrated ESD Protection

MAX1480E/MAX1490E: ±15kV ESD-Protected,

Isolated RS-485/RS-422 Data Interfaces

o For Space-Constrained Applications

MAX3157: High CMRR, RS-485 Transceiver with

±50V Isolation

Complete, Isolated RS-485/RS-422

Data Interface

________________________________________________________________ Maxim Integrated Products

1

1

24

23

22

21

20

19

18

17

2

3

4

5

6

7

8

AC1

AC2

ISO RO DRV

D2

D1

A

B

Z

Y

SD

FS

GND1

16

15

14

13

9

10

11

12

ISO COM1

ISO DI DRV

ISO RO LED

GND2

RO

DI

DIP

MAX1490A/B

TOP VIEW

ISOLATION BARRIER

Pin Configurations

19-0259; Rev 5; 5/05

_______________Ordering Information

Ordering Information continued at end of data sheet.

“C” parts is up to 250kbps.

Pin Configurations continued at end of data sheet.

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

TEMP RANGE

PIN-PACKAGE

MAX1480ACPI

0°C to +70°C

28 Wide Plastic DIP

MAX1480AEPI

-40°C to +85°C

28 Wide Plastic DIP

_____________________Selection Table

PART

HALF/

FULL

DUPLEX

DATA

RATE

(MBPS)

SLEW-

RATE

LIMITED

DRIVER

ENABLE

TIME

(µS)

MAX1480A

Half

2.5

No

0.2

MAX1480B

Half

0.25

Yes

35

MAX1480C

Half

0.25

Yes

0.5

MAX1490A

Full

2.5

No

—

MAX1490B

Full

0.25

Yes

—