AVAILABLE

Functional Diagrams

Pin Configurations appear at end of data sheet.

Functional Diagrams continued at end of data sheet.

UCSP is a trademark of Maxim Integrated Products, Inc.

For pricing, delivery, and ordering information, please contact Maxim Direct

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

General Description

The MAX481, MAX483, MAX485, MAX487–MAX491, and

MAX1487 are low-power transceivers for RS-485 and RS-

422 communication. Each part contains one driver and one

receiver. The MAX483, MAX487, MAX488, and MAX489

feature reduced slew-rate 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 MAX481, MAX485, MAX490,

MAX491, and MAX1487 are not limited, allowing them to

transmit up to 2.5Mbps.

These transceivers draw between 120µA and 500µA of

supply current when unloaded or fully loaded with disabled

drivers. Additionally, the MAX481, MAX483, and MAX487

have a low-current shutdown mode in which they consume

only 0.1µA. 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 the driver outputs into a high-imped-

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

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

The MAX487 and MAX1487 feature quarter-unit-load

receiver input impedance, allowing up to 128 MAX487/

MAX1487 transceivers on the bus. Full-duplex communi-

cations are obtained using the MAX488–MAX491, while

the MAX481, MAX483, MAX485, MAX487, and MAX1487

are designed for half-duplex applications.

________________________Applications

Low-Power RS-485 Transceivers

Low-Power RS-422 Transceivers

Level Translators

Transceivers for EMI-Sensitive Applications

Industrial-Control Local Area Networks

__Next Generation Device Features

♦♦ For Fault-Tolerant Applications

MAX3430: ±80V Fault-Protected, Fail-Safe, 1/4

Unit Load, +3.3V, RS-485 Transceiver

MAX3440E–MAX3444E: ±15kV ESD-Protected,

±60V Fault-Protected, 10Mbps, Fail-Safe,

RS-485/J1708 Transceivers

♦♦ For Space-Constrained Applications

MAX3460–MAX3464: +5V, Fail-Safe, 20Mbps,

Profibus RS-485/RS-422 Transceivers

MAX3362: +3.3V, High-Speed, RS-485/RS-422

Transceiver in a SOT23 Package

MAX3280E–MAX3284E: ±15kV ESD-Protected,

52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422,

True Fail-Safe Receivers

MAX3293/MAX3294/MAX3295: 20Mbps, +3.3V,

SOT23, RS-485/RS-422 Transmitters

♦♦ For Multiple Transceiver Applications

MAX3030E–MAX3033E: ±15kV ESD-Protected,

+3.3V, Quad RS-422 Transmitters

♦♦ For Fail-Safe Applications

MAX3080–MAX3089: Fail-Safe, High-Speed

(10Mbps), Slew-Rate-Limited RS-485/RS-422

Transceivers

♦♦ For Low-Voltage Applications

MAX3483E/MAX3485E/MAX3486E/MAX3488E/

MAX3490E/MAX3491E: +3.3V Powered, ±15kV

ESD-Protected, 12Mbps, Slew-Rate-Limited,

True RS-485/RS-422 Transceivers

Low-Power, Slew-Rate-Limited

RS-485/RS-422 Transceivers

______________________________________________________________Selection Table

PART

NUMBER

HALF/FULL

DUPLEX

DATA

RATE

(Mbps)

SLEW-RATE

LIMITED

LOW-

POWER

SHUTDOWN

RECEIVER/

DRIVER

ENABLE

QUIESCENT

CURRENT

(μA)

NUMBER OF

RECEIVERS ON

BUS

PIN

COUNT

MAX481

Half

2.5

No

Yes

Yes

300

32

8

MAX483

Half

0.25

Yes

Yes

Yes

120

32

8

MAX485

Half

2.5

No

No

Yes

300

32

8

MAX487

Half

0.25

Yes

Yes

Yes

120

128

8

MAX488

Full

0.25

Yes

No

No

120

32

8

MAX489

Full

0.25

Yes

No

Yes

120

32

14

MAX490

Full

2.5

No

No

No

300

32

8

MAX491

Full

2.5

No

No

Yes

300

32

14

MAX1487

Half

2.5

No

No

Yes

230

128

8

Ordering Information appears at end of data sheet.

______________________________________________________________Selection Table

19-0122; Rev 9; 9/09

MAX481/MAX483/MAX485/

MAX487–MAX491/MAX1487