_______________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

____________________________Features

♦

In µMAX Package: Smallest 8-Pin SO

♦

Slew-Rate Limited for Error-Free Data

Transmission (MAX483/487/488/489)

♦

0.1µA Low-Current Shutdown Mode

(MAX481/483/487)

♦

Low Quiescent Current:

120µA (MAX483/487/488/489)

230µA (MAX1487)

300µA (MAX481/485/490/491)

♦

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

♦

Three-State Outputs

♦

30ns Propagation Delays, 5ns Skew

(MAX481/485/490/491/1487)

♦

Full-Duplex and Half-Duplex Versions Available

♦

Operate from a Single 5V Supply

♦

Allows up to 128 Transceivers on the Bus

(MAX487/MAX1487)

♦

Current-Limiting and Thermal Shutdown for

Driver Overload Protection

______________Ordering Information

Ordering Information continued at end of data sheet.

* Contact factory for dice specifications.

Low-Power, Slew-Rate-Limited

RS-485/RS-422 Transceivers

________________________________________________________________

www.artschip.com

1

MAX481

MAX483

MAX485

MAX487

MAX488

MAX489

MAX490

MAX491

MAX1487

PART

NUMBER

HALF/FULL

DUPLEX

DATA RATE

(Mbps)

SLEW-RATE

LIMITED

LOW-POWER

SHUTDOWN

RECEIVER/

DRIVER

ENABLE

QUIESCENT

CURRENT

(µA)

NUMBER OF

TRANSMITTERS

ON BUS

PIN

COUNT

Half

Half

Half

Half

Full

Full

Full

Full

Half

2.5

0.25

2.5

0.25

0.25

0.25

2.5

2.5

2.5

No

Yes

No

Yes

Yes

Yes

No

No

No

Yes

Yes

No

Yes

No

No

No

No

No

Yes

Yes

Yes

Yes

No

Yes

No

Yes

Yes

300

120

300

120

120

120

300

300

230

32

32

32

128

32

32

32

32

128

8

8

8

8

8

14

8

14

8

________________________________________________________Selection Table

19-0122; Rev 5; 2/96

PART

TEMP. RANGE

PIN-PACKAGE

MAX481CPA

0°C to +70°C

8 Plastic DIP

MAX481CSA

0°C to +70°C

8 SO

MAX481CUA

0°C to +70°C

8 µMAX

MAX481C/D

0°C to +70°C

Dice*

ARTSCHIP

ARTSCHIP