1

Rev. 10/11/02

SP3490/3491 Low Power Full-Duplex RS485 Transceivers

© Copyright 2002 Sipex Corporation

■ Full Duplex RS-485 and RS-422

Transceivers

■ Operates from a single +3.3V supply

■ Interoperable with +5.0V logic

■ Driver/Receiver Tri-state Enable

Lines (SP3491)

■ -7V to +12V Common-Mode Input

Voltage Range

■ +200mV Receiver Input Sensitivity

■ Allows up to 32 transceivers on

the serial bus

■ Compatibility with LTC490

and SN75179 (SP3490)

■ Compatibility with LTC491

and SN75180 (SP3491)

SP3490/SP3491

DESCRIPTION

The SP3490 and the SP3491 are +3.3V low power full duplex transceivers that meet the

specifications of the RS-485 and RS-422 serial protocols. These devices are pin-to-pin

compatible with the Sipex SP490 and SP491 devices as well as popular industry standards.

The SP3490 and the SP3491 feature Sipex's BiCMOS process, allowing low power operation

without sacrificing performance. The SP3490 and SP3491 meet the electrical specifications

of RS-485 and RS-422 serial protocols up to 10Mbps under load. The SP3491 is identical to

the SP3490 with the addition of driver and receiver tri-state enable lines.

6

1

2

3

4

5

7

8

Vcc

GND

R

D

A

B

Z

Y

R

D

9

10

11

12

13

14

NC

REB

DE

GND

NC

NC

1

2

3

4

5

6

7

8

R

D

Vcc

GND

R

D

A

B

Z

Y

SP3490

SP3491

+3.3V Low Power Full Duplex RS-485

Transceivers with 10Mbps Data Rate

®