DS89C387

Twelve Channel CMOS Differential Line Driver

General Description

The DS89C387 is a high speed twelve channel CMOS differ-

ential driver that meets the requirements of TIA/EIA-422-B.

The DS89C387 features a low I

maximum, which makes it ideal for battery powered and

power conscious applications. The device replaces three

DS34C87s and offers a PC board space savings up to 30%.

The twelve channel driver is available in a SSOP package.

The device is ideal for wide parallel bus applications.

be active or in a HI-impedance off state. Each enable is com-

mon to only two drivers for flexibility and control. The drivers

may be disabled to turn off load current and to save power

when data is not being transmitted.

The driver’s input (DI) is compatible with both TTL and

CMOS signal levels.

Features

n Meets TIA/EIA-422-B (RS-422)

n Guaranteed AC parameters:

— Maximum driver skew

−3 ns

— Maximum transition time

−10 ns

n Available in SSOP packaging:

— Requires 30% less PCB space than 3 DS34C87TMs

Connection Diagram

Functional Diagram

Truth Table

Enable

Input

Outputs

EN

DI

DO

LX

Z

Z

HH

H

L

HL

L

H

48L SSOP

DS89C387

DS012086-1

Order Number DS89C387TMEA

See NS Package Number MS48A

DS012086-2

1/6 of package

May 1995

© 1998 National Semiconductor Corporation

DS012086

www.national.com