DS34C87T

CMOS Quad TRISTATE Differential Line Driver

General Description

The DS34C87T is a quad differential line driver designed for

digital

data

transmission

over

balanced

lines.

The

DS34C87T meets all the requirements of EIA standard

RS-422 while retaining the low power characteristics of

CMOS. This enables the construction of serial and terminal

interfaces while maintaining minimal power consumption.

The DS34C87T accepts TTL or CMOS input levels and

translates these to RS-422 output levels. This part uses spe-

cial output circuitry that enables the individual drivers to

power down without loading down the bus. This device has

separate enable circuitry for each pair of the four drivers.

The DS34C87T is pin compatible to the DS3487T.

All inputs are protected against damage due to electrostatic

discharge by diodes to V

Features

n TTL input compatible

n Typical propagation delays: 6 ns

n Typical output skew: 0.5 ns

n Meets the requirements of EIA standard RS-422

n Operation from single 5V supply

n TRI-STATE outputs for connection to system buses

n Low quiescent current

n Available in surface mount

Connection and Logic Diagrams

Truth Table

Input

Control

Non-Inverting

Inverting

Input

Output

Output

HH

H

L

LH

L

H

XL

Z

Z

L = Low logic state

H = High logic state

X = Irrelevant

Z = TRI-STATE (high performance)

Dual-In-Line Package

DS008576-1

Top View

Order Number DS34C87TM or DS34C87TN

See NS Package Number M16A or N16E

DS008576-2

May 1998

© 1998 National Semiconductor Corporation

DS008576

www.national.com