ST34C87

QUAD RS-422 CMOS

Differential Line Driver

Rev. 1.01

E1991

EXAR Corporation, 48720 Kato Road, Fremont, CA 94538

z (510) 668-7000 z FAX (510) 668-7017

1

June 1997-3

FEATURES

D Pin-to-Pin Compatible with National DS34C87

D Low Power CMOS Design

D Three-State Outputs with Enable Pin

D Meets the EIA RS-422 Requirements

D Low Propagation Delays

D High Speed

GENERAL DESCRIPTION

The ST34C87 is a CMOS quad differential line driver

designed to meet the standard RS-422 requirements and

digital data transmission over balanced lines. To improve

noise margin and output stability for slow changing input

signals, special hysteresis is built in the ST34C87 circuit.

The ST34C87 is a high speed CMOS line driver designed

to operate with MFM / RLL controllers and hard disk

drives as well as RS-422

digital data transmission

applications. ST34C87 is suitable for low power 5V

operation with high input voltage protection devices.

ORDERING INFORMATION

Part No.

Package

Operating

Temperature Range

ST34C87CP16

16 Lead 300 Mil PDIP

0

°C to +70°C

ST34C87CF16

16 Lead 150 Mil JEDEC SOIC

0

°C to +70°C

ST34C87IP16

16 Lead 300 Mil PDIP

-40

°C to +85°C

ST34C87IF16

16 Lead 150 Mil JEDEC SOIC

-40

°C to +85°C

Figure 1. Block Diagram

INPUT A

OUTPUTA+

OUTPUT A-

ENABLE A/B

OUTPUTB-

OUTPUTB+

INPUT B

INPUT D

OUTPUT D+

OUTPUT D-

OUTPUT C-

OUTPUT C+

INPUT C

ENABLE C/D