DS96177 RS-485/RS-422 Differential Bus Repeater
October 1993
DS96177
RS-485/RS-422 Differential Bus Repeater
General Description
The DS96177 Differential Bus Repeater is a monolithic inte-
grated device designed for one-way data communication on
multipoint bus transmission lines. This device is designed for
balanced transmission bus line applications and meets EIA
Standard RS-485 and RS-422A. The device is designed to
improve the performance of the data communication over
long bus lines. The DS96177 has an active high Enable.
The DS96177 features positive and negative current limiting
and TRI-STATE
廬
outputs for the receiver and driver. The re-
ceiver features high input impedance, input hysteresis for in-
creased noise immunity, and input sensitivity of 200 mV over
a common mode input voltage range of 鈭?2V to +12V. The
driver features thermal shutdown for protection from line
fault conditions. Thermal shutdown is designed to occur at a
junction temperature of approximately 160藲C. The driver is
designed to drive current loads up to 60 mA maximum.
The DS96177 is designed for optimum performance when
used on transmission buses employing the DS96172 and
DS96174 differential line drivers, DS96173 and DS96175
differential line receivers, or DS96176 differential bus trans-
ceivers.
Features
n
Meets EIA Standard RS-422A and RS-485
n
Designed for multipoint transmission on long bus lines in
noisy environments
n
TRI-STATE outputs
n
Bus voltage range 鈭?.0V to +12V
n
Positive and negative current limiting
n
Driver output capability
鹵
60 mA max
n
Driver thermal shutdown protection
n
Receiver input high impedance
n
Receiver input sensitivity of
鹵
200 mV
n
Receiver input hysteresis of 50 mV typical
n
Operates from single 5.0V supply
n
Low power requirements
Connection Diagram
8-Lead Dual-In-Line Package
Function Table
Differential Inputs
A鈥揃
V
ID
鈮?/div>
0.2V
V
ID
鈮?/div>
鈭?.2V
X
Enable
E
H
H
L
T
H
L
Z
Outputs
Y
H
L
Z
Z
L
H
Z
DS009644-1
Note:
T is an output pin only, monitoring the BUS (RO).
H = High Level
L = Low Level
X = Immaterial
Z = High Impedance (off)
Top View
Order Number DS96177CN
See NS Package Number N08E
TRI-STATE
廬
is a registered trademark of National Semiconductor Corporation.
漏 1999 National Semiconductor Corporation
DS009644
www.national.com
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