DS36276 Datasheet, PDF (1/12 Pages) National Semiconductor (TI) – FAILSAFE Multipoint Transceiver

July 1998
DS36276
FAILSAFE Multipoint Transceiver
General Description
The DS36276 FAILSAFE Multipoint Transceiver is designed
for use on bi-directional differential busses. It is compatible
with existing TIA/EIA-485 transceivers, however, it offers an
additional feature not supported by standard transceivers.
The FAILSAFE feature guarantees the receiver output to a
known state when the Interface is in the following conditions:
Floating Line, Idle Line (no active drivers), and Line Fault
conditions (open or short). The receiver output is in a HIGH
state for the following conditions: OPEN Inputs, Terminated
Inputs (50Ω), and SHORTED Inputs.
FAILSAFE is a highly desirable feature when the transceiv-
ers are used with Asynchronous Controllers such as UARTs.
Features
n FAILSAFE receiver, RO = HIGH for:
— OPEN inputs
— Terminated inputs
— SHORTED inputs
n Compatible with popular interface standards:
— TIA/EIA-485 (RS-485)
— TIA/EIA-422-A (RS-422-A)
— CCITT Recommendation V.11
n Bi-Directional Transceiver
— Designed for multipoint transmission
n Separate driver input, driver enable, receiver enable,
and receiver output for maximum flexibility
n Wide bus common mode range
— (−7V to +12V)
n Pin compatible with: DS75176B, DS96176, DS3695 and
SN75176A and B
n Available in SOIC package
Connection and
Logic Diagram
Truth Tables
Driver
Inputs
RE
DE
DI
X
H
H
X
H
L
X
L
X
Outputs
DO/RI
DO /RI
H
L
L
H
Z
Z
DS011383-1
Order Number DS36276M
See NS Package Number M08A
Receiver
Inputs
RE
DE
L
L
L
L
H
X
RI–RI
≥0V
≤−500 mV
X
Output
RO
H
L
Z
Receiver FAILSAFE
Inputs
RE
DE
RI–RI
L
L
SHORTED
L
L
OPEN
H
X
X
Output
RO
H
H
Z
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© 1999 National Semiconductor Corporation DS011383
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