SN54ALS243A, SN74ALS243A
QUADRUPLE BUS TRANSCEIVERS
WITH 3STATE OUTPUTS
SDAS069B DECEMBER 1982 REVISED DECEMBER 1994
Copyright
1994, Texas Instruments Incorporated
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
POST OFFICE BOX 1443
HOUSTON, TEXAS 772511443
Two-Way Asynchronous Communication
Between Data Buses
pnp Inputs Reduce dc Loading
Package Options Include Plastic
Small-Outline (D) Packages, Ceramic Chip
Carriers (FK), and Standard Plastic (N) and
Ceramic (J) 300-mil DIPs
description
These quadruple bus transceivers are designed
for
asynchronous
two-way
communication
between
data
buses.
The
control-function
implementation allows for maximum flexibility in
timing. These devices allow data transmission
from the A bus to the B bus or from the B bus to the
A bus depending upon the logic levels at the
output-enable (OEBA and OEAB) inputs. The
output-enable inputs can be used to disable the
device so that the buses are effectively isolated.
The
dual-enable
configuration
gives
the
quadruple bus transceivers the capability to store
data by simultaneously enabling OEBA and
OEAB. Each output reinforces its input in this
transceiver configuration. When both control
inputs are enabled and all other data sources to
the two sets of bus lines are at high impedance,
both sets of bus lines (eight in all) retain their
states. The 4-bit codes appearing on the two sets
of buses are identical.
The SN54ALS243A is characterized for operation over the full military temperature range of 55
°C to 125°C.
The SN74ALS243A is characterized for operation from 0
°C to 70°C.
FUNCTION TABLE
INPUTS
FUNCTION
OEAB
OEBA
FUNCTION
L
A to B
H
B to A
H
L
Isolation
L
H
Latch A and B
(A = B)
SN54ALS243A ...J PACKAGE
SN74ALS243A ...D OR N PACKAGE
(TOP VIEW)
SN54ALS243A . . . FK PACKAGE
(TOP VIEW)
32
1 20 19
910 11 12 13
4
5
6
7
8
18
17
16
15
14
NC
B1
NC
B2
A1
NC
A2
NC
A3
NC
OEAB
NC
B4
B3
V
OEBA
A4
GND
NC
CC
NC No internal connection
1
2
3
4
5
6
7
14
13
12
11
10
9
8
OEAB
NC
A1
A2
A3
A4
GND
VCC
OEBA
NC
B1
B2
B3
B4
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.