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SN54HCT623, SN74HCT623
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCLS016B – MARCH 1984 – REVISED MAY 1997
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
D Inputs Are TTL-Voltage Compatible
D Lock Bus-Latch Capability
D True Logic
D High-Current 3-State Outputs Can Drive up
to 15 LSTTL Loads
D Package Options Include Plastic
Small-Outline (DW) and Ceramic Flat (W)
Packages, Ceramic Chip Carriers (FK), and
Standard Plastic (N) and Ceramic (J)
300-mil DIPs
description
These octal bus transceivers are designed for
asynchronous two-way communication between
data buses. The control-function implementation
allows for maximum flexibility in timing.
The ’HCT623 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 (OEAB and OEBA) inputs.
The output-enable inputs disable the device so
that the buses are effectively isolated. The
dual-enable configuration gives the transceivers
the capability to store data by simultaneously
enabling
OEAB
and
OEBA.
Each
output
reinforces
its
input
in
this
transceiver
configuration. When both OEAB and OEBA are
enabled and all other data sources to the two sets
of bus lines are in the high-impedance state, both
sets of bus lines (16 total) remain at their last
states. The 8-bit codes appearing on the two sets
of buses are identical.
The SN54HCT623 is characterized for operation over the full military temperature range of –55
°C to 125°C. The
SN74HCT623 is characterized for operation from –40
°C to 85°C.
FUNCTION TABLE
INPUTS
OPERATION
OEBA
OEAB
OPERATION
L
B data to A bus
H
A data to B bus
H
L
Isolation
L
H
B data to A bus,
A data to B bus
Copyright
1997, Texas Instruments Incorporated
UNLESS OTHERWISE NOTED this document contains PRODUCTION
DATA information 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.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
SN54HCT623 ...J OR W PACKAGE
SN74HCT623 . . . DW OR N PACKAGE
(TOP VIEW)
SN54HCT623 . . . FK PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
OEAB
A1
A2
A3
A4
A5
A6
A7
A8
GND
VCC
OEBA
B1
B2
B3
B4
B5
B6
B7
B8
32 1 20 19
910 11 1213
4
5
6
7
8
18
17
16
15
14
B1
B2
B3
B4
B5
A3
A4
A5
A6
A7
A2
A1
OEAB
B7
B6
V
OEBA
A8
GND
B8
CC