SN54HCT623, SN74HCT623
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCLS016B – MARCH 1984 – REVISED MAY 1997
SN54HCT623 . . . J OR W PACKAGE
SN74HCT623 . . . DW OR N PACKAGE
(TOP VIEW)
Inputs Are TTL-Voltage Compatible
Lock Bus-Latch Capability
True Logic
OEAB
A1
V
CC
OEBA
High-Current 3-State Outputs Can Drive up
to 15 LSTTL Loads
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
A2
A3
A4
A5
A6
A7
A8
GND
B1
B2
B3
B4
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
B5
13 B6
12 B7
description
11
B8
These octal bus transceivers are designed for
asynchronous two-way communication between
data buses. The control-function implementation
allows for maximum flexibility in timing.
SN54HCT623 . . . FK PACKAGE
(TOP VIEW)
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.
3
2
1
20 19
18
B1
B2
B3
A3
A4
A5
A6
A7
4
5
6
7
8
17
16
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.
15 B4
14
9 10 11 12 13
B5
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
L
H
H
L
H
L
B data to A bus
A data to B bus
Isolation
B data to A bus,
A data to B bus
L
H
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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.
1
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