SN54BCT544, SN74BCT544
OCTAL REGISTERED TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCBS039B – NOVEMBER 1988 – REVISED NOVEMBER 1993
SN54BCT544 . . . JT OR W PACKAGE
SN74BCT544 . . . DW OR NT PACKAGE
(TOP VIEW)
• State-of-the-Art BiCMOS Design
Significantly Reduces I
CCZ
• ESD Protection Exceeds 2000 V
Per MIL-STD-883C, Method 3015
LEBA
OEBA
A1
1
2
3
4
5
6
7
8
9
10
24
V
CC
• Power-Up High-Impedance State
• 3-State Inverting Outputs
• Back-to-Back Registers for Storage
23 CEBA
22 B1
21 B2
20 B3
19 B4
18 B5
17 B6
16 B7
A2
A3
A4
A5
A6
A7
A8
• Package Options Include Plastic
Small-Outline (DW) Packages, Ceramic
Chip Carriers (FK) and Flatpacks (W), and
Plastic and Ceramic 300-mil DIPs (JT, NT)
15
B8
description
CEAB 11
GND 12
14 LEAB
13 OEAB
The ′BCT544 octal registered transceiver
contains two sets of D-type latches for temporary
storage of data flowing in either direction.
Separate latch-enable (LEAB or LEBA) and
output-enable (OEAB or OEBA) inputs are
provided for each register to permit independent
control in either direction of data flow.
SN54BCT544 . . . FK PACKAGE
(TOP VIEW)
The A-to-B enable (CEAB) input must be low in
order to enter data from A or to output data from
B. If CEAB is low and LEAB is low, the A-to-B
latches are transparent; a subsequent low-to-high
transitionofLEABputstheAlatchesinthestorage
mode. With CEAB and OEAB both low, the 3-state
B outputs are active and reflect the inverted data
present at the output of the A latches. Data flow
from B to A is similar, but requires using the CEBA,
LEBA, and OEBA inputs.
4
3
2
1
28 27 26
25
5
6
7
8
9
A2
A3
A4
NC
A5
A6
A7
B2
B3
B4
24
23
22 NC
21 B5
20 B6
19 B7
10
11
12 13 14 15 16 17 18
The SN54BCT544 is characterized for operation
over the full military temperature range of –55°C
to 125°C. The SN74BCT544 is characterized for
operation from 0°C to 70°C.
NC – No internal connection
†
FUNCTION TABLE
INPUTS
OUTPUT
B
CEAB
LEAB
OEAB
A
X
X
X
L
H
L
L
L
L
X
X
H
L
X
H
L
Z
Z
‡
B
0
L
H
L
L
L
H
†
‡
A-to-B data flow is shown; B-to-A flow control is the same
except that it uses CEBA, LEBA, and OEBA.
Output level before the indicated steady-state input
conditions were established.
Copyright 1993, Texas Instruments Incorporated
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.
1
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