SN54BCT373, SN74BCT373
OCTAL TRANSPARENT D-TYPE LATCHES
WITH 3-STATE OUTPUTS
SCBS016C – SEPTEMBER 1988 – REVISED NOVEMBER 1993
Copyright 1993, Texas Instruments Incorporated
2–1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
• State-of-the-Art BiCMOS Design
Significantly Reduces Standby Current
• Full Parallel Access for Loading
• 3-State True Outputs Drive Bus Lines
or Buffer Memory Address Registers
• ESD Protection Exceeds 2000 V
Per MIL-Std-883C, Method 3015
• Package Options Include Plastic
Small-Outline (DW) and Shrink
Small-Outline (DB) Packages, Ceramic Chip
Carriers (FK) and Flatpacks (W), and
Standard Plastic and Ceramic 300-mil DIPs
(J, N)
description
These 8-bit latches feature 3-state outputs
designed specifically for driving highly capacitive
or relatively low-impedance loads. They are
particularly suitable for implementing buffer
registers, I/O ports, bidirectional bus drivers, and
working registers.
The eight latches of the ′BCT373 are transparent
D-type latches. While the latch-enable (LE) input
is high, the Q outputs will follow the data (D) inputs.
When the latch enable is taken low, the Q outputs
will be latched at the logic levels that were set up
at the D inputs.
A buffered output-enable (OE
) input can be used to place the eight outputs in either a normal logic state (high
or low logic levels) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive
the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus
lines without need for interface or pullup components.
The output enable (OE) does not affect the internal operations of the latches. Old data can be retained or new
data can be entered while the outputs are in the high-impedance state.
The SN74BCT373 is available in TI’s shrink small-outline package (DB), which provides the same I/O pin count
and functionality of standard small-outline packages in less than half the printed-circuit-board area.
The SN54BCT373 is characterized for operation over the full military temperature range of –55°C to 125°C. The
SN74BCT373 is characterized for operation from 0°C to 70°C.
FUNCTION TABLE
(each latch)
INPUTS
OUTPUT
OE LE D
Q
L H H H
L HL L
L LX Q
0
H X X Z
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
OE
1Q
1D
2D
2Q
3Q
3D
4D
4Q
GND
V
CC
8Q
8D
7D
7Q
6Q
6D
5D
5Q
LE
SN54BCT373 ...J OR W PACKAGE
SN74BCT373 . . . DB, DW, OR N PACKAGE
(TOP VIEW)
3 2 1 20 19
910111213
4
5
6
7
8
18
17
16
15
14
8D
7D
7Q
6Q
6D
2D
2Q
3Q
3D
4D
1D1QOE
5Q
5D
8Q
4Q
GND
LE
V
CC
SN54BCT373 . . . FK PACKAGE
(TOP VIEW)
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.