SN54F373, SN74F373
OCTAL TRANSPARENT D-TYPE LATCHES
WITH 3-STATE OUTPUTS
SDFS076A – D2932, MARCH 1987 – REVISED OCTOBER 1993
Copyright 1993, Texas Instruments Incorporated
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
•Eight Latches in a Single Package
•3-State Bus-Driving True Outputs
•Full Parallel Access for Loading
•Buffered Control Inputs
•Package Options Include Plastic
Small-Outline (SOIC) and Shrink
Small-Outline (SSOP) Packages, Ceramic
Chip Carriers, and Plastic and Ceramic
DIPs
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 ′F373 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
are latched at the logic levels 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) input 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 SN74F373 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 SN54F373 is characterized for operation over the full military temperature range of –55°C to 125°C. The
SN74F373 is characterized for operation from 0°C to 70°C.
FUNCTION TABLE
(each latch)
INPUTS OUTPUT
OE LE DQ
L H H H
LHL L
LLX 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
VCC
8Q
8D
7D
7Q
6Q
6D
5D
5Q
LE
SN54F373 ...J PACKAGE
SN74F373 ... DB, DW, OR N PACKAGE
(TOP VIEW)
3 2 1 20 19
9 10 11 12 13
4
5
6
7
8
18
17
16
15
14
2D
2Q
3Q
3D
4D
SN54F373 . . . FK PACKAGE
(TOP VIEW)
1D
1Q
OE
5Q
5D 8Q
4Q
GND
LE VCC
8D
7D
7Q
6Q
6D
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.