SN54HC373, SN74HC373
OCTAL TRANSPARENT D-TYPE LATCHES
WITH 3-STATE OUTPUTS
SCLS140B – DECEMBER 1982 – REVISED MA Y 1997
D
Eight High-Current Latches in a Single
Package
D
High-Current 3-State True Outputs Can
Drive up to 15 LSTTL Loads
D
Full Parallel Access for Loading
D
Package Options Include Plastic
Small-Outline (DW), Shrink Small-Outline
(DB), Thin Shrink Small-Outline (PW), and
Ceramic Flat (W) Packages, Ceramic Chip
Carriers (FK), and Standard Plastic (N) and
Ceramic (J) 300-mil 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 ’HC373 are transparent
D-type latches. While the latch-enable (LE) input
is high, the Q outputs follow the data (D) inputs.
When LE is taken low, the Q outputs are latched
at the levels that were set up at the D inputs.
SN54HC373 ...J OR W PACKAGE
SN74HC373 . . . DB, DW, N, OR PW PACKAGE
SN54HC373 . . . FK PACKAGE
2D
2Q
3Q
3D
4D
(TOP VIEW)
OE
1
1Q
2
1D
3
2D
4
2Q
5
3Q
6
3D
7
4D
8
4Q
9
GND
10
(TOP VIEW)
1D1QOE
3212019
4
5
6
7
8
910111213
20
19
18
17
16
15
14
13
12
11
V
CC
V
8Q
8D
7D
7Q
6Q
6D
5D
5Q
LE
8Q
18
17
16
15
14
CC
8D
7D
7Q
6Q
6D
An output-enable (OE
outputs in either a normal logic state (high or low
) input places the eight
4Q
GND
LE
5Q
5D
logic levels) or the 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
interface or pullup components.
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 off.
The SN54HC373 is characterized for operation over the full military temperature range of –55°C to 125°C. The
SN74HC373 is characterized for operation from –40°C to 85°C.
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.
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.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Copyright 1997, Texas Instruments Incorporated
1
SN54HC373, SN74HC373
OCTAL TRANSPARENT D-TYPE LATCHES
WITH 3-STATE OUTPUTS
SCLS140B – DECEMBER 1982 – REVISED MA Y 1997
FUNCTION TABLE
INPUTS
OE LE D
L H H H
L HL L
L LX Q
H X X Z
(each latch)
OUTPUT
Q
0
logic symbol
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
†
OE
LE
1D
2D
3D
4D
5D
6D
7D
8D
1
11
3
4
7
8
13
14
17
18
EN
C1
1D
logic diagram (positive logic)
1
OE
11
LE
C1
1D
1D
3
12
15
16
19
2
1Q
5
2Q
6
3Q
9
4Q
5Q
6Q
7Q
8Q
2
1Q
To Seven Other Channels
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN54HC373, SN74HC373
OCTAL TRANSPARENT D-TYPE LATCHES
WITH 3-STATE OUTPUTS
SCLS140B – DECEMBER 1982 – REVISED MA Y 1997
absolute maximum ratings over operating free-air temperature range
Supply voltage range, V
–0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CC
†
Input clamp current, IIK (VI < 0 or VI > VCC) (see Note 1) ±20 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output clamp current, IOK (VO < 0 or VO > VCC) (see Note 1) ±20 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous output current, IO (VO = 0 to VCC) ±35 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous current through VCC or GND ±70 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Package thermal impedance, θ
(see Note 2): DB package 115°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
JA
DW package 97°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
N package 67°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PW package 128°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, T
†
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTES: 1. The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
2. The package thermal impedance is calculated in accordance with JESD 51, except for through-hole packages, which use a trace
length of zero.
–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stg
recommended operating conditions
SN54HC373 SN74HC373
MIN NOM MAX MIN NOM MAX
V
V
V
V
V
t
t
T
Supply voltage 2 5 6 2 5 6 V
CC
VCC = 2 V 1.5 1.5
High-level input voltage
IH
Low-level input voltage
IL
Input voltage 0 V
I
Output voltage 0 V
O
Input transition (rise and fall) time
Operating free-air temperature –55 125 –40 85 °C
A
VCC = 4.5 V
VCC = 6 V 4.2 4.2
VCC = 2 V 0 0.5 0 0.5
VCC = 4.5 V
VCC = 6 V 0 1.8 0 1.8
VCC = 2 V 0 1000 0 1000
VCC = 4.5 V
VCC = 6 V 0 400 0 400
3.15 3.15
0 1.35 0 1.35
CC
CC
0 500 0 500
0 V
0 V
CC
CC
V
V
V
V
ns
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
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