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.
SN54F373, SN74F373
OCTAL TRANSPARENT D-TYPE LATCHES
WITH 3-STATE OUTPUTS
SDFS076A – D2932, MARCH 1987 – REVISED OCTOBER 1993
2POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic symbol†logic diagram (positive logic)
OE
1D
3
1D 4
2D 7
3D 8
4D 13
5D
C1
11
LE
1Q
2
2Q
5
3Q
6
4Q
9
5Q
12
6Q
15
7Q
16
8Q
19
14
6D 17
7D 18
8D
EN
1OE
LE
1D 1Q
1
11
32
To Seven Other Channels
C1
1D
†This symbol is in accordance with ANSI/IEEE Std 91-1984
and IEC Publication 617-12.
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)‡
Supply voltage range, VCC –0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage range, VI (see Note 1) –1.2 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input current range –30 mA to 5 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage range applied to any output in the disabled or power-off state –0.5 V to 5.5 V. . . . . . . . . . . . . . . . . . .
Voltage range applied to any output in the high state –0.5 V to VCC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current into any output in the low state: SN54F373 40 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74F373 48 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range: SN54F373 –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74F373 0°C to 70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range –65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
‡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 af fect device reliability.
NOTE 1: The input voltage ratings may be exceeded provided the input current ratings are observed.
recommended operating conditions
SN54F373 SN74F373
UNIT
MIN NOM MAX MIN NOM MAX
UNIT
VCC Supply voltage 4.5 5 5.5 4.5 5 5.5 V
VIH High-level input voltage 2 2 V
VIL Low-level input voltage 0.8 0.8 V
IIK Input clamp current –18 –18 mA
IOH High-level output current –3 –3 mA
IOL Low-level output current 20 24 mA
TAOperating free-air temperature –55 125 0 70 °C
SN54F373, SN74F373
OCTAL TRANSPARENT D-TYPE LATCHES
WITH 3-STATE OUTPUTS
SDFS076A – D2932, MARCH 1987 – REVISED OCTOBER 1993
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
SN54F373 SN74F373
UNIT
PARAMETER
TEST
CONDITIONS
MIN TYP†MAX MIN TYP†MAX
UNIT
VIK VCC = 4.5 V, II = –18 mA –1.2 –1.2 V
VCC =45V
IOH = – 1 mA 2.5 3.4 2.5 3.4
VOH
V
CC =
4
.
5
V
IOH = – 3 mA 2.4 3.3 2.4 3.3 V
VCC = 4.75 V, IOH = – 1 mA to –3 mA 2.7
VOL
VCC =45V
IOL = 20 mA 0.3 0.5
V
V
OL
V
CC =
4
.
5
V
IOL = 24 mA 0.35 0.5
V
IOZH VCC = 5.5 V, VO = 2.7 V 50 50 µA
IOZL VCC = 5.5 V, VO = 0.5 V –50 –50 µA
IIVCC = 5.5 V, VI = 7 V 0.1 0.1 mA
IIH VCC = 5.5 V, VI = 2.7 V 20 20 µA
IIL VCC = 5.5 V, VI = 0.5 V – 0.6 – 0.6 mA
IOS‡VCC = 5.5 V, VO = 0 –60 –150 –60 –150 mA
ICCZ VCC = 5.5 V, See Note 2 38 55 38 55 mA
†All typical values are at VCC = 5 V, TA = 25°C.
‡Not more than one output should be shorted at a time, and the duration of the short circuit should not exceed one second.
NOTE 2: ICCZ is measured with OE at 4.5 V and all other inputs grounded.
timing requirements over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted)
VCC = 5 V,
TA = 25°CSN54F373 SN74F373
UNIT
′F373 UNIT
MIN MAX MIN MAX MIN MAX
twPulse duration, LE high 6 6 6 ns
tsu Setup time, data before LE↓2 2 2 ns
thHold time, data after LE↓3 3 3 ns
switching characteristics (see Note 3)
PARAMETER FROM
(
INPUT
)
TO
(
OUTPUT
)
VCC = 5 V,
CL = 50 pF,
RL = 500 Ω,
TA = 25°C
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
RL = 500Ω,
TA = MIN to MAX§UNIT
(INPUT)
(OUTPUT)
′F373 SN54F373 SN74F373
MIN TYP MAX MIN MAX MIN MAX
tPLH
D
Q
2.2 4.9 7 2.2 8.5 2.2 8
ns
tPHL
D
Q
1.2 3.3 5 1.2 7 1.2 6
ns
tPLH
LE
Q
4.2 8.6 11.5 4.2 15 4.2 13
ns
tPHL
LE
Q
2.2 4.8 7 2.2 8.5 2.2 8
ns
tPZH
OE
Q
1.2 4.6 11 1.2 13.5 1.2 12
ns
tPZL
OE
Q
1.2 5.2 7.5 1.2 10 1.2 8.5
ns
tPHZ
OE
Q
1.2 4.1 6.5 1.2 10 1.2 7.5
ns
tPLZ
OE
Q
1.2 3.4 6 1.2 7 1.2 6
ns
§For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
NOTE 3: Load circuits and waveforms are shown in Section 1.
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Copyright 1999, Texas Instruments Incorporated
