© 1999 Fairchild Semiconductor Corporation DS009958 www.fairchildsemi.com
November 1988
Revised November 1999
74AC373 • 74ACT373 Octal Transparent Latch with 3-STATE Outputs
74AC373 74ACT373
Octal Transparent Latch with 3-STATE Outputs
General Description
The AC/ACT373 consists of eight latches with 3-STATE
outputs for bus organized system applications. The flip-
flops appear transparent to the data when Latch Enable
(LE) is HIGH. When LE is LOW, the data that meets the
setup time is latched. Data appears on the bus when the
Output Enable (OE
) is LOW. When OE is HIGH, the bus
output is in the high impedance state.
Features
I
CC
and I
OZ
reduced by 50%
Eight latches in a single package
3-STATE outputs for bus interfacing
Outputs source/sink 24 mA
ACT373 has TTL-compatible inputs
Ordering Code:
Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering information
Logic Symbols
IEEE/IEC
Connection Diagram
Pin Descriptions
FACT is a trademark of Fairchild Semiconductor Corporation.
Order Number Package Number Package Description
74AC373SC M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide Body
74AC373SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74AC373MTC MTC20 20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74AC373PC N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
74ACT373SC M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide Body
74ACT373SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74ACT373MSA MSA20 20-Lead Shrink Small Outline Package (SSOP), EIAJ TYPE II, 5.3mm Wide
74ACT373MTC MTC20 20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74ACT373PC N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Pin Names Description
D
0
D
7
Data Inputs
LE Latch Enable Input
OE
Output Enable Input
O
0
O
7
3-STATE Latch Outputs
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74AC373 74ACT373
Functional Description
The AC/ACT373 contains eight D-type latches with 3-
STATE standard outputs. When the Latch Enable (LE)
input is HIGH, data on the D
n
inputs enters the latches. In
this condition the latches are transparent, i.e., a latch out-
put will change state each time its D-type input changes.
When LE is LOW, the latches store the information that
was present on the D-type inputs a setup time preceding
the HIGH-to-LOW transition of LE. The 3-STATE standard
outputs are controlled by the Output Enable (OE
) input.
When OE
is LOW, the standard outputs are in the 2-state
mode. When OE
is HIGH, the standard outputs are in the
high impedance mode but this does not interfere with
entering new data into the latches.
Truth Table
H = HIGH Voltage Level
L = LOW Voltage Level
Z = High Impedance
X = Immaterial
O
0
= Previous O
0
before HIGH-to-LOW transition of Latch Enable
Logic Diagram
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
Inputs Outputs
LE OE D
n
O
n
XHX Z
HLL L
HLH H
LLX O
0
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74AC373 74ACT373
Absolute Maximum Ratings(Note 1) Recommended Operating
Conditions
Note 1: Absolute maximum ratings are those values beyond which damage
to the device may occur. The databook specifications should be met, with-
out exception, to ensure that the system design is reliable over its power
supply, temperature, and output/input loading variables. Fairchild does not
recommend operation of FACT circuits outside databook specifications.
DC Electrical Characteristics for AC
Note 2: All outputs loaded, thresholds on input associated with output under test.
Note 3: Maximum test duration 2.0 ms, one output loaded at a time.
Note 4: I
IN
and I
CC
@ 3.0V are guaranteed to be less than or equal to the respective limit @ 5.5V V
CC
.
Supply Voltage (V
CC
) 0.5V to +7.0V
DC Input Diode Current (I
IK
)
V
I
= 0.5V 20 mA
V
I
= V
CC
+ 0.5V +20 mA
DC Input Voltage (V
I
) 0.5V to V
CC
+ 0.5V
DC Output Diode Current (I
OK
)
V
O
= 0.5V 20 mA
V
O
= V
CC
+ 0.5V +20 mA
DC Output Voltage (V
O
) 0.5V to V
CC
+ 0.5V
DC Output Source
or Sink Current (I
O
) ± 50 mA
DC V
CC
or Ground Current
per Output Pin (I
CC
or I
GND
) ± 50 mA
Storage Temperature (T
STG
) 65°C to +150°C
Junction Temperature (T
J
)
PDIP 140°C
Supply Voltage (V
CC
)
AC 2.0V to 6.0V
ACT 4.5V to 5.5V
Input Voltage (V
I
)0V to V
CC
Output Voltage (V
O
)0V to V
CC
Operating Temperature (T
A
) 40°C to +85°C
Minimum Input Edge Rate (V/t)
AC Devices
V
IN
from 30% to 70% of V
CC
V
CC
@ 3.3V, 4.5V, 5.5V 125 mV/ns
Minimum Input Edge Rate (V/t)
ACT Devices
V
IN
from 0.8V to 2.0V
V
CC
@ 4.5V, 5.5V 125 mV/ns
Symbol Parameter
V
CC
(V)
T
A
= +25°CT
A
= 40°C to +85°C
Units Conditions
Typ Guaranteed Limits
V
IH
Minimum HIGH Level 3.0 1.5 2.1 2.1 V
OUT
= 0.1V
Input Voltage 4.5 2.25 3.15 3.15 V or V
CC
0.1V
5.5 2.75 3.85 3.85
V
IL
Maximum LOW Level 3.0 1.5 0.9 0.9 V
OUT
= 0.1V
Input Voltage 4.5 2.25 1.35 1.35 V or V
CC
0.1V
5.5 2.75 1.65 1.65
V
OH
Minimum HIGH Level 3.0 2.99 2.9 2.9
Output Voltage 4.5 4.49 4.4 4.4 V I
OUT
= 50 µA
5.5 5.49 5.4 5.4
V
IN
= V
IL
or V
IH
3.0 2.56 2.46 I
OH
= 12 mA
4.5 3.86 3.76 V I
OH
= 24 mA
5.5 4.86 4.76 I
OL
= 24 mA (Note 2)
V
OL
Maximum LOW Level 3.0 0.002 0.1 0.1
Output Voltage 4.5 0.001 0.1 0.1 V I
OUT
= 50 µA
5.5 0.001 0.1 0.1
V
IN
= V
IL
or V
IH
3.0 0.36 0.44 I
OL
= 12 mA
4.5 0.36 0.44 V I
OL
= 24 mA
5.5 0.36 0.44 I
OL
= 24 mA (Note 2)
I
IN
(Note 4) Maximum Input Leakage Current 5.5 ± 0.1 ± 1.0 µAV
I
= V
CC
, GND
I
OZ
Maximum 3-STATE Current V
I
(OE) = V
IL
, V
IH
5.5 ±0.25 ± 2.5 µAV
I
= V
CC
, GND
V
O
= V
CC
, GND
I
OLD
Minimum Dynamic Output Current
(Note 3)
5.5 75 mA V
OLD
= 1.65V Max
I
OHD
5.5 75 mA V
OHD
= 3.85V Min
I
CC
(Note 4) Maximum Quiescent Supply Current 5.5 4.0 40.0 µAV
IN
= V
CC
or GND

74ACT373SCX

Mfr. #:
Manufacturer:
ON Semiconductor / Fairchild
Description:
Latches Octal Trans Latch
Lifecycle:
New from this manufacturer.
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