MC74AC373, MC74ACT373
Octal Transparent Latch
with 3−State Outputs
The MC74AC373/74ACT373 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
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•
•
•
•
•
Eight Latches in a Single Package
3−State Outputs for Bus Interfacing
Outputs Source/Sink 24 mA
′ACT373
Has TTL Compatible Inputs
Pb−Free Packages are Available
V
CC
20
O
7
19
D
7
18
D
6
17
O
6
16
O
5
15
D
5
14
D
4
13
O
4
12
LE
11
PDIP−20
N SUFFIX
CASE 738
1
SOIC−20W
DW SUFFIX
CASE 751D
1
TSSOP−20
DT SUFFIX
CASE 948E
1
OE
2
O
0
3
D
0
4
D
1
5
O
1
6
O
2
7
D
2
8
D
3
9
O
3
10
GND
SOEIAJ−20
M SUFFIX
CASE 967
1
1
Figure 1. Pinout: 20−Lead Packages Conductors
(Top View)
PIN ASSIGNMENT
PIN
D
0
−D
7
LE
OE
O
0
−O
7
FUNCTION
Data Inputs
Latch Enable Input
Output Enable Input
3−State Latch Outputs
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 8 of this data sheet.
DEVICE MARKING INFORMATION
See general marking information in the device marking
section on page 9 of this data sheet.
LE
OE
D
0
D
1
D
2
D
3
D
4
D
5
D
6
D
7
O
0
O
1
O
2
O
3
O
4
O
5
O
6
O
7
Figure 2. Logic Symbol
©
Semiconductor Components Industries, LLC, 2006
1
November, 2006 − Rev. 8
Publication Order Number:
MC74AC373/D
MC74AC373, MC74ACT373
TRUTH TABLE
Inputs
OE
H
L
L
L
LE
X
H
H
L
D
n
X
L
H
X
Outputs
O
n
Z
L
H
O
0
H = HIGH Voltage Level
L = LOW Voltage Level
Z = High Impedance
X = Immaterial
O
0
= Previous O
0
before LOW-to-HIGH Transition of Clock
FUNCTIONAL DESCRIPTION
The MC74AC373/74ACT373 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 output will change state each time its D input changes.
When LE is LOW, the latches store the information that was
present on the D 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.
D
3
D
4
D
5
D
6
D
7
D
0
D
1
D
2
D
G
LE
O
D
G
O
D
G
O
D
G
O
D
G
O
D
G
O
D
G
O
D
G
O
OE
NOTE:
This diagram is provided only for the understanding of logic operations and
should not be used to estimate propagation delays.
Figure 3. Logic Diagram
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2
MC74AC373, MC74ACT373
MAXIMUM RATINGS
Symbol
V
CC
V
IN
V
OUT
I
IN
I
OUT
I
CC
T
stg
Parameter
DC Supply Voltage (Referenced to GND)
DC Input Voltage (Referenced to GND)
DC Output Voltage (Referenced to GND)
DC Input Current, per Pin
DC Output Sink/Source Current, per Pin
DC V
CC
or GND Current per Output Pin
Storage Temperature
Value
−0.5 to +7.0
−0.5 to V
CC
+0.5
−0.5 to V
CC
+0.5
±20
±50
±50
−65 to +150
Unit
V
V
V
mA
mA
mA
°C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
RECOMMENDED OPERATING CONDITIONS
Symbol
V
CC
V
IN
, V
OUT
Supply Voltage
DC Input Voltage, Output Voltage (Ref. to GND)
V
CC
@ 3.0 V
t
r
, t
f
Input Rise and Fall Time (Note 1)
′AC
Devices except Schmitt Inputs
Input Rise and Fall Time (Note 2)
′ACT
Devices except Schmitt Inputs
Junction Temperature (PDIP)
Operating Ambient Temperature Range
Output Current − High
Output Current − Low
V
CC
@ 4.5 V
V
CC
@ 5.5 V
t
r
, t
f
T
J
T
A
I
OH
I
OL
V
CC
@ 4.5 V
V
CC
@ 5.5 V
Parameter
′AC
′ACT
Min
2.0
4.5
0
−
−
−
−
−
−
−40
−
−
Typ
5.0
5.0
−
150
40
25
10
8.0
−
25
−
−
Max
6.0
5.5
V
CC
−
−
−
−
ns/V
−
140
85
−24
24
°C
°C
mA
mA
ns/V
V
V
Unit
1. V
IN
from 30% to 70% V
CC
; see individual Data Sheets for devices that differ from the typical input rise and fall times.
2. V
IN
from 0.8 V to 2.0 V; see individual Data Sheets for devices that differ from the typical input rise and fall times.
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3
MC74AC373, MC74ACT373
DC CHARACTERISTICS
74AC
Symbol
Parameter
V
CC
(V)
T
A
= +25°C
Typ
V
IH
Minimum High Level
Input Voltage
Maximum Low Level
Input Voltage
Minimum High Level
Output Voltage
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
V
OL
Maximum Low Level
Output Voltage
3.0
4.5
5.5
3.0
4.5
5.5
I
IN
I
OZ
Maximum Input
Leakage Current
Maximum
3−State
Current
†Minimum Dynamic
Output Current
5.5
1.5
2.25
2.75
1.5
2.25
2.75
2.99
4.49
5.49
−
−
−
0.002
0.001
0.001
−
−
−
−
74AC
T
A
=
−40°C to +85°C
Unit
Conditions
Guaranteed Limits
2.1
3.15
3.85
0.9
1.35
1.65
2.9
4.4
5.4
2.56
3.86
4.86
0.1
0.1
0.1
0.36
0.36
0.36
±0.1
2.1
3.15
3.85
0.9
1.35
1.65
2.9
4.4
5.4
2.46
3.76
4.76
0.1
0.1
0.1
0.44
0.44
0.44
±1.0
V
V
OUT
= 0.1 V
or V
CC
− 0.1 V
V
OUT
= 0.1 V
or V
CC
− 0.1 V
I
OUT
= −50
mA
V
*V
IN
= V
IL
or V
IH
−12 mA
I
OH
−24 mA
−24 mA
I
OUT
= 50
mA
V
*V
IN
= V
IL
or V
IH
12 mA
I
OL
24 mA
24 mA
V
I
= V
CC
, GND
V
I
(OE) = V
IL
, V
IH
V
I
= V
CC
, GND
V
O
= V
CC
, GND
V
OLD
= 1.65 V
Max
V
OHD
= 3.85 V Min
V
IN
= V
CC
or GND
V
IL
V
V
OH
V
V
mA
5.5
−
±0.5
−
−
8.0
±5.0
75
−75
80
mA
mA
mA
mA
I
OLD
I
OHD
I
CC
5.5
5.5
−
−
−
Maximum Quiescent
Supply Current
5.5
*All outputs loaded; thresholds on input associated with output under test.
†Maximum test duration 2.0 ms, one output loaded at a time.
NOTE: I
IN
and I
CC
@ 3.0 V are guaranteed to be less than or equal to the respective limit @ 5.5 V V
CC
.
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4
MC74AC373, MC74ACT373
AC CHARACTERISTICS
(For Figures and Waveforms − See AND8277/D at www.onsemi.com)
74AC
Symbol
Parameter
V
CC
*
(V)
Min
t
PLH
t
PHL
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
Propagation Delay
D
n
to O
n
Propagation Delay
D
n
to O
n
Propagation Delay
LE to O
n
Propagation Delay
LE to O
n
Output Enable Time
Output Enable Time
Output Disable Time
Output Disable Time
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
T
A
= +25°C
C
L
= 50 pF
Typ
10
7.0
9.5
7.0
10
7.5
9.5
7.0
9.0
7.0
8.5
6.5
10
8.0
8.0
6.5
Max
13.5
9.5
13
9.5
13.5
9.5
12.5
9.5
11.5
8.5
11.5
8.5
12.5
11
11.5
8.5
74AC
T
A
= −40°C
to +85°C
C
L
= 50 pF
Min
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
Max
15
10.5
14.5
10.5
15
10.5
14
10.5
13
9.5
13
9.5
14.5
12.5
12.5
10
ns
ns
ns
ns
ns
ns
ns
ns
3−5
3−5
3−6
3−6
3−7
3−8
3−7
3−8
Unit
Fig.
No.
*Voltage Range 3.3 V is 3.3 V
±0.3
V.
Voltage Range 5.0 V is 5.0 V
±0.5
V.
AC OPERATING REQUIREMENTS
74AC
Symbol
Parameter
V
CC
*
(V)
T
A
= +25°C
C
L
= 50 pF
Typ
t
s
t
h
t
w
Setup Time, HIGH or LOW
D
n
to LE
Hold Time, HIGH or LOW
D
n
to LE
LE Pulse Width, HIGH
3.3
5.0
3.3
5.0
3.3
5.0
3.5
2.0
−3.0
−1.5
4.0
2.0
74AC
T
A
= −40°C
to +85°C
C
L
= 50 pF
Unit
Fig.
No.
Guaranteed Minimum
5.5
4.0
1.0
1.0
5.5
4.0
6.0
4.5
1.0
1.0
6.0
4.5
ns
ns
ns
3−9
3−9
3−6
*Voltage Range 3.3 V is 3.3 V
±0.3
V.
Voltage Range 5.0 V is 5.0 V
±0.5
V.
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