2000 Fairchild Semiconductor Corporation
DS010169
www.fairchildsemi.com
March 1989
Revised March 2000
DM74LS28 Quad 2-I
nput NOR
Buff
er
DM74LS28
Quad 2-Input NOR Buffer
General Description
The DM74LS28 contains four independent gates each of
which perform the logic NOR function.
Ordering Code:
Devices also available in Tape and Reel. Specify by appending the suffix letter "X" to the ordering code.
Connection Diagram
Truth Table
Y
=
A
+
B
H
=
HIGH logic level
L
=
LOW logic level
Order Number
Package Number
Package Description
DM74LS28M
M14A
14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-120, 0.150 Narrow
Inputs
Output
A
B
Y
L
L
H
L
H
L
H
L
L
H
H
L
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2
D
M
74LS28
Absolute Maximum Ratings
(Note 1)
Note 1: The "Absolute Maximum Ratings" are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The "Recommended Operating Conditions" table will define the conditions
for actual device operation.
Recommended Operating Conditions
Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Note 2: All typicals are at V
CC
=
5V, T
A
=
25
C.
Note 3: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Switching Characteristics
V
CC
=
+
5.0V, T
A
=
+
25
C
Supply Voltage
7V
Input Voltage
7V
Operating Free Air Temperature Range
0
C to
+
70
C
Storage Temperature Range
-
65
C to
+
150
C
Symbol
Parameter
Min
Nom
Max
Units
V
CC
Supply Voltage
4.75
5
5.25
V
V
IH
HIGH Level Input Voltage
2
V
V
IL
LOW Level Input Voltage
0.7
V
I
OH
HIGH Level Output Current
-
1.2
mA
I
OL
LOW Level Output Current
24
mA
T
A
Free Air Operating Temperature
0
70
C
Symbol
Parameter
Conditions
Min
Typ
Max
Units
(Note 2)
V
I
Input Clamp Voltage
V
CC
=
Min, I
I
=
-
18 mA
-
1.5
V
V
OH
HIGH Level Output Voltage
V
CC
=
Min, I
OH
=
Max, V
IL
=
Max
2.7
V
V
OL
LOW Level Output Voltage
V
CC
=
Min, I
OL
=
Max, V
IH
=
Min
0.5
V
I
OL
=
12 mA, V
CC
=
Min
0.4
I
I
Input Current @ Max Input Voltage
V
CC
=
Max, V
I
=
7V
0.1
mA
I
IH
HIGH Level Input Current
V
CC
=
Max, V
I
=
2.7V
20
A
I
IL
LOW Level Input Current
V
CC
=
Max, V
I
=
0.4V
-
0.4
mA
I
OS
Short Circuit Output Current
V
CC
=
Max (Note 3)
-
30
-
130
mA
I
CCH
Supply Current with Outputs HIGH
V
CC
=
Max
3.6
mA
I
CCL
Supply Current with Outputs LOW
V
CC
=
Max
13.8
mA
R
L
=
2 k
Symbol
Parameter
C
L
=
15 pF
Units
Min
Max
t
PLH
Propagation Delay Time
20
ns
LOW-to-HIGH Level Output
t
PHL
Propagation Delay Time
20
ns
HIGH-to-LOW Level Output
3
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DM74LS28 Quad 2-I
nput NOR
Buff
er
Physical Dimensions
inches (millimeters) unless otherwise noted
14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-120, 0.150 Narrow
Package Number M14A
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
LIFE SUPPORT POLICY
FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and (c) whose failure
to perform when properly used in accordance with
instructions for use provided in the labeling, can be rea-
sonably expected to result in a significant injury to the
user.
2. A critical component in any component of a life support
device or system whose failure to perform can be rea-
sonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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