Absolute Maximum Ratings
(Note)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
Supply Voltage
7V
Input Voltage
7V
Operating Free Air Temperature Range
DM54LS and 54LS
DM74LS
b
55
§
C to
a
125
§
C
0
§
C to
a
70
§
C
b
65
§
C to
a
150
§
C
Storage Temperature Range
Note: The ‘‘Absolute Maximum Ratings’’ are those values
beyond which the safety of the device cannot be guaran-
teed. The device should not be operated at these limits. The
parametric values defined in the ‘‘Electrical Characteristics’’
table are not guaranteed at the absolute maximum ratings.
The ‘‘Recommended Operating Conditions’’ table will define
the conditions for actual device operation.
Recommended Operating Conditions
Symbol
Parameter
DM54LS257B
DM74LS257B
Units
Min
Nom
Max
Min
Nom
Max
V
CC
V
IH
V
IL
I
OH
I
OL
T
A
Supply Voltage
4.5
5
5.5
4.75
5
5.25
V
High Level Input Voltage
2
2
V
Low Level Input Voltage
0.7
0.8
V
High Level Output Current
b
1
b
2.6
mA
Low Level Output Current
12
24
mA
§
C
Free Air Operating Temperature
b
55
125
0
70
’LS257B Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
(Note 1)
V
I
V
OH
Input Clamp Voltage
V
CC
e
Min, I
I
e b
18 mA
V
CC
e
Min, I
OH
e
Max
V
IL
e
Max, V
IH
e
Min
b
1.5
V
High Level Output
Voltage
DM54
2.4
3.4
V
DM74
2.4
3.1
V
OL
Low Level Output
Voltage
V
CC
e
Min, I
OL
e
Max
V
IL
e
Max, V
IH
e
Min
DM54
0.25
0.4
DM74
0.35
0.5
V
I
OL
e
12 mA, V
CC
e
Min
V
CC
e
Max,
V
I
e
7V
DM74
0.25
0.4
I
I
Input Current
@
Max
Input Voltage
Select
0.2
mA
Other
0.1
I
IH
High Level Input
Current
V
CC
e
Max,
V
I
e
2.7V
Select
40
m
A
Other
20
I
IL
Low Level Input
Current
V
CC
e
Max,
V
I
e
0.4V
Select
b
0.8
b
0.4
mA
Other
I
OZH
Off-State Output Current
with High Level Output
Voltage Applied
V
CC
e
Max, V
O
e
2.7V
V
IH
e
Min, V
IL
e
Max
20
m
A
I
OZL
Off-State Output Current
with Low Level Output
Voltage Applied
V
CC
e
Max, V
O
e
0.4V
V
IH
e
Min, V
IL
e
Max
b
20
m
A
I
OS
Short Circuit
Output Current
V
CC
e
Max
(Note 2)
DM54
b
20
b
20
b
100
b
100
mA
DM74
I
CCH
Supply Current with
Outputs High
V
CC
e
Max (Note 3)
5.9
10
mA
I
CCL
Supply Current with
Outputs Low
V
CC
e
Max (Note 3)
9.2
16
mA
I
CCZ
Supply Current with
Outputs Disabled
V
CC
e
Max (Note 3)
12
19
mA
Note 1:
All typicals are at V
CC
e
5V, T
A
e
25
§
C.
Note 2:
Not more than one output should be shorted at a time, and the duration should not exceed one second.
Note 3:
I
CC
is measured with all outputs open and all possible inputs grounded, while achieving the stated output conditions.
2