2000 Fairchild Semiconductor Corporation
DS008442
www.fairchildsemi.com
August 1986
Revised March 2000
DM74LS244
Octa
l 3-ST
A
T
E
Buf
f
er
/Li
ne D
r
ive
r
/L
ine Recei
ver
DM74LS244
Octal 3-STATE Buffer/Line Driver/Line Receiver
General Description
These buffers/line drivers are designed to improve both the
performance and PC board density of 3-STATE buffers/
drivers employed as memory-address drivers, clock driv-
ers, and bus-oriented transmitters/receivers. Featuring 400
mV of hysteresis at each low current PNP data line input,
they provide improved noise rejection and high fanout out-
puts and can be used to drive terminated lines down to
133
.
Features
s
3-STATE outputs drive bus lines directly
s
PNP inputs reduce DC loading on bus lines
s
Hysteresis at data inputs improves noise margins
s
Typical I
OL
(sink current)
24 mA
s
Typical I
OH
(source current)
-
15 mA
s
Typical propagation delay times
Inverting
10.5 ns
Noninverting
12 ns
s
Typical enable/disable time
18 ns
s
Typical power dissipation (enabled)
Inverting
130 mW
Noninverting
135 mW
Ordering Code:
Devices also available in Tape and Reel. Specify by appending the suffix letter "X" to the ordering code.
Connection Diagram
Function Table
L
=
LOW Logic Level
H
=
HIGH Logic Level
X
=
Either LOW or HIGH Logic Level
Z
=
High Impedance
Order Number
Package Number
Package Description
DM74LS244WM
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74LS244SJ
M20D
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74LS244N
N20A
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Inputs
Output
G
A
Y
L
L
L
L
H
H
H
X
Z
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2
DM74LS244
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.
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
0.8
V
I
OH
HIGH Level Output Current
-
15
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
HYS
Hysteresis (V
T
+
-
V
T
-
)
V
CC
=
Min
0.2
0.4
V
Data Inputs Only
V
OH
HIGH Level Output Voltage
V
CC
=
Min, V
IH
=
Min
2.7
V
IL
=
Max, I
OH
=
-
1 mA
V
CC
=
Min, V
IH
=
Min
2.4
3.4
V
V
IL
=
Max, I
OH
=
-
3 mA
V
CC
=
Min, V
IH
=
Min
2
V
IL
=
0.5V, I
OH
=
Max
V
OL
LOW Level Output Voltage
V
CC
=
Min
I
OL
=
12 mA
0.4
V
V
IL
=
Max
I
OL
=
Max
0.5
V
IH
=
Min
I
OZH
Off-State Output Current,
V
CC
=
Max
V
O
=
2.7V
20
A
HIGH Level Voltage Applied
V
IL
=
Max
I
OZL
Off-State Output Current,
V
IH
=
Min
V
O
=
0.4V
-
20
A
LOW Level Voltage Applied
I
I
Input Current at Maximum
V
CC
=
Max
V
I
=
7V
0.1
mA
Input Voltage
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
-
0.5
-
200
A
I
OS
Short Circuit Output Current
V
CC
=
Max (Note 3)
-
40
-
225
mA
I
CC
Supply Current
V
CC
=
Max,
Outputs HIGH
13
23
Outputs Open
Outputs LOW
27
46
mA
Outputs Disabled
32
54
3
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DM74LS244
Switching Characteristics
at V
CC
=
5V, T
A
=
25
C
Symbol
Parameter
Conditions
Max
Units
t
PLH
Propagation Delay Time
C
L
=
45 pF
18
ns
LOW-to-HIGH Level Output
R
L
=
667
t
PHL
Propagation Delay Time
C
L
=
45 pF
18
ns
HIGH-to-LOW Level Output
R
L
=
667
t
PZL
Output Enable Time to
C
L
=
45 pF
30
ns
LOW Level
R
L
=
667
t
PZH
Output Enable Time to
C
L
=
45 pF
23
ns
HIGH Level
R
L
=
667
t
PLZ
Output Disable Time
C
L
=
5 pF
25
ns
from LOW Level
R
L
=
667
t
PHZ
Output Disable Time
C
L
=
5 pF
18
ns
from HIGH Level
R
L
=
667
t
PLH
Propagation Delay Time
C
L
=
150 pF
21
ns
LOW-to-HIGH Level Output
R
L
=
667
t
PHL
Propagation Delay Time
C
L
=
150 pF
22
ns
HIGH-to-LOW Level Output
R
L
=
667
t
PZL
Output Enable Time to
C
L
=
150 pF
33
ns
LOW Level
R
L
=
667
t
PZH
Output Enable Time to
C
L
=
150 pF
26
ns
HIGH Level
R
L
=
667
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4
DM74LS244
Physical Dimensions
inches (millimeters) unless otherwise noted
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
Package Number M20B
5
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DM74LS244
Physical Dimensions
inches (millimeters) unless otherwise noted (Continued)
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
Package Number M20D
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