Page 1
August 1989
54LS244/DM74LS244 Octal TRI-STATE Buffers/Line Drivers/Line Receivers
54LS244/DM74LS244 Octal TRI-STATE
Buffers/Line Drivers/Line Receivers
Y
General Description
These buffers/line drivers are designed to improve both the
performance and PC board density of TRI-STATE buffers/
drivers employed as memory-address drivers, clock drivers,
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 outputs
and can be used to drive terminated lines down to 133X.
Features
Y
TRI-STATE outputs drive bus lines directly
Y
PNP inputs reduce DC loading on bus lines
Y
Hysteresis at data inputs improves noise margins
Connection Diagram
Dual-In-Line Package
Typical IOL(sink current)
54LS 12 mA
74LS 24 mA
Y
Typical IOH(source current)
Y
Typical propagation delay times
54LS
74LS
b
b
Inverting 10.5 ns
Noninverting 12 ns
Y
Typical enable/disable time 18 ns
Y
Typical power dissipation (enabled)
Inverting 130 mW
Noninverting 135 mW
É
12 mA
15 mA
Order Number 54LS244DMQB, 54LS244FMQB, 54LS244LMQB,
TL/F/8442– 1
DM74LS244WM or DM74LS244N
See NS Package Number E20A, J20A, M20B, N20A or W20A
Function Table
Inputs Output
G AY
LL L
LH H
HX Z
e
L
Low Logic Level
e
H
High Logic Level
e
X
Either Low or High Logic Level
e
Z
High Impedance
TRI-STATEÉis a registered trademark of National Semiconductor Corporation.
C
1995 National Semiconductor Corporation RRD-B30M105/Printed in U. S. A.
TL/F/8442
Page 2
Absolute Maximum Ratings (Note)
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
54LS
DM74LS 0
Storage Temperature Range
b
55§Ctoa125§C
Ctoa70§C
§
b
65§Ctoa150§C
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’’
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
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
Low Level Output Current 12 24 mA
Free Air Operating Temperature
54LS244 DM74LS244
Min Nom Max Min Nom Max
b
12
b
55 125 0 70
b
15 mA
Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted)
2
0.5
50
40
Typ
(Note 1)
Max Units
b
1.5 V
20 mA
b
20 mA
0.1 mA
b
200 mA
b
225 mA
Symbol Parameter Conditions Min
e
V
I
Input Clamp Voltage V
HYS Hysteresis (V
Data Inputs Only
V
V
I
OZH
I
OZL
I
I
I
IH
I
IL
I
OS
I
CC
OH
OL
High Level Output Voltage V
Low Level Output Voltage V
Off-State Output Current, V
High Level Voltage Applied V
Off-State Output Current,
Low Level Voltage Applied
Input Current at Maximum V
Input Voltage V
High Level Input Current V
Low Level Input Current V
Short Circuit Output Current V
Supply Current V
CC
b
V
a
T
)V
b
T
CC
CC
e
V
IL
V
CC
e
V
IL
V
CC
e
V
IL
CC
e
V
IL
e
V
IH
CC
e
IL
e
V
IH
CC
CC
CC
CC
CC
Outputs Open
eb
Min, I
e
Min
e
Min, V
Max, I
e
Min, V
Max, I
e
Min, V
0.5V, I
e
Min I
Max V
Min
e
Max V
Max
Min
e
Max V
e
Max V
e
Max V
e
Max (Note 2)
e
Max, Outputs High 13 23
18 mA
I
e
Min DM74
IH
eb
1mA
OH
e
Min 54LS/DM74
IH
eb
3mA
OH
e
Min 54LS/DM74
IH
e
Max
OH
e
12 mA 54LS/DM74 0.4
OL
e
I
Max DM74 0.5
OL
e
2.7V
O
e
V
0.4V
O
e
7V (DM74)
I
e
10V (54LS)
I
e
2.7V 20 mA
I
e
0.4V
I
54LS
DM74
0.2 0.4 V
2.7
2.4 3.4 V
b
b
b
Outputs Low 27 46 mA
Outputs Disabled 32 54
e
Note 1: All typicals are at V
Note 2: Not more than one output should be shorted at a time, and the duration should not exceed one second.
CC
5V, T
e
25§C.
A
Units
C
§
2
Page 3
Switching Characteristics at V
CC
e
5V, T
e
25§C (see Section 1 for Test Waveforms and Output Load)
A
Symbol Parameter Conditions 54LS Max DM74LS Max Units
and t
PZH
e
45 pF
L
e
667X
L
e
45 pF
L
e
667X
L
e
45 pF
L
e
667X
L
e
45 pF
L
e
667X
L
e
5pF
L
e
667X
L
e
5pF
L
e
667X
L
e
150 pF
L
e
667X
L
e
150 pF
L
e
667X
L
e
150 pF
L
e
667X
L
e
150 pF
L
e
667X
L
.
18 18 ns
18 18 ns
30 30 ns
23 23 ns
25 25 ns
18 18 ns
21 ns
22 ns
33 ns
26 ns
t
PLH
t
PHL
t
PZL
t
PZH
t
PLZ
t
PHZ
t
PLH
t
PHL
t
PZL
t
PZH
Note: 54LS Output Load is C
Propagation Delay Time C
Low to High Level Output R
Propagation Delay Time C
High to Low Level Output R
Output Enable Time to C
Low Level R
Output Enable Time to C
High Level R
Output Disable Time C
from Low Level R
Output Disable Time C
from High Level R
Propagation Delay Time C
Low to High Level Output R
Propagation Delay Time C
High to Low Level Output R
Output Enable Time to C
Low Level R
Output Enable Time to C
High Level R
e
L
50 pF for t
PLH,tPHL,tPZL
3
Page 4
Physical Dimensions inches (millimeters)
Ceramic Leadless Chip Carrier Package (E)
Order Number 54LS244LMQB
NS Package Number E20A
20-Lead Ceramic Dual-In-Line Package (J)
Order Number 54LS244DMQB
NS Package Number J20A
4
Page 5
Physical Dimensions inches (millimeters) (Continued)
20-Lead Wide Small Outline Molded Package (M)
Order Number DM74LS244WM
NS Package Number M20B
20-Lead Molded Dual-In-Line Package (N)
Order Number DM74LS244N
NS Package Number N20A
5
Page 6
Physical Dimensions inches (millimeters) (Continued)
20-Lead Ceramic Flat Package (W)
Order Number 54LS244FMQB
NS Package Number W20A
LIFE SUPPORT POLICY
NATIONAL’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 NATIONAL
SEMICONDUCTOR CORPORATION. As used herein:
54LS244/DM74LS244 Octal TRI-STATE Buffers/Line Drivers/Line Receivers
1. Life support devices or systems are devices or 2. A critical component is any component of a life
systems which, (a) are intended for surgical implant support device or system whose failure to perform can
into the body, or (b) support or sustain life, and whose be reasonably expected to cause the failure of the life
failure to perform, when properly used in accordance support device or system, or to affect its safety or
with instructions for use provided in the labeling, can effectiveness.
be reasonably expected to result in a significant injury
to the user.
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