DM74LS244N [NSC]
Octal TRI-STATEE Buffers/Line Drivers/Line Receivers; 八TRI- STATEE缓冲器/线路驱动器/线接收器
| 型号： | DM74LS244N |
| 厂家： | 
National Semiconductor |
| 描述： | Octal TRI-STATEE Buffers/Line Drivers/Line Receivers |
| 文件： | 总6页 (文件大小：142K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
August 1989
54LS244/DM74LS244 Octal TRI-STATE
Buffers/Line Drivers/Line Receivers
É
Y
Typical I (sink current)
OL
General Description
54LS
74LS
12 mA
24 mA
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.
Y
Y
Typical I
54LS
74LS
(source current)
OH
b
b
12 mA
15 mA
Typical propagation delay times
Inverting 10.5 ns
Noninverting 12 ns
Y
Y
Typical enable/disable time 18 ns
Typical power dissipation (enabled)
Inverting 130 mW
Noninverting 135 mW
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
TL/F/8442–1
Order Number 54LS244DMQB, 54LS244FMQB, 54LS244LMQB,
DM74LS244WM or DM74LS244N
See NS Package Number E20A, J20A, M20B, N20A or W20A
Function Table
Inputs
Output
Y
G
A
L
L
L
H
X
L
H
Z
H
e
e
e
e
L
Low Logic Level
High Logic Level
H
X
Z
Either Low or High Logic Level
High Impedance
TRI-STATEÉ is a registered trademark of National Semiconductor Corporation.
C
1995 National Semiconductor Corporation
TL/F/8442
RRD-B30M105/Printed in U. S. A.
Absolute Maximum Ratings (Note)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
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.
Supply Voltage
Input Voltage
7V
7V
Operating Free Air Temperature Range
54LS
b
b
a
55 C to 125 C
§
0 C to 70 C
§
a
DM74LS
Storage Temperature Range
§
§
§
a
65 C to 150 C
§
Recommended Operating Conditions
54LS244
DM74LS244
Symbol
Parameter
Units
Min
4.5
2
Nom
Max
Min
4.75
2
Nom
Max
V
V
V
Supply Voltage
5
5.5
5
5.25
V
V
CC
High Level Input Voltage
Low Level Input Voltage
High Level Output Current
Low Level Output Current
Free Air Operating Temperature
IH
0.7
0.8
V
IL
b
b
I
I
12
12
125
15
24
70
mA
mA
OH
OL
b
T
A
55
0
C
§
Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted)
Typ
Symbol
Parameter
Conditions
Min
Max
Units
(Note 1)
e
e
e b
I
b
1.5
V
Input Clamp Voltage
V
V
Min, I
18 mA
V
V
I
CC
b
HYS
Hysteresis (V
a
Data Inputs Only
V
)
b
T
Min
T
CC
0.2
2.7
2.4
2
0.4
e
e
V
OH
High Level Output Voltage
V
V
Min, V
Min
DM74
CC
IH
e
e b
Max, I
1 mA
3 mA
IL
OH
e
e
V
V
Min, V
Min
54LS/DM74
54LS/DM74
CC
IH
3.4
V
e
e b
Max, I
IL
OH
e
e
e
V
V
Min, V
Min
CC
IH
e
0.5V, I
Max
IL
OH
e
e
e
e
V
OL
Low Level Output Voltage
V
V
V
Min
Max
Min
I
I
12 mA
Max
54LS/DM74
DM74
0.4
CC
OL
V
IL
e
0.5
OL
IH
e
e
I
I
I
Off-State Output Current,
High Level Voltage Applied
V
V
V
Max
V
2.7V
0.4V
OZH
OZL
I
CC
O
O
20
mA
mA
mA
e
e
Max
IL
Min
IH
e
Off-State Output Current,
Low Level Voltage Applied
V
b
20
e
e
Input Current at Maximum
Input Voltage
V
CC
Max
V
V
7V (DM74)
10V (54LS)
I
0.1
20
e
e
e
I
e
e
I
I
High Level Input Current
Low Level Input Current
V
V
Max
Max
V
2.7V
0.4V
mA
mA
IH
IL
CC
I
I
b
b
V
0.5
200
225
CC
b
54LS
50
40
e
b
I
I
Short Circuit Output Current
Supply Current
V
CC
Max (Note 2)
mA
OS
CC
b
DM74
e
Outputs Open
V
CC
Max,
Outputs High
Outputs Low
Outputs Disabled
13
27
32
23
46
54
mA
e
e
25 C.
Note 1: All typicals are at V
5V, T
§
Note 2: Not more than one output should be shorted at a time, and the duration should not exceed one second.
CC
A
2
e
e
25 C (see Section 1 for Test Waveforms and Output Load)
Switching Characteristics at V
5V, T
§
CC
A
Symbol
Parameter
Conditions
54LS Max
DM74LS Max
Units
e
e
t
t
t
t
t
t
t
t
t
t
Propagation Delay Time
Low to High Level Output
C
45 pF
PLH
PHL
PZL
PZH
PLZ
PHZ
PLH
PHL
PZL
PZH
L
18
18
ns
R
667X
L
e
e
Propagation Delay Time
High to Low Level Output
C
L
45 pF
18
30
23
25
18
18
30
23
25
18
21
22
33
26
ns
ns
ns
ns
ns
ns
ns
ns
ns
R
667X
L
e
e
Output Enable Time to
Low Level
C
L
45 pF
R
667X
L
e
e
Output Enable Time to
High Level
C
L
45 pF
R
667X
L
e
e
Output Disable Time
from Low Level
C
L
5 pF
R
667X
L
e
e
Output Disable Time
from High Level
C
L
5 pF
R
667X
L
e
e
Propagation Delay Time
Low to High Level Output
C
L
150 pF
R
667X
L
e
e
Propagation Delay Time
High to Low Level Output
C
L
150 pF
R
667X
L
e
e
Output Enable Time to
Low Level
C
L
150 pF
R
667X
L
e
e
Output Enable Time to
High Level
C
L
150 pF
R
667X
L
e
Note: 54LS Output Load is C
50 pF for t
, t
, t
PLH PHL PZL
and t
.
PZH
L
3
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
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
Physical Dimensions inches (millimeters) (Continued)
20-Lead Ceramic Flat Package (W)
Order Number 54LS244FMQB
NS Package Number W20A
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