TECHNICAL DATA
1
Octal 3-State Noninverting Buffer/Line
Driver/Line Receiver
These octal buffers and line drivers and designed specifically to
improve both the performance and density of three-state memory
address drivers, clock drivers, and busoriented receivers and
transmitters.
This devise features high fan-out, improved fan-in, and 400 mV
noise margin.
It can be used to drive terminated lines down to 133 ohms.
3-State Outputs Drive Bus Lines or Buffer Memory Address
Registers
P-N-P Inputs Reduce D-C Loading
Hysteresis at Inputs Improves Noise Margins
IN74LS244
ORDERING INFORMATION
IN74LS244N Plastic
IN74LS244DW SOIC
T
A
= 0
to 70
C
for all packages
FUNCTION TABLE
Inputs
Outputs
Enable A,
Enable B
A,B
YA,YB
L
L
L
L
H
H
H
X
Z
X=don't care
Z = high impedance
LOGIC DIAGRAM
PIN 20=V
CC
PIN 10 = GND
PIN ASSIGNMENT
IN74LS244
2
MAXIMUM RATINGS
*
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
7.0
V
V
IN
Input Voltage
7.0
V
V
OUT
Output Voltage
5.5
V
Tstg
Storage Temperature Range
-65 to +150
C
*
Maximum Ratings are those values beyond which damage to the device may occur.
Functional operation should be restricted to the Recommended Operating Conditions.
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Min
Max
Unit
V
CC
Supply Voltage
4.75
5.25
V
V
IH
High Level Input Voltage
2.0
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
Ambient Temperature Range
0
+70
C
DC ELECTRICAL CHARACTERISTICS over full operating conditions
Guaranteed Limit
Symbol
Parameter
Test Conditions
Min
Max
Unit
V
IK
Input Clamp Voltage
V
CC
= min, I
IN
= -18 mA
-1.5
V
V
OH
High Level Output Voltage
V
CC
= min, I
OH
= -1.0 mA
2.7
V
V
CC
= min, I
OH
= -3.0 mA
2.4
V
CC
= min, I
OH
= -15 mA
2.0
V
OL
Low Level Output Voltage
V
CC
= min, I
OL
= 12 mA
0.4
V
V
CC
= min, I
OL
= 24 mA
0.5
V
T+
- V
T-
Hysteresis
V
CC
= min
0.2
V
I
OZH
Output Off Current HIGH
V
CC
= max, V
OUT
= 2.7 V
20
A
I
OZL
Output Off Current LOW
V
CC
= max, V
OUT
= 0.4 V
-20
A
I
IH
High Level Input Current
V
CC
= max, V
IN
= 2.7 V
20
A
V
CC
= max, V
IN
= 7.0 V
0.1
mA
I
IL
Low Level Input Current
V
CC
= max, V
IN
= 0.4 V
-0.2
mA
I
O
Output Short Circuit Current
V
CC
= max, V
O
=0 V
(Note 1)
-40
-225
mA
I
CC
Supply
Outputs High
V
CC
= max
27
mA
Current
Outputs Low
Outputs open
46
All outputs
disabled
54
note 1: Not more than one output should be shorted at a time, and duration of the short-circuit should not exceed
one second
IN74LS244
3
IN74LS244
4
AC ELECTRICAL CHARACTERISTICS
(T
A
= 25
C, V
CC
= 5.0 V, t
r
= 15 ns,
t
f
= 6.0 ns)
Symbol
Parameter
Test Condition
Min
Max
Unit
t
PLH
Propagation Delay, Data to
Output
18
ns
t
PHL
Propagation Delay, Data to
Output
C
L
= 45 pF,
R
L
= 667
18
ns
t
PZH
Output Enable Time
23
ns
t
PZL
Output Enable Time
30
ns
t
PHZ
Output Disable Time
C
L
= 5 pF
18
ns
t
PLZ
Output Disable Time
R
L
= 667
25
ns
t
PZL
- S1 closed, S2 opened
t
PZH
- S1 opened, S2 closed
t
PLZ
, t
PHZ
- S1 and S2 closed
Figure 1. Switching Waveforms
(See Figure 3)
Figure 2. Switching Waveforms
(See Figure 4)
NOTES A. C
L
includes probe and jig capacitance.
B. All diodes are 1N916 or 1N3064.
NOTES A. C
L
includes probe and jig capacitance.
B. All diodes are 1N916 or 1N3064.
Figure 3. Test Circuit
Figure 4. Test Circuit
IN74LS244
5
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