TL F 6388
DM74LS126A
Quad
TRI-STATE
Buffer
September 1991
DM74LS126A Quad TRI-STATE
Buffer
General Description
This device contains four independent gates each of which
performs a non-inverting buffer function The outputs have
the TRI-STATE feature When enabled the outputs exhibit
the low impedance characteristics of a standard LS output
with additional drive capability to permit the driving of bus
lines without external resistors When disabled both the
output transistors are turned off presenting a high-imped-
ance state to the bus line Thus the output will act neither as
a significant load nor as a driver To minimize the possibility
that two outputs will attempt to take a common bus to oppo-
site logic levels the disable time is shorter than the enable
time of the outputs
Connection Diagram
Dual-In-Line Package
TL F 6388 1
Order Number DM74LS126AM or DM74LS126AN
See NS Package Number M14A or N14A
Function Table
Y
e
A
Inputs
Output
A
C
Y
L
H
L
H
H
H
X
L
Hi-Z
H
e
High Logic Level
L
e
Low Logic Level
X
e
Either Low or High Logic Level
Hi-Z
e
TRI-STATE (Outputs are disabled)
TRI-STATE
is a registered trademark of National Semiconductor Corporation
C1995 National Semiconductor Corporation
RRD-B30M105 Printed in U S A
Absolute Maximum Ratings
(Note)
Supply Voltage
7V
Input Voltage
7V
Operating Free Air Temperature Range
0 C to
a
70 C
Storage Temperature Range
b
65 C to
a
150 C
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
Min
Nom
Max
Units
V
CC
Supply Voltage
4 75
5
5 25
V
V
IH
High Level Input Voltage
V
V
IL
Low Level Input Voltage
0 8
V
I
OH
High Level Output Current
b
2 6
mA
I
OL
Low Level Output Current
24
mA
T
A
Free Air Operating Temperature
0
70
C
Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
(Note 1)
V
I
Input Clamp Voltage
V
CC
e
Min I
I
e b
18 mA
b
1 5
V
V
OH
High Level Output
V
CC
e
Min I
OH
e
Max
2 4
V
Voltage
V
IH
e
Min
V
OL
Low Level Output
V
CC
e
Min I
OL
e
Max
0 35
0 5
Voltage
V
IL
e
Max V
IH
e
Min
V
I
OL
e
12 mA V
CC
e
Min
0 25
0 4
I
I
Input Current
Max
V
CC
e
Max V
I
e
7V
0 1
mA
Input Voltage
I
IH
High Level Input Current
V
CC
e
Max V
I
e
2 7V
20
m
A
I
IL
Low Level Input
V
CC
e
Max V
I
e
0 4V
b
0 4
mA
Current
I
OZH
Off-State Output Current
V
CC
e
Max V
O
e
2 4V
with High Level Output
V
IH
e
Min V
IL
e
Max
20
m
A
Voltage Applied
I
OZL
Off-State Output Current
V
CC
e
Max V
O
e
0 4V
with Low Level Output
V
IH
e
Min V
IL
e
Max
b
20
m
A
Voltage Applied
I
OS
Short Circuit
V
CC
e
Max
b
20
b
100
mA
Output Current
(Note 2)
I
CC
Supply Current
V
CC
e
Max
12
22
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
2
Switching Characteristics
DM74LS
R
L
e
667X
Symbol
Parameter
C
L
e
50 pF
C
L
e
150 pF
Units
Min
Max
Min
Max
t
PLH
Propagation Delay Time Low
15
21
ns
to High Level Output
t
PHL
Propagation Delay Time High
18
22
ns
to Low Level Output
t
PZH
Output Enable Time to
30
36
ns
High Level Output
t
PZL
Output Enable Time to
30
42
ns
Low Level Output
t
PHZ
Output Disable Time from
25
ns
High Level Output (Note 1)
t
PLZ
Output Disable Time from
25
ns
Low Level Output (Note 1)
Note 1
C
L
e
5pF
Physical Dimensions
inches (millimeters)
14-Lead Small Outline Molded Package (M)
Order Number DM74LS126AM
NS Package Number M14A
3
DM74LS126A
Quad
TRI-STATE
Buffer
Physical Dimensions
inches (millimeters) (Continued)
14-Lead Molded Dual-In-Line Package (N)
Order Number DM74LS126AN
NS Package Number N14A
LIFE SUPPORT POLICY
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DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL
SEMICONDUCTOR CORPORATION As used herein
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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