54F 74F251A 8-Input Multiplexer with TRI-STATE Outputs
November 1994
54F 74F251A
8-Input Multiplexer with TRI-STATE Outputs
General Description
The ’F251A is a high-speed 8-input digital multiplexer It pro-
vides in one package the ability to select one bit of data
from up to eight sources It can be used as a universal func-
tion generator to generate any logic function of four vari-
ables Both assertion and negation outputs are provided
Features
Y
Y
Y
Multifunctional capability
On-chip select logic decoding
Inverting and non-inverting TRI-STATE outputs
74F251APC
54F251ADM (Note 2)
74F251ASC (Note 1)
74F251ASJ (Note 1)
54F251AFM (Note 2)
54F251ALL (Note 2)
N16E
J16A
M16A
16-Lead (0 300 Wide) Molded Dual-In-Line
16-Lead Ceramic Dual-In-Line
M16D
W16A
E20A
Note 1
Devices also available in 13 reel Use suffix
e
SCX and SJX
Note 2
Military grade device with environmental and burn-in processing Use suffix
e
DMQB FMQB and LMQB
Logic Symbols
O
TL F 9504–5
TRI-STATE is a registered trademark of National Semiconductor Corporation
C
1995 National Semiconductor Corporation
TL F 9504
bs
ol
Pin Assignment for
DIP SOIC and Flatpak
TL F 9504–3
IEEE IEC
et
16-Lead Cerpack
20-Lead Ceramic Leadless Chip Carrier Type C
16-Lead (0 150 Wide) Molded Small Outline JEDEC
16-Lead (0 300 Wide) Molded Small Outline EIAJ
Connection Diagrams
Pin Assignment
for LCC
TL F 9504 – 1
TL F 9504 – 2
e
RRD-B30M75 Printed in U S A
Commercial
Military
Package
Number
Package Description
Unit Loading Fan Out
54F 74F
Pin Names
Description
UL
HIGH LOW
10 10
10 10
10 10
150 40 (33 3)
150 40 (33 3)
Input I
IH
I
IL
Output I
OH
I
OL
20
mA
b
0 6 mA
20
mA
b
0 6 mA
20
mA
b
0 6 mA
b
3 mA 24 mA (20 mA)
b
3 mA 24 mA (20 mA)
S
0
– S
2
OE
I
0
– I
7
Z
Z
Select Inputs
TRI-STATE Output Enable Input (Active LOW)
Multiplexer Inputs
TRI-STATE Multiplexer Output
Complementary TRI-STATE Multiplexer Output
Functional Description
This device is a logical implementation of a single-pole 8-
position switch with the switch position controlled by the
state of three Select inputs S
0
S
1
S
2
Both assertion and
negation outputs are provided The Output Enable input
(OE) is active LOW When it is activated the logic function
provided at the output is
Z
e
OE
(I
0
S
0
S
1
S
2
a
I
1
S
0
S
1
S
2
a
I
2
S
0
S
1
S
2
a
I
3
S
0
S
1
S
2
a
I
4
S
0
S
1
S
2
a
I
5
S
0
S
1
S
2
a
I
6
S
0
S
1
S
2
a
I
7
S
0
S
1
S
2
)
When the Output Enable is HIGH both outputs are in the
high impedance (High Z) state This feature allows multi-
plexer expansion by tying the outputs of up to 128 devices
together When the outputs of the TRI-STATE devices are
tied together all but one device must be in the high imped-
ance state to avoid high currents that would exceed the
maximum ratings The Output Enable signals should be de-
signed to ensure there is no overlap in the active LOW por-
tion of the enable voltages
Truth Table
Inputs
OE
H
L
L
L
L
L
L
L
L
S
2
X
L
L
L
S
1
X
L
L
H
S
0
X
L
H
L
H
L
H
L
H
Outputs
Z
Z
I
0
I
1
I
2
I
3
I
4
I
5
I
6
I
7
Z
Z
I
0
I
1
I
2
I
3
I
4
I
5
I
6
I
7
Logic Diagram
O
TL F 9504 – 4
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays
bs
ol
2
et
H
e
HIGH Voltage Level
L
e
LOW Voltage Level
X
e
Immaterial
Z
e
High Impedance
L
H
H
H
H
e
H
L
L
H
H
Absolute Maximum Ratings
(Note 1)
If Military Aerospace specified devices are required
please contact the National Semiconductor Sales
Office Distributors for availability and specifications
Storage Temperature
Ambient Temperature under Bias
Junction Temperature under Bias
Plastic
V
CC
Pin Potential to
Ground Pin
Input Voltage (Note 2)
Input Current (Note 2)
Voltage Applied to Output
in HIGH State (with V
CC
e
0V)
Standard Output
TRI-STATE Output
b
65 C to
a
150 C
b
55 C to
a
125 C
b
55 C to
a
175 C
b
55 C to
a
150 C
b
0 5V to
a
7 0V
b
0 5V to
a
7 0V
b
30 mA to
a
5 0 mA
Current Applied to Output
in LOW State (Max)
twice the rated I
OL
(mA)
Note 1
Absolute maximum ratings are values beyond which the device may
be damaged or have its useful life impaired Functional operation under
these conditions is not implied
Note 2
Either voltage limit or current limit is sufficient to protect inputs
Recommended Operating
Conditions
Free Air Ambient Temperature
Military
Commercial
Supply Voltage
Military
Commercial
b
55 C to
a
125 C
0 C to
a
70 C
a
4 5V to
a
5 5V
a
4 5V to
a
5 5V
b
0 5V to V
CC
b
0 5V to
a
5 5V
DC Electrical Characteristics
Symbol
V
IH
V
IL
V
CD
V
OH
Parameter
Min
Input HIGH Voltage
Input LOW Voltage
Input Clamp Diode Voltage
Output HIGH
Voltage
54F 10% V
CC
54F 10% V
CC
74F 10% V
CC
74F 10% V
CC
74F 5% V
CC
74F 5% V
CC
54F 10% V
CC
74F 10% V
CC
20
Typ
Max
08
V
OL
I
IH
I
BVI
I
CEX
V
ID
I
OD
I
IL
bs
ol
Output LOW
Voltage
05
05
V
Min
Input HIGH
Current
54F
74F
20 0
50
100
70
mA
mA
mA
V
Max
Max
Max
00
Input HIGH Current
Breakdown Test
Output HIGH
Leakage Current
54F
74F
54F
74F
74F
74F
250
50
Input Leakage
Test
4 75
Output Leakage
Circuit Current
3 75
mA
00
Input LOW Current
b
0 6
O
I
OZH
I
OZL
I
OS
I
ZZ
Output Leakage Current
Output Leakage Current
Bus Drainage Test
I
CCL
I
CCZ
Power Supply Current
Power Supply Current
Output Short-Circuit Current
et
b
1 2
25
24
25
24
27
27
50
b
50
b
60
b
150
500
15
16
22
24
3
e
Units
V
V
V
CC
Conditions
V
Min
I
IN
e b
18 mA
I
OH
I
OH
I
OH
I
OH
I
OH
I
OH
e
e
e
e
e
e
b
1 mA
b
3 mA
b
1 mA
b
3 mA
b
1 mA
b
3 mA
54F 74F
Recognized as a HIGH Signal
Recognized as a LOW Signal
V
Min
I
OL
e
20 mA
I
OL
e
24 mA
V
IN
e
2 7V
V
IN
e
7 0V
V
OUT
e
V
CC
I
ID
e
1 9
mA
All Other Pins Grounded
V
IOD
e
150 mV
All Other Pins Grounded
V
IN
e
0 5V
V
OUT
e
2 7V
V
OUT
e
0 5V
V
OUT
e
0V
V
OUT
e
5 25V
V
O
e
LOW
V
O
e
HIGH Z
mA
mA
mA
mA
mA
mA
mA
Max
Max
Max
Max
0 0V
Max
Max
AC Electrical Characteristics
74F
Symbol
Parameter
Min
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
t
PZH
t
PZL
t
PHZ
t
PLZ
Propagation Delay
S
n
to Z
Propagation Delay
S
n
to Z
Propagation Delay
I
n
to Z
Propagation Delay
I
n
to Z
Output Enable Time
OE to Z
Output Disable Time
OE to Z
Output Enable Time
OE to Z
Output Disable Time
OE to Z
35
32
45
40
30
15
35
35
25
25
25
15
35
35
20
15
T
A
e a
25 C
V
CC
e a
5 0V
C
L
e
50 pF
Typ
60
50
75
60
50
25
50
55
43
43
40
30
50
55
38
30
Max
90
75
10 5
85
65
40
70
70
60
60
55
45
70
75
55
45
54F
T
A
V
CC
e
Mil
C
L
e
50 pF
Min
35
32
35
30
25
15
25
35
20
25
25
15
30
35
20
15
Max
11 5
80
14 0
10 5
80
60
90
90
70
75
60
50
85
90
55
55
74F
T
A
V
CC
e
Com
C
L
e
50 pF
Min
35
32
45
40
30
15
25
35
25
25
25
15
30
35
20
15
Max
95
75
12 5
90
70
50
80
75
70
65
60
45
75
80
55
45
ns
ns
ns
ns
Units
O
4
bs
ol
et
e
ns
ns
Ordering Information
The device number is used to form part of a simplified purchasing code where the package type and temperature range are
defined as follows
74F
Temperature Range Family
74F
e
Commercial
54F
e
Military
Device Type
Package Code
P
e
Plastic DIP
D
e
Ceramic DIP
F
e
Flatpak
L
e
Leadless Chip Carrier (LCC)
S
e
Small Outline SOIC JEDEC
SJ
e
Small Outline SOIC EIAJ
251A
S
C
X
Special Variations
QB
e
Military grade device with
environmental and burn-in
processing
X
e
Devices shipped in 13 reel
Temperature Range
C
e
Commercial (0 C to
a
70 C)
M
e
Military (
b
55 C to
a
125 C)
O
bs
ol
20-Lead Ceramic Leadless Chip Carrier (L)
NS Package Number E20A
5
et
e
Physical Dimensions
inches (millimeters)
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