54AC157
•
54ACT157 Quad 2-Input Multiplexer
July 1998
54AC157
•
54ACT157
Quad 2-Input Multiplexer
General Description
The ’AC/’ACT157 is a high-speed quad 2-input multiplexer.
Four bits of data from two sources can be selected using the
common Select and Enable inputs. The four outputs present
the selected data in the true (noninverted) form. The ’AC/
’ACT157 can also be used as a function generator.
Features
n
n
n
n
I
CC
and I
OZ
reduced by 50%
Outputs source/sink 24 mA
’ACT157 has TTL-compatible inputs
Standard Microcircuit Drawing (SMD)
— ’AC157: 5962-89539
— ’ACT157: 5962-89688
Logic Symbols
IEEE/IEC
DS100272-1
DS100272-2
Pin Names
I
0a
–I
0d
I
1a
–I
1d
E
S
Z
a
–Z
d
Description
Source 0 Data Inputs
Source 1 Data Inputs
Enable Input
Select Input
Outputs
Connection Diagrams
Pin Assignment
for DIP and Flatpak
Pin Assignment
for LCC
DS100272-3
DS100272-4
FACT
™
is a trademark of Fairchild Semiconductor Corporation.
© 1998 National Semiconductor Corporation
DS100272
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Functional Description
The ’AC/’ACT157 is a quad 2-input multiplexer. It selects
four bits of data from two sources under the control of a com-
mon Select input (S). The Enable input (E) is active-LOW.
When E is HIGH, all of the outputs (Z) are forced LOW re-
gardless of all other inputs. The ’AC/’ACT157 is the logic
implementation of a 4-pole, 2-position switch where the posi-
tion of the switch is determined by the logic levels supplied to
the Select input. The logic equations for the outputs are
shown below:
Z
a
= E
•
(I
1a
•
S + I
0a
•
S)
Z
b
= E
•
(I
1b
•
S + I
0b
•
S)
Z
c
= E
•
(I
1c
•
S + I
0c
•
S)
Z
d
= E
•
(I
1d
•
S + I
0d
•
S)
A common use of the ’AC/ACT157 is the moving of data from
two groups of registers to four common output busses. The
particular register from which the data comes is determined
by the state of the Select input. A less obvious use is as a
function generator. The ’AC/’ACT157 can generate any four
of the sixteen different functions of two variables with one
variable common. This is useful for implementing gating
functions.
Truth Table
Inputs
E
H
L
L
L
L
S
X
H
H
L
L
I
0
X
X
X
L
H
I
1
X
L
H
X
X
Outputs
Z
L
L
H
L
H
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
Logic Diagram
DS100272-5
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
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2
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V
CC
)
DC Input Diode Current (I
IK
)
V
I
= −0.5V
V
I
= V
CC
+ 0.5V
DC Input Voltage (V
I
)
DC Output Diode Current (I
OK
)
V
O
= −0.5V
V
O
= V
CC
+ 0.5V
DC Output Voltage (V
O
)
DC Output Source
or Sink Current (I
O
)
DC V
CC
or Ground Current
per Output Pin (I
CC
or I
GND
)
Storage Temperature (T
STG
)
Junction Temperature (T
J
)
CDIP
−0.5V to +7.0V
−20 mA
+20 mA
−0.5V to V
CC
+ 0.5V
−20 mA
+20 mA
−0.5V to V
CC
+ 0.5V
Recommended Operating
Conditions
Supply Voltage (V
CC
)
’AC
’ACT
Input Voltage (V
I
)
Output Voltage (V
O
)
Operating Temperature (T
A
)
54AC/ACT
Minimum Input Edge Rate (∆V/∆t)
’AC Devices
V
IN
from 30% to 70% of V
CC
V
CC
@
3.3V, 4.5V, 5.5V
Minimum Input Edge Rate (∆V/∆t)
’ACT Devices
V
IN
from 0.8V to 2.0V
V
CC
@
4.5V, 5.5V
2.0V to 6.0V
4.5V to 5.5V
0V to V
CC
0V to V
CC
−55˚C to +125˚C
125 mV/ns
±
50 mA
±
50 mA
−65˚C to +150˚C
175˚C
125 mV/ns
Note 1:
Absolute maximum ratings are those values beyond which damage
to the device may occur. The databook specifications should be met, without
exception, to ensure that the system design is reliable over its power supply,
temperature, and output/input loading variables. National does not recom-
mend operation of FACT
™
circuits outside databook specifications.
DC Characteristics for ’AC Family Devices
Symbol
Parameter
V
CC
(V)
V
IH
Minimum High Level
Input Voltage
V
IL
Maximum Low Level
Input Voltage
V
OH
Minimum High Level
Output Voltage
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
54AC
T
A
=
−55˚C to +125˚C
Guaranteed Limits
2.1
3.15
3.85
0.9
1.35
1.65
2.9
4.4
5.4
(Note 2)
V
IN
= V
IL
or V
IH
I
OH
= −12 mA
V
I
OH
= −24 mA
I
OH
= −24 mA
I
OUT
= 50 µA
V
I
OUT
= −50 µA
V
V
OUT
= 0.1V
or V
CC
− 0.1V
V
V
OUT
= 0.1V
or V
CC
− 0.1V
Units
Conditions
3.0
4.5
5.5
V
OL
Maximum Low Level
Output Voltage
3.0
4.5
5.5
2.4
3.7
4.7
0.1
0.1
0.1
V
3.0
4.5
5.5
I
IN
I
OLD
I
OHD
Maximum Input
Leakage Current
Minimum Dynamic
Output Current (Note 3)
5.5
5.5
5.5
0.50
0.50
0.50
V
µA
mA
mA
(Note 2)
V
IN
= V
IL
or V
IH
I
OL
= 12 mA
I
OL
= 24 mA
I
OL
= 24 mA
V
I
= V
CC
, GND
V
OLD
= 1.65V Max
V
OHD
= 3.85V Min
±
1.0
50
−50
3
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DC Characteristics for ’AC Family Devices
Symbol
Parameter
V
CC
(V)
I
CC
Maximum Quiescent
Supply Current
Note 2:
All outputs loaded; thresholds on input associated with output under test.
Note 3:
Maximum test duration 2.0 ms, one output loaded at a time.
(Continued)
54AC
T
A
=
−55˚C to +125˚C
Guaranteed Limits
80.0
Units
Conditions
5.5
µA
V
IN
= V
CC
or GND
Note 4:
I
IN
and I
CC
@
3.0V are guaranteed to be less than or equal to the respective limit
@
5.5V V
CC
.
I
CC
for 54AC
@
25˚C is identical to 74AC
@
25˚C.
DC Characteristics for ’ACT Family Devices
Symbol
Parameter
V
CC
(V)
V
IH
V
IL
V
OH
Minimum High Level
Input Voltage
Maximum Low Level
Input Voltage
Minimum High Level
Output Voltage
4.5
5.5
4.5
5.5
4.5
5.5
54ACT
T
A
=
−55˚C to +125˚C
Guaranteed Limits
2.0
2.0
0.8
0.8
4.4
5.4
(Note 5)
V
IN
= V
IL
or V
IH
I
OH
= −24 mA
I
OH
= −24 mA
I
OUT
= 50 µA
(Note 5)
V
IN
= V
IL
or V
IH
I
OL
= 24 mA
I
OL
= 24 mA
V
I
= V
CC
, GND
V
I
= V
CC
− 2.1V
V
OLD
= 1.65V Max
V
OHD
= 3.85V Min
V
IN
= V
CC
or GND
V
V
V
V
OUT
= 0.1V
or V
CC
− 0.1V
V
OUT
= 0.1V
or V
CC
− 0.1V
I
OUT
= −50 µA
Units
Conditions
4.5
5.5
V
OL
Maximum Low Level
Output Voltage
4.5
5.5
3.70
4.70
0.1
0.1
V
V
4.5
5.5
I
IN
I
CCT
I
OLD
I
OHD
I
CC
Maximum Input
Leakage Current
Maximum
I
CC
/Input
Minimum Dynamic
Output Current (Note 6)
Maximum Quiescent
Supply Current
Note 5:
All outputs loaded; thresholds on input associated with output under test.
Note 6:
Maximum test duration 2.0 ms, one output loaded at a time.
Note 7:
I
CC
for 54ACT
@
25˚C is identical to 74ACT
@
25˚C.
0.50
0.50
V
µA
mA
mA
mA
µA
5.5
5.5
5.5
5.5
5.5
±
1.0
1.6
50
−50
80.0
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4
AC Electrical Characteristics
V
CC
Symbol
Parameter
(V)
(Note 8)
Min
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
Propagation Delay
S to Z
n
Propagation Delay
S to Z
n
Propagation Delay
E to Z
n
Propagation Delay
E to Z
n
Propagation Delay
I
n
to Z
n
Propagation Delay
I
n
to Z
n
Note 8:
Voltage Range 3.3 is 3.3V
±
0.3V
Voltage Range 5.0 is 5.0V
±
0.5V
54AC
T
A
= −55˚C
to +125˚C
C
L
= 50 pF
Max
16.0
12.0
14.0
11.5
16.0
12.0
14.0
11.5
11.0
9.0
11.0
9.0
ns
ns
ns
ns
ns
ns
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
Units
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
AC Electrical Characteristics
V
CC
Symbol
Parameter
(V)
(Note 9)
Min
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
Propagation Delay
S to Z
n
Propagation Delay
S to Z
n
Propagation Delay
E to Z
n
Propagation Delay
E to Z
n
Propagation Delay
I
n
to Z
n
Propagation Delay
I
n
to Z
n
Note 9:
Voltage Range 5.0 is 5.0V
±
0.5V
54ACT
T
A
= −55˚C
to +125˚C
C
L
= 50 pF
Max
11.5
11.5
12.0
10.0
8.5
9.0
ns
ns
ns
ns
ns
ns
1.0
1.0
1.0
1.0
1.0
1.0
Units
5.0
5.0
5.0
5.0
5.0
5.0
Capacitance
Symbol
C
IN
C
PD
Parameter
Input Capacitance
Power Dissipation
Capacitance
Typ
4.5
50.0
Units
pF
pF
Conditions
V
CC
= OPEN
V
CC
= 5.0V
5
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