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
I
CC
and I
OZ
reduced by 50%
n
Outputs source/sink 24 mA
n
'ACT157 has TTL-compatible inputs
n
Standard Microcircuit Drawing (SMD)
-- 'AC157: 5962-89539
-- 'ACT157: 5962-89688
Logic Symbols
Pin Names
Description
I
0a
I
0d
Source 0 Data Inputs
I
1a
I
1d
Source 1 Data Inputs
E
Enable Input
S
Select Input
Z
a
Z
d
Outputs
Connection Diagrams
FACT
TM
is a trademark of Fairchild Semiconductor Corporation.
DS100272-1
IEEE/IEC
DS100272-2
Pin Assignment
for DIP and Flatpak
DS100272-3
Pin Assignment
for LCC
DS100272-4
July 1998
54AC157
54ACT157
Quad
2-Input
Multiplexer
1998 National Semiconductor Corporation
DS100272
www.national.com
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
Outputs
E
S
I
0
I
1
Z
H
X
X
X
L
L
H
X
L
L
L
H
X
H
H
L
L
L
X
L
L
L
H
X
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.
www.national.com
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
)
-0.5V to +7.0V
DC Input Diode Current (I
IK
)
V
I
= -0.5V
-20 mA
V
I
= V
CC
+ 0.5V
+20 mA
DC Input Voltage (V
I
)
-0.5V to V
CC
+ 0.5V
DC Output Diode Current (I
OK
)
V
O
= -0.5V
-20 mA
V
O
= V
CC
+ 0.5V
+20 mA
DC Output Voltage (V
O
)
-0.5V to V
CC
+ 0.5V
DC Output Source
or Sink Current (I
O
)
50 mA
DC V
CC
or Ground Current
per Output Pin (I
CC
or I
GND
)
50 mA
Storage Temperature (T
STG
)
-65C to +150C
Junction Temperature (T
J
)
CDIP
175C
Recommended Operating
Conditions
Supply Voltage (V
CC
)
'AC
2.0V to 6.0V
'ACT
4.5V to 5.5V
Input Voltage (V
I
)
0V to V
CC
Output Voltage (V
O
)
0V to V
CC
Operating Temperature (T
A
)
54AC/ACT
-55C to +125C
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
125 mV/ns
Minimum Input Edge Rate (
V/
t)
'ACT Devices
V
IN
from 0.8V to 2.0V
V
CC
@
4.5V, 5.5V
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
TM
circuits outside databook specifications.
DC Characteristics for 'AC Family Devices
54AC
Symbol
Parameter
V
CC
T
A
=
Units
Conditions
(V)
-55C to +125C
Guaranteed Limits
V
IH
Minimum High Level
3.0
2.1
V
OUT
= 0.1V
Input Voltage
4.5
3.15
V
or V
CC
- 0.1V
5.5
3.85
V
IL
Maximum Low Level
3.0
0.9
V
OUT
= 0.1V
Input Voltage
4.5
1.35
V
or V
CC
- 0.1V
5.5
1.65
V
OH
Minimum High Level
3.0
2.9
I
OUT
= -50 A
Output Voltage
4.5
4.4
V
5.5
5.4
(Note 2)
V
IN
= V
IL
or V
IH
3.0
2.4
I
OH
= -12 mA
4.5
3.7
V
I
OH
= -24 mA
5.5
4.7
I
OH
= -24 mA
V
OL
Maximum Low Level
3.0
0.1
I
OUT
= 50 A
Output Voltage
4.5
0.1
V
5.5
0.1
(Note 2)
V
IN
= V
IL
or V
IH
3.0
0.50
I
OL
= 12 mA
4.5
0.50
V
I
OL
= 24 mA
5.5
0.50
I
OL
= 24 mA
I
IN
Maximum Input
5.5
1.0
A
V
I
= V
CC
, GND
Leakage Current
I
OLD
Minimum Dynamic
Output Current (Note 3)
5.5
50
mA
V
OLD
= 1.65V Max
I
OHD
5.5
-50
mA
V
OHD
= 3.85V Min
3
www.national.com
DC Characteristics for 'AC Family Devices
(Continued)
54AC
Symbol
Parameter
V
CC
T
A
=
Units
Conditions
(V)
-55C to +125C
Guaranteed Limits
I
CC
Maximum Quiescent
5.5
80.0
A
V
IN
= V
CC
Supply Current
or GND
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.
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
@
25C is identical to 74AC
@
25C.
DC Characteristics for 'ACT Family Devices
54ACT
Symbol
Parameter
V
CC
T
A
=
Units
Conditions
(V)
-55C to +125C
Guaranteed Limits
V
IH
Minimum High Level
4.5
2.0
V
V
OUT
= 0.1V
Input Voltage
5.5
2.0
or V
CC
- 0.1V
V
IL
Maximum Low Level
4.5
0.8
V
V
OUT
= 0.1V
Input Voltage
5.5
0.8
or V
CC
- 0.1V
V
OH
Minimum High Level
4.5
4.4
V
I
OUT
= -50 A
Output Voltage
5.5
5.4
(Note 5)
V
IN
= V
IL
or V
IH
4.5
3.70
V
I
OH
= -24 mA
5.5
4.70
I
OH
= -24 mA
V
OL
Maximum Low Level
4.5
0.1
V
I
OUT
= 50 A
Output Voltage
5.5
0.1
(Note 5)
V
IN
= V
IL
or V
IH
4.5
0.50
V
I
OL
= 24 mA
5.5
0.50
I
OL
= 24 mA
I
IN
Maximum Input
5.5
1.0
A
V
I
= V
CC
, GND
Leakage Current
I
CCT
Maximum
5.5
1.6
mA
V
I
= V
CC
- 2.1V
I
CC
/Input
I
OLD
Minimum Dynamic
5.5
50
mA
V
OLD
= 1.65V Max
I
OHD
Output Current (Note 6)
5.5
-50
mA
V
OHD
= 3.85V Min
I
CC
Maximum Quiescent
5.5
80.0
A
V
IN
= V
CC
Supply Current
or GND
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
@
25C is identical to 74ACT
@
25C.
www.national.com
4
AC Electrical Characteristics
54AC
V
CC
T
A
= -55C
Symbol
Parameter
(V)
to +125C
Units
(Note 8)
C
L
= 50 pF
Min
Max
t
PLH
Propagation Delay
3.3
1.0
16.0
ns
S to Z
n
5.0
1.0
12.0
t
PHL
Propagation Delay
3.3
1.0
14.0
ns
S to Z
n
5.0
1.0
11.5
t
PLH
Propagation Delay
3.3
1.0
16.0
ns
E to Z
n
5.0
1.0
12.0
t
PHL
Propagation Delay
3.3
1.0
14.0
ns
E to Z
n
5.0
1.0
11.5
t
PLH
Propagation Delay
3.3
1.0
11.0
ns
I
n
to Z
n
5.0
1.0
9.0
t
PHL
Propagation Delay
3.3
1.0
11.0
ns
I
n
to Z
n
5.0
1.0
9.0
Note 8: Voltage Range 3.3 is 3.3V
0.3V
Voltage Range 5.0 is 5.0V
0.5V
AC Electrical Characteristics
54ACT
V
CC
T
A
= -55C
Symbol
Parameter
(V)
to +125C
Units
(Note 9)
C
L
= 50 pF
Min
Max
t
PLH
Propagation Delay
5.0
1.0
11.5
ns
S to Z
n
t
PHL
Propagation Delay
5.0
1.0
11.5
ns
S to Z
n
t
PLH
Propagation Delay
5.0
1.0
12.0
ns
E to Z
n
t
PHL
Propagation Delay
5.0
1.0
10.0
ns
E to Z
n
t
PLH
Propagation Delay
5.0
1.0
8.5
ns
I
n
to Z
n
t
PHL
Propagation Delay
5.0
1.0
9.0
ns
I
n
to Z
n
Note 9: Voltage Range 5.0 is 5.0V
0.5V
Capacitance
Symbol
Parameter
Typ
Units
Conditions
C
IN
Input Capacitance
4.5
pF
V
CC
= OPEN
C
PD
Power Dissipation
50.0
pF
V
CC
= 5.0V
Capacitance
5
www.national.com
PDF 
ZIP