Motorola MC74ACT158D, MC74ACT158N, MC74AC158D, MC74AC158N Datasheet
5-1
FACT DATA
The MC74AC158/74ACT158 is a high-speed quad 2-input multiplexer. It selects
four bits of data from two sources using the common Select and Enable inputs.
The four buffered outputs present the selected data in the inverted form. The
MC74AC158/74ACT158 can also be used as a function generator.
• Outputs Source/Sink 24 mA
• ′ACT158 Has TTL Compatible Inputs
1516 14 13 12 11 10
21 3 4 5 6 7
V
CC
9
8
E
I0cI
1c
Z
cI0dI1dZd
S I
0aI1a
Z
aI0bI1bZb
GND
PIN NAMES
I0a–I
0d
Source 0 Data Inputs
I1a–I
1d
Source 1 Data Inputs
E
Enable Input
S Select Input
Z
a–Zd
Inverted Outputs
TRUTH TABLE
Inputs Outputs
E S I
0I1
Z
H X X X H
L L L X H
L L H X L
L H X L H
L H X H L
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
QUAD 2-INPUT
MULTIPLEXER
N SUFFIX
CASE 648-08
PLASTIC
D SUFFIX
CASE 751B-05
PLASTIC
LOGIC SYMBOL
S
E I0aI1aI0bI
1b
Z
b
I0cI1cI0dI
1d
Z
a
Z
c
Z
d
MC74AC158 MC74ACT158
5-2
FACT DATA
FUNCTIONAL DESCRIPTION
The MC74AC158/74ACT158 quad 2-input multiplexer
selects four bits of data from two sources under the control of
a common Select input (S) and presents the data in inverted
form at the four outputs. The Enable input (E
) is active-LOW.
When E
is HIGH, all of the outputs (Z) are forced HIGH
regardless of all other inputs. The MC74AC158/74ACT158 is
the logic implementation of a 4-pole, 2-position switch where
the position of the switch is determined by the logic levels
supplied to the Select input.
A common use of the MC74AC158/74ACT158 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 MC74AC158/
74ACT158 can generate four functions of two variables with
one variable common. This is useful for implementing gating
functions.
LOGIC DIAGRAM
I
0a
I
1a
I
0b
I
1b
I
0c
I
1c
I
0d
I
1d
E S
Z
a
Please note that this diagram is provided only for the understanding of logic
operations and should not be used to estimate propagation delays.
Z
b
Z
c
Z
d
MAXIMUM RATINGS*
Symbol Parameter Value Unit
V
CC
DC Supply Voltage (Referenced to GND) –0.5 to +7.0 V
V
in
DC Input Voltage (Referenced to GND) –0.5 to VCC +0.5 V
V
out
DC Output Voltage (Referenced to GND) –0.5 to VCC +0.5 V
I
in
DC Input Current, per Pin ±20 mA
I
out
DC Output Sink/Source Current, per Pin ±50 mA
I
CC
DC VCC or GND Current per Output Pin ±50 mA
T
stg
Storage Temperature –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.
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