Connection Diagrams
can be used as the data input for a 4-output demultiplexer
application. Each half of the ’AC/’ACT139 generates all four
minterms of two variables. These four minterms are useful in
some applications, replacing multiple gate functions as
shown in , and thereby reducing the number of packages re-
quired in a logic network.
Pin Assignment
for DIP and Flatpak
DS100269-3
Pin Assignment
for LCC
DS100269-6
FIGURE 1. Gate Functions (Each Half)
Truth Table
Inputs
Outputs
E
H
L
L
L
L
A0
X
L
A1
X
L
O0
H
L
O1
O2
H
H
H
L
O3
H
H
H
H
L
DS100269-4
H
H
L
Functional Description
The ’AC/’ACT139 is
a high-speed dual 1-of-4 decoder/
H
L
L
H
H
H
demultiplexer. The device has two independent decoders,
each of which accepts two binary weighted inputs (A0–A1)
and provides four mutually exclusive active-LOW outputs
(O0–O3). Each decoder has an active-LOW enable (E).
When E is HIGH all outputs are forced HIGH. The enable
H
H
H
H
H
H
=
H
L
X
HIGH Voltage Level
LOW Voltage Level
Immaterial
=
=
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