MC74AC139 ON Semiconductor, MC74AC139 Datasheet - Page 2

• Manufacturer Part Number: MC74AC139
• Description: Dual 1-of-4 Decoder / Demultiplexer
• Manufacturer: ON Semiconductor

1–of–4 decoder/demultiplexer. The device has two
independent decoders, each of which accepts two binary
weighted inputs (A
exclusive active–LOW outputs (O
an active–LOW enable (E). When E is HIGH all outputs are
forced HIGH. The enable can be used as the data input for
a 4–output demultiplexer application. Each half of the
MC74AC139/74ACT139 generates all four minterms of
two variables. These four minterms are useful in some
applications, replacing multiple gate functions as shown in
Figure 4, and thereby reducing the number of packages
required in a logic network.
The MC74AC139/74ACT139 is a high–speed dual
FUNCTIONAL DESCRIPTION
0
–A
1
) and provides four mutually
NOTE:
0
–O
This diagram is provided only for the understanding of logic
operations and should not be used to estimate propagation
delays.
3
). Each decoder has
MC74AC139, MC74ACT139
Figure 3. Logic Diagram
Figure 2. Logic Symbol
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E
2
A
A
A
A
A
A
A
A
E
E
E
E
0
1
0
1
0
1
0
1
Figure 4. Gate Functions (Each Half)
O
O
O
O
0
1
2
3
A
A
A
A
A
A
A
A
E
E
E
E
0
1
0
1
0
1
0
1
O
O
O
O
0
1
2
3