5-1
FACT DATA
C0068C0117C0097C0108 C0049C0262C0111C0102C0262C0052 C0068C0101C0099C0111C0100C0101C0114C0047C0068C0101C0109C0117C0108C0116C0105C0112C0108C0101C0120C0101C0114
The MC74AC139/74ACT139 is a high-speed, dual 1-of-4 decoder/demultiplexer.
The device has two independent decoders, each accepting two inputs and providing
four mutually-exclusive active-LOW outputs. Each decoder has an active-LOW
Enable input which can be used as a data input for a 4-output demultiplexer. Each
half of the MC74AC139/74ACT139 can be used as a function generator providing
four minterms of two variables.
• Multifunction Capability
• Two Completely Independent 1-of-4 Decoders
• Active LOW Mutually Exclusive Outputs
• Outputs Source/Sink 24 mA
• ′ACT139 Has TTL Compatible Inputs
1516 14 13 12 11 10
21 3 4 5 6 7
V
CC
9
8
E
b
A
0b
A
1b
E
a
GND
O
0b
O
1b
O
2b
O
3b
A
0a
A
1a
O
0a
O
1a
O
2a
O
3a
PIN NAMES
A
0
, A
1
Address Inputs
E Enable Inputs
O
0
–O
3
Outputs
TRUTH TABLE
Inputs Outputs
E A
0
A
1
O
0
O
1
O
2
O
3
H X X H H H H
L L L L H H H
L H L H L H H
L L H H H L H
L H H H H H L
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
C0077C0067C0055C0052C0065C0067C0049C0051C0057
C0077C0067C0055C0052C0065C0067C0084C0049C0051C0057
DUAL 1-OF-4
DECODER/DEMULTIPLEXER
N SUFFIX
CASE 648-08
PLASTIC
D SUFFIX
CASE 751B-05
PLASTIC
E A
0
A
1
O
0
O
1
O
2
O
3
DECODER a
LOGIC SYMBOL
E A
0
A
1
O
0
O
1
O
2
O
3
DECODER b