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MC74AC139, MC74ACT139
Dual 1-of-4
Decoder/Demultiplexer
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.
Features
• Multifunctional Capability
• Two Completely Independent 1−of−4 Decoders
• Active LOW Mutually Exclusive Outputs
• Outputs Source/Sink 24 mA
• ′ACT139 Has TTL Compatible Inputs
• These are Pb−Free Devices
VCC Eb A0b A1b O0b O1b O2b O3b
16 15 14 13 12 11 10 9
12345678
Ea A0a A1a O0a O1a O2a O3a GND
Figure 1. Pinout: 16−Lead Packages Conductors
(Top View)
PIN ASSIGNMENT
PIN FUNCTION
A0, A1
E
Address Inputs
Enable Inputs
O0−O3
Outputs
TRUTH TABLE
Inputs
E A0 A1 O0
HXX
LLL
LHL
LLH
LHH
H
L
H
H
H
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
Outputs
O1 O2
HH
HH
LH
HL
HH
O3
H
H
H
H
L
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16
1
16
1
MARKING
DIAGRAMS
16
SOIC−16
D SUFFIX
CASE 751B
1
xxx139G
AWLYWW
TSSOP−16
DT SUFFIX
CASE 948F
16
xxx
139
ALYWG
G
1
xxx = AC or ACT
A = Assembly Location
WL or L = Wafer Lot
Y = Year
WW or W = Work Week
G or G = Pb−Free Package
(Note: Microdot may be in either location)
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 6 of this data sheet.
© Semiconductor Components Industries, LLC, 2015
January, 2015 − Rev. 8
1
Publication Order Number:
MC74AC139/D
MC74AC139, MC74ACT139
E A0 A1
DECODER a
O0 O1 O2 O3
E A0 A1
DECODER b
O0 O1 O2 O3
Figure 2. Logic Symbol
Ea
A0a A1a
Eb
A0b A1b
00a
01a 02a
03a 00b
01b 02b
03b
NOTE:
This diagram is provided only for the understanding of logic
operations and should not be used to estimate propagation
delays.
Figure 3. Logic Diagram
FUNCTIONAL DESCRIPTION
The MC74AC139/74ACT139 is a high−speed dual
1−of−4 decoder/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 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.
EE
A0 O0 A0 O0
A1 A1
EE
A0 O1 A0 O1
A1 A1
EE
A0 O2 A0 O2
A1 A1
EE
A0 O3 A0 O3
A1 A1
Figure 4. Gate Functions (Each Half)
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