74LCX138 Datasheet, PDF (2/12 Pages) Fairchild Semiconductor – Low Voltage 1-of-8 Decoder/Demultiplexer with 5V Tolerant Inputs

Connection Diagrams
Pin Assignments for SOIC, SOP, and TSSOP
Pin Descriptions
Pin Names
A₀–A₂
E₁–E₂
E₃
O₀–O₇
Description
Address Inputs
Enable Inputs
Enable Input
Outputs
Pad Assignments for DQFN
Functional Description
The LCX138 high-speed 1-of-8 decoder/demultiplexer
accepts three binary weighted inputs (A₀, A₁, A₂) and,
when enabled, provides eight mutually exclusive active-
LOW outputs (O₀–O₇). The LCX138 features three Enable
inputs, two active-LOW (E₁, E₂) and one active-HIGH (E₃).
All outputs will be HIGH unless E₁ and E₂ are LOW and E₃
is HIGH. The LCX138 can be used as an 8-output demulti-
plexer by using one of the active LOW Enable inputs as the
data input and the other Enable inputs as strobes. The
Enable inputs which are not used must be permanently tied
to their appropriate active-HIGH or active-LOW state.
(Top Through View)
Truth Table
Inputs
Outputs
E₁ E₂ E₃ A₀ A₁ A₂ O₀ O₁ O₂ O₃ O₄ O₅ O₆ O₇
HX X X X X HHHHHHHH
X HX X X X HHHHHHHH
XX L XXXHHHHHHHH
L
L
H
L
L
L
L
HH
H
H
H
H
H
L
L
H
H
L
L
H
L
H
H
H
H
H
H
L
L
H
L
H
L
HH
L
H
H
H
H
H
L
L
H
H
H
L
HHH
L
H
H
H
H
L
L
H
L
L
H
HHH
H
L
H
H
H
L
L
H
H
L
H
HHH
H
H
L
H
H
L
L
H
L
H
H
HHH
H
H
H
L
H
L
L
H
H
H
H
HHH
H
H
H
H
L
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
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