SN74LV138AT Datasheet, PDF (2/20 Pages) Texas Instruments – 3-LINE TO 8-LINE DECODER/DEMULTIPLEXER

SN74LV138AT
3-LINE TO 8-LINE DECODER/DEMULTIPLEXER
SCLS691 – AUGUST 2005
www.ti.com
DESCRIPTION/ORDERING INFORMATION (CONTINUED)
The conditions at the binary-select inputs (A, B, C) and the three enable inputs (G1, G2A, G2B) select one of
eight output lines. The two active-low (G2A, G2B) and one active-high (G1) enable inputs reduce the need for
external gates or inverters when expanding. A 24-line decoder can be implemented without external inverters
and a 32-line decoder requires only one inverter. An enable input can be used as a data input for demultiplexing
applications.
This device is fully specified for partial-power-down application susing I_off. The I_off circuitry disables the outputs,
preventing damaging current backflow through the device when it is powered down.
FUNCTION TABLE
ENABLE INPUTS
G1
G2A G2B
X
H
X
X
X
H
L
X
X
H
L
L
H
L
L
H
L
L
H
L
L
H
L
L
H
L
L
H
L
L
H
L
L
SELECT INPUTS
C
B
A
X
X
X
X
X
X
X
X
X
L
L
L
L
L
H
L
H
L
L
H
H
H
L
L
H
L
H
H
H
L
H
H
H
OUTPUTS
Y0
Y1
Y2
Y3
Y4
Y5
Y6
Y7
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
L
2