HD74LS156 Datasheet, PDF (2/7 Pages) Hitachi Semiconductor – Dual 2-line-to-4-Line Decoders / Demultiplexers(with open collector outputs)

HD74LS156
Function Table
• 2-to-4-line Decoder / 1-to-4-line Demultiplexer
Inputs
Outputs
Select
Strobe
Data
B
A
1G
1C
1Y₀
1Y₁
1Y₂
1Y₃
X
X
H
X
H
H
H
H
L
L
L
H
L
H
H
H
L
H
L
H
H
L
H
H
H
L
L
H
H
H
L
H
H
H
L
H
H
H
H
L
X
X
X
L
H
H
H
H
Inputs
Outputs
Select
Strobe
Data
B
A
2G
2C
2Y₀
2Y₁
2Y₂
2Y₃
X
X
H
X
H
H
H
H
L
L
L
L
L
H
H
H
L
H
L
L
H
L
H
H
H
L
L
L
H
H
L
H
H
H
L
L
H
H
H
L
X
X
X
H
H
H
H
H
• 3-to-8-line Decoder / 1-to-8-line Demultiplexer
Inputs
Outputs
Select
C*¹
B
A
Strobe or
Data
(0)
(1)
(2)
(3)
(4)
G*²
2Y₀
2Y₁
2Y₂
2Y₃
1Y₀
(5)
(6)
(7)
1Y₁
1Y₂
1Y₃
X
X
X
H
H
H
H
H
H
H
H
H
L
L
L
L
L
H
H
H
H
H
H
H
L
L
H
L
H
L
H
H
H
H
H
H
L
H
L
L
H
H
L
H
H
H
H
H
L
H
H
L
H
H
H
L
H
H
H
H
H
L
L
L
H
H
H
H
L
H
H
H
H
L
H
L
H
H
H
H
H
L
H
H
H
H
L
L
H
H
H
H
H
H
L
H
H
H
H
L
H
H
H
H
H
H
H
L
Notes: 1. C; input 1C and 2C connected together
2. G; inputs 1G and 2G connected together
3. H; high level, L; low level, X; irrelevant
Rev.3.00, Jul.13.2005, page 2 of 6