HD74HC155 Datasheet, PDF (1/9 Pages) Hitachi Semiconductor – Dual 2-to-4-line Decoders/Demultiplexers

HD74HC155
Dual 2-to-4-line Decoders/Demultiplexers
Description
This circuit features dual 1-line-to-4-line demultiplexer with individual strobes and common binary-address
input. When both sections are enabled by the strobes, the common binary-address inputs sequentially
select and route associated input data to the appropriate output of each section. The individual strobes
permit activating or inhibiting each of the 4-bit sections as desired. Data applied to input 1C is inverted
through its outputs. The inverter following the 1C data input permits use as a 3-to-8-line decoder or 1-to-8-
line demultiplexer without external gating.
Features
• High Speed Operation: t_pd (A or B to Y) = 15 ns typ (C_L = 50 pF)
• High Output Current: Fanout of 10 LSTTL Loads
• Wide Operating Voltage: V_CC = 2 to 6 V
• Low Input Current: 1 µA max
• Low Quiescent Supply Current: I_CC (static) = 4 µA max (Ta = 25°C)
Function Table
2-line-to-4-line Decoder/1-line-to-4-line Demultiplexer
Inputs
Select
B
A
X
X
L
L
L
H
H
L
H
H
X
X
Strobe
Data
Outputs
1G
1C
H
X
1Y₀
1Y₁
1Y₂
1Y₃
H
H
H
H
L
H
L
H
H
H
L
H
H
L
H
H
L
H
H
H
L
H
L
H
H
H
H
L
X
L
H
H
H
H