HD74LS155 Datasheet, PDF (4/7 Pages) Hitachi Semiconductor – Dual 2-line-to-4-line Decoders/Demultiplexers

HD74LS155
Switching Characteristics
(V_CC = 5 V, Ta = 25°C)
Item
Symbol
Inputs
Output
Levels
of logic
min.
typ.
max.
Unit Condition
t_PLH
A, B, 2C
Y
2
—
10
15
ns
t_PHL
1G or 2G
—
19
30
ns
Propagation
t_PLH
A or B
Y
delay time
t_PHL
3
—
17
26
ns
C_L = 15 pF,
—
19
30
ns
R_L = 2 kΩ
t_PLH
1C
Y
3
—
18
27
ns
t_PHL
—
18
27
ns
Testing Method
Test Circuit
4.5V
P.G.
Zout = 50Ω
Input
V_CC Output
RL ^{Load circuit 1}
1Y0
CL
1G
Output
1C
1Y1
Same as Load Circuit 1.
B
Output
A
1Y2
Same as Load Circuit 1.
Output
2C
1Y3
Same as Load Circuit 1.
2G
Output
2Y0
Same as Load Circuit 1.
Output
2Y1
Same as Load Circuit 1.
Output
2Y2
Same as Load Circuit 1.
Output
2Y3
Same as Load Circuit 1.
Notes: 1. C_L includes probe and jig capacitance.
2. All diodes are 1S2074(H).
Rev.2.00, Feb.18.2005, page 4 of 6