Datasheet

6
Test Circuits and Waveforms
FIGURE 1. HC AND HCU TRANSITION TIMES AND PROPAGA-
TION DELAY TIMES, COMBINATION LOGIC
FIGURE 2. HCT TRANSITION TIMES AND PROPAGATION
DELAY TIMES, COMBINATION LOGIC
t
PHL
t
PLH
t
THL
t
TLH
90%
50%
10%
50%
10%
INVERTING
OUTPUT
INPUT
GND
V
CC
t
r
= 6ns t
f
= 6ns
90%
t
PHL
t
PLH
t
THL
t
TLH
2.7V
1.3V
0.3V
1.3V
10%
INVERTING
OUTPUT
INPUT
GND
3V
t
r
= 6ns
t
f
= 6ns
90%
CD54/74HC157, CD54/74HCT157, CD54/74HC158, CD54/74HCT158