HD74AC Datasheet, PDF (41/52 Pages) Hitachi Semiconductor – HD74AC Series Common Information

Design Considerations
0.0 V
Time (ns) (5.0 ns/div)
Key
Vertical Scale Horizontal Scale
Active Driver
1.0 V/Div
50 ns/Div
Forward Crosstalk 0.2 V/Div
5.0 ns/Div
Active Receiver 1.0 V/Div
5.0 ns/Div
This figure shows traces taken on a test fixture designed to
exaggerate the amplitude of crosstalk pulses.
Figure 12 Reverse Crosstalk on PCB Traces
V_CC
4 ^{Volts from VCC}
V_CC = 5.0 V
30%
Gnd ₃
HAZARD
2
SAFE
1
0
0 5 10 15 20 25 30 35 40 45 50
Pulse Width (ns)
Figure 13 High Noise Margin
40