HD74AC Datasheet, PDF (35/52 Pages) Hitachi Semiconductor – HD74AC Series Common Information

Design Considerations
ECL
D3
620
5.0V
510
AC
D1
D2
T1
620
T1,T2 - 2SC641 (K)
D1,D2 - HP5082 - 2811
D3 - IN414 OR IN 4148
–5.2V
Figure 6 Differential Output ECL-to-HD74AC Circuit
It should be understood that for FACT, as with other CMOS technologies, input levels that are between
specified input values will cause both transistors in the CMOS structure to be conducting. This will cause a
low resistive path from the supply rail to ground, increasing the power consumption by several orders of
magnitude. It is important that CMOS inputs are always driven as close as possible to the rail.
Figure 7 Crystal Oscillator Circuit Implemented with FACT HD74AC00
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