HD74AC HITACHI [Hitachi Semiconductor], HD74AC Datasheet - Page 35

• Manufacturer Part Number: HD74AC
• Description: HD74AC Series Common Information
• Manufacturer: HITACHI [Hitachi Semiconductor]

Design Considerations
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.
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Figure 7 Crystal Oscillator Circuit Implemented with FACT HD74AC00
Figure 6 Differential Output ECL-to-HD74AC Circuit
ECL
620
D3
D1
T1
620
510
D2
–5.2V
T1,T2 - 2SC641 (K)
D1,D2 - HP5082 - 2811
D3 - IN414 OR IN 4148
5.0V
AC