Re: [CAD_CAM_EDM_DRO] CMOS supply rails

Bill Vance wrote:

>Howdy;
>
>I'm starting to get some parts and pieces together for some experimental DRO
>circuits, but I've got a question I haven't been able to find an answer to.
>
>The original A and B series CMOS chips, as well as the C series, (74CXX) have a
>plus Volts rating of +15 to +18 Volts. The HC series, (74HCXX), seems to be
>much easier to find than the C series, but the only data I've been able to find
>on them shows a +5 or +6 Volt supply rail. Does the HC series have the same
>rating as the others, but use the +5 or +6 Volt numbers to show compatability
>with TTL, or what?
>
>

The original CMOS 4000 series was good to 15 V. There were some devices
also
made with the 74Cxx part numbers, but the 4000 series has a much wider
selection
of parts. The 74HC (and HCT) parts ARE NOT the same thing, whatsoever.
They
are 5 x faster, but cannot accept the 15 V power. They will fail
between 6 and 7 V.

Digi-Key still carries half a page of 4000 series part numbers.

Jon