🚀 go-pugleaf

I seem to remember having been told a few years ago that there were
problems with the 4000 Series CMOS process IC's that made them less
desirable for some applications.  I can't remember what the properties
were that caused problems, perhaps:

   - Susceptibility to lockup
   - Particularly bad problems with noisy power
   - etc....

The "rule of thumb" I was given was to try using the 74C style CMOS
instead.

Does anyone know what (if any) problems/risks/etc might be involved in
using 4000 series parts (particular to that family)?

From a high level, I have seen a system using 4000 parts apparently
"lock up", but the design looks OK for what I was taught with 74CXXX
parts.  Might there be some 4000 family sensitivities in there?  It used
to be the case that 4000 series CMOS used a different fabrication
process from the 74CXXX series.  Is this still true?

Thanks in advance for any help....

				-- Don
-- 
=============================================================================
Don Kark                        |  don@wilbur.coyote.trw.com
TRW Inc.                        |  dora!dkark@csn.org
Denver, CO			|