On Feb 26, 12:15*am, Matty-t wrote:

4000/7400/8000/9000 series parts ...
...I am looking for a close to complete and valid cross
reference guide. I know a few of these can be used in place of others,
but am looking to validate that. has anyone compiled a good cross for
these yet? TIA.

Not likely. There are 'replacement guides' that marketing
departments use to steer customers to their employer,
but in general the info made available is as much FUD
as possible.

I recall Fairchild once noted that their 4000 CMOS was
compatible with their LSTTL because the temperature
tracking meant that worst-case current for CMOS was
at high temperature, but worst-case current for LSTTL
was at low temperature. So, they claimed all Fairchild
4000 series would drive any Fairchild LSTTL, at equal
temperatures, THEN cautioned that the same 'might not'
hold true of any other manufacturer's parts.

RCA had a completely different analysis of TTL/CMOS
compatibility. You could never be sure if the RCA
part and the Fairchild part were compatible, not from
the data sheet, nor from the ancillary claims.