[sdiy] 7400 / 4000 series ICs--compatible?

[Jason Tribbeck]

Hi,

> I was looking for 4046 PLL ICs, found instead CD74HC4046AE  
> which the data sheet sez is "..pin compatible with the 
> CD4046B of the "4000B" series."  Does that mean I can use 
> 7400 in place of the the 4000?  Or do they mean compatible as 
> in "capable of existing together in harmony"...

"Pin compatible" means that the pins have the same names, and perform
the same functions, but you may find that the "magic"
multiplication/division values based on external components are
different.

(I've only used the 74HC40XX devices in digital mode, and I don't know
about the 4046).

The important difference is normally voltage - 4046 should be powerable
with between 5V and 15V (possibly a little around the outside of these
values), whereas the 74HC4046 will probably only be 5V.
-- 
Jason Tribbeck