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

[Scott Gravenhorst]

"rdrake" <rdrake at data2action.com> wrote:
>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"... 

It may be pin for pin compatible, but there are differences.  For one thing, the 74HC part has 3
phase comparators, not the 2 found in 4046.  Also, the HC part will not handle any more than 5
volts, whereas the CD part will go to 15V.  The HC part has a VCO that will run a whole lot higher
in frequency.

>always a newbie, never a Nerd...
>
>bbob drake
>

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