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

[Scott Gravenhorst]

Phil Harbison <alvitar at comcast.net> wrote:
>
>I'm not familiar with that specific part, but the differences
>between 40xx, 74HCxx, and 74HCTxx parts are primarily related
>to supply voltage and input thresholds.
>
>40xx:    Vdd ranges from +5V to +15V

I've seen data sheets that show min. Vdd at 3V.

>74HCxx:  Vdd +5V, CMOS compatible input levels
>74HCTxx: Vdd +5V, TTL compatible input levels
>

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