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

[James Patchell]

The answer to that is Yes and No...

The devices can operate from 3 to 18 volts, but are only tested for 5, 10 
and 15 volt operation....all this means is that at 3 volts, they are not 
tested to perform at a particular level...generally this is speed.  If you 
don't care how fast they are, using them at 3 volts is fine.

At 05:32 PM 8/27/2005 -0400, Roy J. Tellason wrote:
>On Saturday 27 August 2005 03:51 pm, Phil Harbison 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
> > 74HCxx:  Vdd +5V, CMOS compatible input levels
> > 74HCTxx: Vdd +5V, TTL compatible input levels
>
>I was of the impression that the 4xxx B-series devices would go down to 3V...

         -Jim
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