Anne, I would go for 3 V if the Microchip specs say you can.  I would assume
that the 3 V limit is conservative enough that the device will work reliably
if Microchip are prepared to say that it will - I think do not think that
Microchip would take the chance that the product will not work reliably,
since the reputation of all their product rests on it.. If you can't trust
the specs, what can you trust??  If you can't trust this spec, which can you
trust?... etc.

Just make sure that your supply is stable enough never to drop below 3 V
(this might be a reason to go for a slightly higher voltage)..

Cheers
 Roland

----- Original Message -----
From: Anne Ogborn <anniepoo@NETMAGIC.NET>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: 23 August 1999 23:32
Subject: 16c558 on 3.0v


> MicroChip says the lowest voltage I can operate the
> 16C558 on is 3.0V
>
> ISD says I have to supply 2.7 to 3.3V to the ISD chip
>
> Anybody with a good suggestion what my actual design
> goal for Vcc should be?  3.15V would split the difference
> between the 3.3V upper bound and the 3.0V lower bound.
> But I know that limits are what you make them. So, anybody
> who'se run a PIC chip in a 3V logic family circuit who can
> advise?
>
> Also, I need to clock with a XTAL (I need the timebase),
> will it work reliably at 3.0V???
>
> Annie doesn't like running at the ragged edge of her
> voltage spec.
>
>
> --
> Anniepoo
> Need loco motors?
> http://www.idiom.com/~anniepoo/depot/motors.html
>