At 05:46 PM 12/1/2005 -0500, you wrote:
> > > Of
> > > course at 3.3V, you can't get the 25mA you can get at 5V, but
> > > that's not
> > > the USART's problem.
> >
> > Eh!?  Where does it say that on the datasheet!?
> > Why of course?
>
>Because the output device is a FET, AKA a resistor.
>
>Output current into any resistive load will always be lower, with lower
>VCC.

Draw enough current and it no longer acts much like a resistor and
becomes a (crummy) current source (once the output drop exceeds Vth,
approximately). This may be within abs. max. current specifications at
lower supply voltages.

>Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
->> Inexpensive test equipment & parts http://search.ebay.com/_W0QQsassZspeff


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