AVR-Chat

At 12:36 PM 8/2/2004, you wrote:
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>On 2 Aug 2004 at 10:54, David VanHorn wrote:
> >
> > Sure. Goes without saying that if you draw enough through the resistor to
> > get any significant droop, it will be a problem, at least for ratiometric
> > conversions.
> >
>     Extracted from the Mega8 datasheet:
>     "The ADC has a separate analog supply voltage pin, AVCC. AVCC 
> must     not differ more than ± 0.3V from VCC. See the paragraph “ADC 
> Noise     Canceler” on page 197 on how to connect this pin."
>     Mark Jordan


Well at least for quite a few mega8s out there keep in mind that the avcc 
is probably connected to vcc internal to the chip.
This was discussed at length over at avrfreaks, just want to make sure 
people over here know of the issue.

    http://www.avrfreaks.com/phpBB2/viewtopic.php?t=20967

    So any fancy filtering  on avcc to limit noise or reduce emi  may not 
work as well as expected.

  They may or may not have fixed this on the newr dies, or they perhaps 
just want you to wait for mega88s to fix it.


-carl