uC favorites?

On Thu, 29 Apr 2004 16:29:03 +0200, the renowned "Fred Bartoli"
<fred._canxxxel_this_bartoli@RemoveThatAlso_free.fr_AndThisToo> wrote:

>
>"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> a &#4294967295;crit dans le message
>news: s7e090hmiiu7kj8aup5debfmhoc5o6u27f@4ax.com...
>> On Thu, 29 Apr 2004 10:56:05 +1200, the renowned Jim Granville
>> <no.spam@designtools.co.nz> wrote:
>> >
>> >Vref stability is a matter for the fine print. ALL Vrefs will differ
>> >from unit to unit, and also vary over temperature.
>> >  The key point is, by how much ?
>> >
>> >[They quote 2.44V, or 2.43V Typical as Vref, so 'about 2.4401' does not
>> >sound too terrible ? ]
>> >
>> >  Their spec also says typ 15ppm/'C tempco.
>> >That's not the very best, but Maxim sell plenty of Vrefs worse than
>> >that. Remember this is an ON-CHIP, Vref.
>>
>> An on-chip Vref has the disadvantage that it is at the die temperature
>> for the micro. No big deal if the micro is running at a couple of mA
>> and not switching much, but if it is running hot you can get
>> objectionable (perhaps on cosmetic grounds) drift during warm-up.
>>
>
>
>If you have a power hungry uC and plenty of unused CPU time then you have
>die temperature control for (almost) free.
>Fred.

Assuming you have an on-chip temperature sensor, just sleep the CPU to
maintain a constant die temperature? Or perhaps load some outputs
heavily? How to turn a complex mixed-signal microcontroller into a
LM199? 



Best regards, 
Spehro Pefhany
-- 
"it's the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
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"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> a &#4294967295;crit dans le message
news: ua5290dg7186hr5091lj2um8h60fmbr9ae@4ax.com...
>
> >If you have a power hungry uC and plenty of unused CPU time then you have
> >die temperature control for (almost) free.
> >Fred.
>
> Assuming you have an on-chip temperature sensor, just sleep the CPU to
> maintain a constant die temperature? Or perhaps load some outputs
> heavily? How to turn a complex mixed-signal microcontroller into a
> LM199?
>
>

One have plenty of temperature sensors on a uC. Don't they have lots of
available inputs ? (just use the clamping diodes).
That way you could even have temperature mapping of the die, well at least
at the periphery. Taking it a bit further then you can fine tune the code
(which die area gets to switch) so as to draw an IR image on the die.

Oh yes, that *slow* scan IR TV could well be as entertaining as ordinary
programmes.

Thanks,
Fred.