VCO temp compensation

[Paul Maddox]

Paul,

>
>But, it occurs to me that temperature sensing chips are pretty cheap
>now and more importantly are available.
>Couldn't an oscillator be designed where a compensating voltage was
>derived from the sensor? I'm not talking perfection, just something that
>most people wd be happy with when gigging.
>

Ive wondered this too, one problem though... getting a good thermal contact 
with whatever you're using for the log convertor.

Another thing Ive been thinking of..

Correct me if Im wrong but the collector current changes with heat, yes? 
hence the problem... so ona transistor array, why not use this to feedback, 
somehow, into the lgo convertor, surely it will have the same amount of 
drift per degC as the convertor, it may need to be inverted but this would 
surely save people trying to find 2k3300ppmdegC tempcos.

naff idea?

Paul


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