[sdiy] Stereo MOOG filter / sharing expo convertors

[Grant Richter]

See the Burr-Brown REF200 chip.

http://focus.ti.com/docs/prod/folders/print/ref200.html

On May 9, 2007, at 7:39 PM, Paul Perry wrote:

> Following on, is there a simple way to generate a current that is a  
> fixed
> ratio of another current? (you can see where I'm going with this...  
> one exp
> converter to control two harmonically related frequencies, for  
> example).
> I think at the silicon level it is done using transistors with  
> ratios of
> area (I could of course be completely wrong about that).
>
> Paul perry Melbourne Australia
>
> -----Original Message-----
>
> Using one current source with multiple
> transistors should work wery well. I'd use
> a monolythic transistor array, like a CA3046
> (for low cost) or a MAT-04 for better matching.
> They should track excellently, imho.
> H^) harry
>
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