[sdiy] CEM3374 vco temp sensor

[James Patchell]

I have been corrected....what I said was incorrect....

At 07:48 PM 10/16/2003 -0700, James Patchell wrote:
>I never used the 3374, but I think the idea was to take the temp sensor 
>output and use that for the reference for the D/A converter that will be 
>controlling the pitch.  The D/A will essentially provide the 
>multiplication function.  You could also use the voltage to control the 
>gain of an OTA much like I have done on one of my VCO's
>
>http://www.oldcrows.net/~patchell/synthmodules/100-1007.pdf
>
>I use an LM13700 or LM13600 to make a very linear two quadrant multiplier.
>
>At 03:54 AM 10/17/2003 +0200, Karl Dalen wrote:
>>The CEM3374 dual VCO have a temp sensor, i asume
>>it uses bandgap design but how does that achieve the
>>+3500ppm scaling, does it perhaps use a 3340 multiplier?
>>
>>Its no doubt that it works splendid but how sure
>>could one be that the temp drift are equal on both
>>VCO's?
>>
>>It also say that a +/-90mv covers a 10 octave range
>>wouldent that put quite some precision requirements
>>on the OP amps in the DAC reference feedback path
>>in terms of V offset drift with TC?!
>>
>>Are there any +3300/3500 silicon temp sensor availabe
>>on the market? Perhaps it would be more linear then a
>>NTC, No? Just speculating a bit!
>>
>>KD
>>
>>Höstrusk och grå moln - köp en resa till solen på Yahoo! Resor på 
>>adressen http://se.docs.yahoo.com/travel/index.html
>
>         -Jim
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>
>Man's Prayer
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>

         -Jim
***************************************************
I'm a man
But I can change
If I have to
I guess.

Man's Prayer
Red Green

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http://www.oldcrows.net/~patchell

http://members.cox.net/patchell

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