[sdiy] Transistor Matching

[Tim Ressel]

Yo,

Aha!!!!

It seems I was having a noise problem. I sprinkled
caps all over the circuit and the offset problem all
but disapeared. The offset is down to 2mV. 

--tr



--- Grant Richter <grichter at asapnet.net> wrote:
> The Moog app note says 2 millivolts, but by grading
> them into 1 millivolt
> bins, you can easily match to 1 millivolt.
> 
> Silicon changes around 2 millivolts per degree C
> (variously quoted by
> references any where between 1.8 and 2.7 mv/C)
> 
> So the Moog spec assumes a possible error of 1
> degree C.
> 
> BTW, the exact value of the current source is not
> important, only that it be
> repeatable.
> 
> > By the way, do you know how close transistors need
> to
> > be? What is a good matching number to shoot for?
> > 
> 


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