[sdiy] Tempco 2k +3350ppm Group buy

[René Schmitz]

Ian Fritz wrote:

> Right.  What I was getting at is that manufacturers sometimes have odd 
> ways of specifying their devices, and you have to watch out for that as 
> well as for nonlinearities.  I agree that the nonlinearities can often 
> distort how tempcos are characterized.  For example, if you use 
> measurements at 25C and 100C to define the tempco you will get a 
> different result than if you use 25C and 30C.  Probably using 
> measurements at 12C and 32C with reference to 22C and a target of 3390 
> ppm/K would be the best for our work.  But you never seem to see that.

Still, I don't see how (linearity provided) the tangent would be any 
different from the slope. :-)

I would expect a linear ideal 3354ppm 1k resistor to show
1K + (t-25°C)*3.354Ohms/K. Or R(T) = 3.354Ohms/K * T.
I think this way of writing it is a lot more clear than this whole 
buissiness with ppm/K.

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159