Calculating an equation to fit a voltage range to log scale

Thread Starter

sindre jacobsen

Joined Apr 1, 2019
40
Hello
I am currently trying to fit a voltage range to an output of a antilog circuit I will be designing.
Here are some of the details:
At 2V output on the antilog amp, the input is 2.85V. At a point 7 dB lower, the output is 0.893 V, while the input is 2.2V.
Anyone who got any ideas on how to attack this problem? I am currently thinking of trying to reparameterize the input so that the output is in the form of 10^u, where u is proportional to the input voltage.
Hope anyone can help.
Thanks
 

MrChips

Joined Oct 2, 2009
34,807
You have provided two data points.
You can fit an infinite number of models to two data points.
We may be able to provide some assistance if you provided more data points. More would be better than few.
Four data pairs would be the minimum. Ten points would be much better.
 

Thread Starter

sindre jacobsen

Joined Apr 1, 2019
40
upload_2019-7-24_18-37-20.pngupload_2019-7-24_18-38-47.png
Went a little overboard with the points, but wanted to try forming an equation with the axis-intersect, but the slope of the equation did not fit...
 

Thread Starter

sindre jacobsen

Joined Apr 1, 2019
40
You have provided two data points.
You can fit an infinite number of models to two data points.
We may be able to provide some assistance if you provided more data points. More would be better than few.
Four data pairs would be the minimum. Ten points would be much better.
Thanks for providing me with an "aha" moment! :)
Figured out the equation: Vctrl = 0.05797*10^(Vshape/1.854) ... If anyone was wondering :)
 
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