Curve fit a function for Diode Vf(If) that works with units

Hello all,

I am trying to create a function that gives Vforward for a diode as a function of Iforward.

Start with a log fit based on a series of data points taken from a datasheet which gives three coefficients to build the function.

The function works fine if i keep eveything unitless, however I would very much prefer if the function takes current (A) and returns voltage (V)

Any suggestions on how to modifiy the coefficients to achieve this?

Thanks,

David