Inductor Simulation with current

[beorza]

Hi everybody

Question: I designed a helical inductor 130uH with the range of current from 0ADC to 35ADC I tested that inductor in the workbench and I got the chart how the inductance decreases with the current. With this chart I got the equation of that curve L(uh)= 130-55*((tanh(x/15)^4). I followed the LTspice example " Flux= 1m*thanh(5*x).
I added my equation to the model "Flux=130u -55u*pow(tanh(x/15),4)". Unfortunately the chart I got from LTspice is opposite (curve is going up). Do you have any idea what I missed or did I make something wrong?

I really appreciate you help

Thank you very much and have a wonderful day

 

[Prototyp_V1.0]

Just a suggestion - maybe that chart show reactance instead of inductance ?

 

[beorza]

Just a suggestion - maybe that chart show reactance instead of inductance ?

Thank you for your answer

This is the equation I have for my coil, Flux=14u-4u*(pow(tanh(x/49),4))
If I put that one in the boost converter it gives and output value larger (more then 10V) than I expected. it is a boost converter from 3.3 V to 5.0 V. If I multiply by -1 , Flux=-14u+4u*(pow(tanh(x/49),4)) it works. I do not understand why, supposedly LTspice should take the original equation.

Thanks

 

[vfone]

Usually, the inductance decrease with increase of DC current:

https://epci.eu/wp-content/uploads/2019/10/Fig.-2.47-Standardised-curve-WEPD.jpg

https://d10lvax23vl53t.cloudfront.net/image-handler/ts/20190503124351/ri/514/src/images/Article_Images/ImageForArticle_1645(2).jpg

https://datasheet.lcsc.com/szlcsc/Sunlord-WPN201610UF1R0MT_C316331.pdf