Easy Excel Hacks - a.k.a becareful of what notes you put into your files

[16bitanalogue]

I thought this was actually funny - and also helped me know that I wasn't the only one who had trouble understanding TI datasheet equations.
TI's LMR33630-Q1 buck converter datasheet has several output capacitor equations for us lowly customers to design our circuits with. All well and good. But tell me dear reader, if you read the equations in the datasheet for COUT, they seem very complicated!
I know I can refer back to my old notes, Robert Erickson's "Fundamental's of Power Electronics" or the numerous trainings by Basso to calculate an appropriate COUT value for a buck converter but god damn. I have seen many datasheets, forum posts, design notes, etc. where equations may differ depending on variable names which can be a little bit of a pain. Look at this equation:

This is not obvious to me, I know how to calculate for COUT but this equation is strange. I am not the only one who thinks so, and if you go to TI's E2E forum you can find several threads about how to derive this particular equation. None of the threads answer the question; rather, most say "read this IEEE paper", "read Erickson's book", "Our Excel calculator matches the datasheet equation."

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1248817/lmr33630-design-equations-in-section-9-2
https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/868717/lmr33630-q1-derivation-process-of-output-capacitance-formula
https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1191667/lmr33630-q1-the-different-of-the-calculation-of-cout-value

Sure sure. But I have OCD and I want to know how the hell you arrived at this equation like other posters.

The funny part. TI does provide an Excel calculator with some calculation sheets hidden. It is password protected, but this is Excel password protection which sucks. Getting passed the Excel sheet protection, there is a sheet with "notes". In the notes written from the TI engineer (emphasis mine):


Now that is hilarious.

Happy New Year, y'all.