LM5116: LM5116-12EVAL inductor value not correct ?

Hello Hubb 

20-40% is just a typical guideline. Designers can choose 15% or 45% for example if required. Usually, Inductor size and temperature are reduced, and MOSFET temperatures increases by choosing higher ripple ratio. 

- Eric Lee

In order to get to 10uH , i had to increase the ripple to 80% of ILoad. That is twice the amount you suggested.

The other way to get to 10uH would be to double the switching frequency to ~500kHz.  The eval board switching frequency is set to 250kHz.

I dont understand which inductor value to by.

Hello Hubb 

The ripple ratio changes by changing VIN. At Min VIN, it is 19%. At Max VIN, it is 82%.  It is around 40% at 24V

- Eric Lee

So i assume there is no right or wrong. The designer decides how much ripple is acceptable then.probably a good idea to design around a Vin the circuit will most likely run on.