TPS650864: Request to review Inductor values

Hi Tom,

Thank you for your post.

I have reviewed with the calculators and find the following:

1. BUCK1: with a ripple current ratio K(ind) = 0.3, I calculated a value of 252 nH as "optimal"; 600 nH was closer to 0.125; both are fine, just a note. 

2. For BUCK3/4/5, we recommend using 470 nH, even for the lower currents. The internal compensation is optimized for 470 nH so overall stability should be best at this inductance. The calculators in the datasheet for inductance are specifically for the DCAP2 BUCK1/2/6. Additionally, the size seems very large. Generally something like DFE322512F-R47M# as a more optimal tradeoff between size/cost & DCR. 

3. For the capacitors, generally 5x22uF GRM188R60J226MEA0# tend to be cheaper / more space efficient than the larger 1210 100 uF cases and they have lower ESR / ESL. Again, just a suggestion. There are likely additional capacitors on these lines near the Xilinx MPSoC so ESR/ESL are likely not critical for these bulk capacitors.