I did a test board with the LT3990 similar to the "typical applications" on page 18 of the data sheet.
Vin 30 to 62V
Vout set to 24V instead of 12V / R1 = 1M / R2 = 53k6
f = 1MHz
C3 = 0.1uF
L1 = 33uH / 0.5A Type WE 744 383 353 30
Device runs perfect with load up to 150mA
Output Short Circuit protection work perfect!
Problem: if I increase the output load current, the LT3990 become damaged.
What can be wrong in this configuration?