We are using the LT8316 as a buck converter for 400V to 15V. The Componets ar selected to run up to 3A.
As a test voltage we used 100V. The buck converter works well with low current. But when we increase the current, the circuit fails and the LT8316 gets destroyed.
We measure a short circuit from BIAS to GND.
Do you have any idea, why we can't get more then 500mA, before the LT8316 gets destroyed?
My schematics and layout are shown below.