We are using LM5069 in the below circuit. Under most circumstances the design is functional but after some time we experience failure of Q1. Replacing Q1 resolves the issue until the next failure.
We believe that we have followed all relevant design considerations even considering the SOA of the MOSFET but our best guess is that we are exceeding the SOA of the MOSFET.
We did notice that the LM5069 evaluation kit uses a back to back MOSFET design, but in the evaluation kit two different MOSFETs are in use with different gate thresholds. Is this relevant? Does it aid with sequencing during turn on / turn off events?
