this note describes the MOSFET body diode recovery mechanism in a phase-shifted ZVS full bridge DC/DC converter
The document describes the Phase-Shifted Zero Voltage Switching (ZVS) Full Bridge topology, explaining how it utilizes parasitic elements to eliminate power losses during switching transitions. It details the circuit configuration involving four switches with intrinsic body diodes and output capacitances.
High dv/dt values can turn on the intrinsic bipolar transistor, which brings the MOSFET to failure.
The extremely low reverse voltage occurring at these loads is not sufficient to guarantee the reverse recovery charge sweep out before turning off the MOSFET.