This application note introduces UniFET™ II, a new power MOSFET optimized for resonant converters, which provides better reliability and higher efficiency in resonant converters with its robust body diode characteristics
Resonant converters are popular topologies that utilize the body diode of MOSFETs for Zero-Voltage Switching (ZVS). However, failures can occur due to slow reverse recovery or breakdown dv/dt under overload and short-circuit conditions. The UniFET II power MOSFET is designed specifically to address these failure mechanisms.
Failures are caused by parasitic BJT turn-on due to high current and temperature, triggered by body diode reverse recovery or breakdown dv/dt.
The UniFET II has improved body diode ruggedness and output stored energy in Coss, while minimizing negative effects like increased on-resistance.