Gate charge and switching speed — the 5.5 nC advantage
The BSZ42DN25NS3GATMA1: Total gate charge of 5.5 nC at 10 V reduces driver dissipation. Input capacitance is 430 pF at 100 V drain-source — a low value that further reduces the drive current needed per switching cycle. The combination of low Ciss and low Qg makes this part a candidate for GaN-driver replacement in legacy 250 V rails where the switching frequency is being pushed up.
Thermal and package reality for the layout engineer
The 8-PowerTDFN package dissipates 33.8 W at the case. The 4 V maximum gate threshold at 13 µA drain current requires a 10 V gate drive.
The OptiMOS series is Infineon's mainstream high-voltage trench platform, so PCN risk is low and second-source options exist in the same voltage class.
