Optimizing MOSFET Selection for the 48 V Hybrid Mobility Market

Abstract:
This study assesses the performance of regular trench and split-gate MOSFET technologies in 48 V mobility systems, focusing on electromagnetic compatibility (EMC), switching losses, and efficiency. Double-pulse testing and EMC measurements are used for device-level characterization to measure oscillatory behavior, dynamic losses, and conduction losses. Three representative 48 V systems: a 48 V brushless DC motor drive, a 48–5 V isolated DC–DC converter, and a 48–12 V non-isolated buck converter are subjected to application-level testing. Logic level 3×3 mm² and standard level 5×6 mm² package sizes are benchmarked for efficiency and thermal performance in order to evaluate the trade-offs in package area and technology. The findings show that split-gate devices have a favorable cost-per-resistance figure of merit when compared to trench devices, while also achieving up to 20% lower switching losses, improved damping factors, and reduced EMC emissions. While trench devices are still used in legacy designs, these findings demonstrate the suitability of split-gate MOSFETs for high-frequency, EMC-sensitive applications.