Application Note Overview

High-voltage intermediate bus converters (HV IBCs) are becoming essential as AI datacenters shift toward 800 V power distribution and demand higher efficiency in increasingly compact systems. To meet these requirements, designers are turning to wide-band-gap semiconductor technologies capable of operating near 1 MHz. This application note compares three leading options—lateral GaN HEMTs, SiC MOSFETs, and SiC cascode JFETs—focusing on conduction losses, switching behavior, parasitic capacitances, and gate-drive requirements within resonant converter architectures.

Download this application note to see how each device technology performs under realistic high-frequency LLC converter conditions. While all three options deliver comparable overall system efficiency, the analysis highlights important design tradeoffs: GaN excels in low gate-charge losses, SiC MOSFETs incur higher auxiliary losses, and CJFETs offer a compelling cost advantage among other benefits.

The note also evaluates stacked, single-phase, and three-phase LLC topologies, showing how three-phase designs achieve key benefits for high-density power systems. All these insights form the basis for onsemi’s ongoing hardware validation efforts, guiding the development of future HV IBC solutions for modern datacenter power architectures.