Performance analysis of commercial MOSFET packages in Class E converter operating at 2.56 MHz

Abstract

Wide bandgap (WBG) power electronic devices realized using silicon carbide(SiC) and gallium nitride (GaN) are increasingly replacing their silicon(Si) counterparts in power electronics applications. The obvious advantages of these devices with their higher switching speeds, lower on state resistance and high temperature operation over Si devices have aided in the paradigm shift towards wide bandgap devices. The low gate charge requirements of SiC MOSFETs enables use of these devices in radio frequency (RF) converters using resonant topologies operating at MHz frequency range. The RF converters employed in various industrial applications are currently realized with vacuum tubes. Replacing vacuum tubes with solid state devices provides greater reliability. This requires power switches transferring high power at high switching speeds. Wide bandgap devices operating at these specifications are not commercially available and power modules have to be custom designed for these applications. This work demonstrates performance of various commercial MOSFET packages at frequency of 2.56 MHz. Commercial SiC MOSFETs in TO-247 and D2Pak packs are tested in Class E resonant converter operating at 2.56 MHz and compared with DE-275 Radio Frequency (RF) package performance under same operating conditions. Design considerations deduced from results can then be used in design of custom low voltage SiC RF modules and eventually can be used in the design of high voltage modules.