Wolfspeed, a Cree Company and a leader in silicon carbide (SiC) power products, has introduced a 1000V MOSFET (metal–oxide–semiconductor field-effect transistor) that enables a reduction in overall system cost, while improving system efficiency and decreasing system size. The new MOSFET, specially optimized for fast charging and industrial power supplies, enables a 30% reduction in component count while achieving more than 3x increase in power density and a 33% increase in output power.
Designers can reduce component count by moving from silicon-based, three-level topologies to simpler two-level topologies made possible by the 1000 Vds rating of the SiC MOSFET. The increase in output power in a reduced footprint is realized by the ultra-low output capacitance—as low as 60pF—which significantly lowers switching losses.
This device enables operations at higher switching frequencies, which shrinks the size of the resonant tank elements and decreases overall losses, thus reducing heatsink requirements. Wolfspeed has determined these proof-points by constructing a 20kW full-bridge resonant LLC converter and comparing it to a market-leading 15kW silicon system.
Wolfspeed offers a 20kW full-bridge resonant LLC converter reference design, listed as part number CRD-20DD09P-2. This fully assembled hardware set allows designers to quickly evaluate the new 1000V SiC MOSFET and demonstrate its faster switching capability, as well as the increased system power density the device enables.
The LLC converter’s reference design files, which include full schematics, bill of materials, simulation files, and detailed a user guide, can be found online. The full hardware is available for purchase on demand from Wolfspeed.
The new 1000V, 65mOhm MOSFET is available in a through-hole, 4L-TO247 package. Wolfspeed plans to release another 1000V MOSFET in a 4L-TO247 package at 120mOhm in the coming weeks. This package has a Kelvin-source connection that allows engineers to create designs that maximize the benefits of SiC’s superior speed and efficiency. The surface mount versions of these devices will be released later this year.
Supporting the widespread implementation of off-board charging stations, Wolfspeed’s technology enables smaller, more efficient charging systems that provide higher power charging at lower overall cost. This market requires high efficiency and wide output voltage range to address the various electric vehicle battery voltages being introduced by automotive suppliers.
Wolfspeed’s new 1000V SiC MOSFET offers system designers ultra-fast switching speeds with a fraction of a silicon MOSFET’s switching losses. The figure-of-merit delivered by this device is beyond the reach of any competing silicon-based MOSFET.—John Palmour, CTO of Wolfspeed
With the introduction of its 1000V SiC MOSFET, Wolfspeed leads the market with the industry’s most complete device portfolio. Wolfspeed was the first company to release a commercially qualified SiC MOSFET in 2011.