400 V SiC MOSFET Technology Empowering Innovative Three-Level Power Supplies for AI Servers

The introduction of 400 V CoolSiC™ MOSFET technology bridges the voltage range gap between 200 V medium-voltage MOSFETs and 600 V super-junction MOSFETs. This technology is characterized by low switching losses and low on-state resistance, making it suitable for innovative 3-level topologies. The technology concept is presented and important device properties are discussed. The combination of the novel 400 V SiC MOSFET device technology with a multi-level topology enables a 12 kW AC/DC single-phase power supply to meet the growing power demands of data centres and provides high power density (100 W/in<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>) and efficiency (η > 97.5%). To keep the load transients of AI chips away from the AC line, a novel control concept involving a power-pulsation buffer circuit is introduced, which acts as an active filter and also provides full control of re-rush currents after line-cycle drop-outs.