As the power demand for AI processors increases, server power supplies need to provide more and more power up to the specified dimensions of the server rack. That's because the energy demand for GPUs has skyrocketed, with experts predicting that by the end of 2030, power consumption could reach 2kw or more per chip.
According to Infineon, the demand for energy and the needs of market user groups will drive the development of SiC MOSFETs to voltages below 650 V. The company is now introducing a new 400V family of CoolSiC MOSFETs, which is an upgraded version of the second-generation (G2) CoolSiC technology introduced in March this year. SiC MOSFETs have lower losses at switching, which makes them more efficient than traditional silicon-based MOSFETs in power conversion applications.
The new MOSFET portfolio has been developed specifically for the AC/DC phase of AI servers and complements Infineon's PSU roadmap announced in May this year. In addition, these devices are suitable for solar and energy storage systems (ESS), inverter motor controllers, industrial and auxiliary power supplies (SMPS), and solid-state circuit breakers for residential buildings.
Figure: Infineon's CoolSiC 400V MOSFETs
"Infineon offers a broad portfolio of high-performance MOSFETs and GaN transistors to meet the demanding design and space requirements of AI server power supplies," said an official from Infineon, "We are committed to supporting our customers with advanced products such as the CoolSiC MOSFET 400V G2 to achieve the highest energy efficiency in advanced AI applications." Due to the high efficiency and high-temperature operation, SiC MOSFETs can be designed to be smaller, helping to reduce the overall size of the system.
Compared to existing 650V SiC and silicon MOSFETs, the new series features ultra-low conduction and switching losses. The AC/DC stage of the AI server PSU is implemented with multi-stage PFC, which can reach a power density of more than 100W/in3 and an efficiency of 99.5%. This is an improvement of 0.3 percentage points compared to solutions using 650V SiC MOSFETs. In addition, by implementing CoolGaN transistors in the DC/DC stage, the system solution for AI server PSUs is complete. With this combination of high-performance MOSFETs and transistors, the power supply can deliver more than 8kW of power and more than 3x higher power density than existing solutions.
The new MOSFET portfolio consists of a total of 10 products: five R DS(on) classes, from 11mΩ to 45mΩ, in Kelvin source TOLL and D2 PAK-7 packages, and . XT package interconnect technology. The drain-source breakdown voltage of 400V at T vj = 25°C makes it suitable for use in 2- and 3-level converters as well as synchronous rectification. These components are highly robust under harsh switching conditions and are 100% avalanche tested. The highly robust CoolSiC technology is combined with . XT interconnect technology combines to enable devices to cope with power spikes and transients caused by sudden changes in the power needs of AI processors. Both the connection technology and the low and positive R DS(on) temperature coefficient enable excellent performance at high junction temperatures. Engineering samples of the CoolSiC MOSFET 400V portfolio are available now, with volume production starting in October.
