7 March 2023
ROHM’s SiC SBDs chosen by Murata for data-center power supply units
Japan’s ROHM says that its high-performance silicon carbide (SiC) Schottky barrier diodes (SBD) are being used by Murata Manufacturing Group company Murata Power Solutions to increase performance and reduce the size of power supply units (PSUs) for data-center applications. ROHM says that its SCS308AH SiC SBDs feature high surge resistance and short recovery time, enabling high-speed switching.
Murata’s D1U front-end AC–DC power supply series includes many active units such as the D1U54P-W-2000-12-HB3C and D1U54P-W-1200-12-HC4PC, highly efficient power-factor-corrected front-end power supplies that provide 12V main and 12V/3.3V standby output. Multiple units can share current and operate in parallel.
The power supplies support hot-plugging and are protected from fault conditions such as over-temperature, over-current and over-voltage. Also, the low-profile 1U package makes them suitable for delivering reliable, efficient power to servers, workstations, storage systems and other 12V distributed power systems while minimizing the number of required power modules.
“By moving to SiC devices, we are able to develop power supplies with higher efficiency and higher power density. We can push the switching frequency of SiC devices higher to reduce the volume of passive components and heatsinks,” remarks Dr Longcheng Tan, senior electrical engineer and project leader, Murata Power Solutions. “Murata Group has a special procurement department for evaluating different SiC device vendors and their products. ROHM was chosen, mainly because their products are reliable. Samples were also available for prototyping, and ROHM provides prompt support. Their performance of the SBDs is excellent, and we are now in mass production with the D1U power supplies. Murata is also using ROHM’s SiC MOSFETs in 3-phase inverter development projects, and the performance of those SiC MOSFETs is satisfying,” he adds.
“We are the leading company in SiC power semiconductors and have achieved a significant technological lead in this field along with the provision of power solutions combined with gate driver ICs,” claims Jay Barrus, president, ROHM Semiconductor USA LLC. “Together with Murata Power Solutions, we want to further improve the energy efficiency of power supply systems by using the full potential of SiC technology for industrial and data infrastructure.”
ROHM’s latest third generation of SiC SBDs, which have been adopted by Murata Power Solutions, offer greater surge current capability while further reducing what is claimed to be the industry’s smallest forward voltage of its second-generation SBDs. The total capacitive charge (Qc) of ROHM’s SiC SBDs is small, reducing switching loss while enabling high-speed switching operation. In addition, unlike silicon-based fast-recovery diodes where the trr (reverse recovery time) increases along with temperature, ROHM’s SiC devices maintain constant characteristics. Also, the firm says that its SiC SBDs allow manufacturers to reduce the size of industrial equipment and consumer electronics, making them suitable for use in power-factor correction (PFC) circuits and inverters.