ROHM Develops Class-Leading* Low ON-Resistance, High-Power MOSFETs for High-Performance Enterprise and AI Servers

　　ROHM has developed N-channel power MOSFETs featuring industry-leading* low ON-resistance and wide SOA capability. They are designed for power supplies inside high-performance enterprise and AI servers.

　　The advancement of high-level data processing technologies and the acceleration of digital transformation have increased the demand for data center servers. At the same time, the number of servers equipped with advanced computing capabilities for AI processing is on the rise and is expected to continue to grow. These servers operate 24 hours a day, 7 days a week – ensuring continuous operation. As a result, conduction losses caused by the ON-resistance of multiple MOSFETs in the power block have a significant impact on system performance and energy efficiency. This becomes particularly evident in AC-DC conversion circuits, where conduction losses make up a substantial portion of total power loss – driving the need for low ON-resistance MOSFETs.

　　Additionally, servers equipped with a standard hot-swap function, which allow for the replacement and maintenance of internal boards and storage devices while powered ON, experience a high inrush current during component exchanges. Therefore, to protect server components and MOSFETs from damage, a wide Safe Operating Area (SOA) tolerance is essential.

　　To address these challenges, ROHM has developed its new DFN5060-8S package that supports the packaging of a larger die compared to conventional designs, resulting in a lineup of power MOSFETs that achieve industry-leading* low ON-resistance along with wide SOA capability. These new products significantly contribute to improving efficiency and enhancing reliability in server power circuits.

　　The new lineup includes three products. The RS7E200BG (30V) is optimized for both secondary-side AC-DC conversion circuits and hot-swap controller (HSC) circuits in 12V power supplies used in high-performance enterprise servers. The RS7N200BH (80V) and RS7N160BH (80V) are ideal for secondary AC-DC conversion circuits in 48V AI server power supplies.

　　All three models feature the newly developed DFN5060-8S package (5.0mm × 6.0mm). The package increases the internal die size area by approximately 65% compared to the conventional HSOP8 package (5.0mm × 6.0mm). As a result, the RS7E200BG (30V) and RS7N200BH (80V) achieve ON-resistances of 0.53mΩ and 1.7mΩ (at VGS = 10V), respectively – both of which rank among the best in the industry in the 5.0mm × 6.0mm class, significantly contributing to higher efficiency in server power circuits.

　　Moreover, ROHM has optimized the internal clip design to enhance heat dissipation, further improving SOA tolerance, which contributes to ensuring application reliability. Notably, the RS7E200BG (30V) achieves an SOA tolerance of over 70A at a pulse width of 1ms and VDS = 12V, which is twice that of the conventional HSOP8 package MOSFETs under the same conditions, ensuring industry-leading SOA performance in a 5.0mm × 6.0mm footprint.

　　Going forward, ROHM plans to gradually begin mass production of power MOSFETs compatible with hot-swap controller circuits for AI servers in 2025, continuing to expand its lineup that contributes to greater efficiency and reliability across a wide range of applications.

　　Product Lineup

　　EcoMOS™ Brand

　　EcoMOS™ is ROHM's brand of silicon power MOSFETs designed for energy-efficient applications in the power device sector.

　　Widely utilized in applications such as home appliances, industrial equipment, and automotive systems, EcoMOS™ provides a diverse lineup that enables product selection based on key parameters such as noise performance and switching characteristics to meet specific requirements.

　　EcoMOS™ is a trademark or registered trademark of ROHM Co., Ltd.

　　Application Examples

　　・AC-DC conversion and HSC circuits for 12V high-performance enterprise server power supplies

　　・AC-DC conversion circuits for 48V AI server power supplies

　　・48V industrial equipment power supplies (i.e. fan motors)

　　Terminology

　　Low ON-Resistance (RDS(on))

　　The resistance value between the Drain and Source of a MOSFET during operation. A smaller RDS(on) results in lower power loss during operation.

　　SOA (Safe Operating Area) Tolerance

　　The range of voltage and current within which a device can operate safely without damage. Exceeding this range can lead to thermal runaway or device failure, making SOA tolerance a critical factor, especially in applications prone to inrush current or overcurrent.

　　Power MOSFET

　　A type of MOSFET used for power conversion and switching applications. N-channel MOSFETs are the mainstream choice, as they become conductive when a positive voltage is applied to the gate relative to the source, offering lower ON-resistance and higher efficiency than P-channel variants. Due to their low loss and high-speed switching capabilities, power MOSFETs are widely used in power circuits, motor drive circuits, and inverters.

　　Hot-Swap Controller (HSC)

　　A specialized integrated circuit (IC) that enables hot-swap functionality, allowing components to be inserted or removed while the power supply system remains active. It plays a crucial role in managing inrush current that occurs during component insertion, protecting both the system and connected components from damage.

　　Inrush Current

　　A sudden surge of current that momentarily exceeds the rated value when an electronic device is powered ON. Proper control of this current reduces stress on power circuit components, helping to prevent device failure and stabilize the system.