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 growing. These servers operate 24/7 to ensure 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 is particularly evident in AC-DC conversion circuits, where conduction losses constitute a substantial portion of the total power loss, driving the need for low on-resistance MOSFETs.
Furthermore, servers equipped with a standard hot-swap feature, which allows for the replacement and maintenance of internal boards and storage devices while powered on, experience high inrush currents during component swaps. Therefore, a wide safe operating area (SOA) tolerance is essential to protect server components and MOSFETs from potential damage.
To address these challenges, ROHM has developed its new DFN5060-8S package, which allows for the packaging of a larger chip compared to conventional designs. This results in a range of power MOSFETs that achieve industry-leading* low on-resistance and high SOA capability. These new products significantly contribute to improving the efficiency and increasing the reliability of server power circuits.
The new product range includes three products. The RS7E200BG (30 V) is optimized for both secondary-side AC-DC conversion circuits and hot-swappable controller (HSC) circuits in 12 V power supplies used in high-performance enterprise servers. The RS7N200BH (80 V) and RS7N160BH (80 V) are ideal for secondary AC-DC conversion circuits in 48 V AI server power supplies.
All three models incorporate the new DFN5060-8S package (5.0 mm × 6.0 mm). This package increases the internal chip area by approximately 65% compared to the conventional HSOP8 package (5.0 mm × 6.0 mm). As a result, the RS7E200BG (30 V) and RS7N200BH (80 V) achieve on-resistances of 0.53 mΩ and 1.7 mΩ (at VGS = 10 V), respectively—both among the best in the industry for the 5.0 mm × 6.0 mm class—significantly contributing to increased efficiency in server power supply circuits.
Furthermore, ROHM has optimized the internal clip design to improve heat dissipation, further enhancing SOA tolerance and contributing to application reliability. Specifically, the RS7E200BG (30 V) achieves an SOA tolerance of over 70 A with a 1 ms pulse width and VDS = 12 V, twice that of conventional HSOP8 MOSFETs under the same conditions, ensuring industry-leading SOA performance in a 5.0 mm × 6.0 mm form factor.
Looking ahead, ROHM plans to gradually begin mass production of power MOSFETs compatible with hot-swappable controller circuits for AI servers in 2025, thereby expanding its range that contributes to greater efficiency and reliability across a wide range of applications.
Product range
EcoMOS™
is ROHM's brand of silicon power MOSFETs designed for energy-efficient power device applications.
Widely used in applications such as household appliances, industrial equipment, and automotive systems, EcoMOS™ offers a diverse range that allows product selection based on key parameters such as acoustic performance and switching characteristics to meet specific requirements. EcoMOS
™ is a trademark or registered trademark of ROHM Co., Ltd.
Application examples
AC-DC conversion circuits and HSC circuits for 12V power supplies for high-performance enterprise servers.
AC-DC conversion circuits for 48V AI server power supplies.
48V power supplies for industrial equipment (e.g., fan motors).
