ROHM’s New Class-Leading Low ON Resistance Nch MOSFETs: Delivering High Efficiency Operation in a Variety of Applications

40V-150V breakdown voltage lineup: ideal for motor drive and industrial power supplies

ROHM has developed Nch MOSFETs (40V/60V/80V/100V/150V) RS6xxxxBx / RH6xxxxBx series, 13 part numbers, suitable for applications operating on 24V/36V/48V power supplies such as base stations, servers, and motors for industrial and consumer equipment.

In recent years, worldwide power consumption has been on the rise – driving the need for industrial equipment such as servers and base stations along with various motors to become more efficient. In a number of these applications that utilize medium voltage MOSFETs, used in a variety of circuits, manufacturers are demanding even lower power losses. However, general MOSFETs are characterized by two main parameters leading to power losses: ON resistance (R_DS(on)), which is inversely proportional to chip size, and Gate-drain charge (Qgd) that increases proportionally with chip size, making it challenging to achieve both. ROHM has improved the trade-off between the two by adopting copper clip connections and improving the gate structure.

The new MOSFETs achieve an industry-leading R_DS(on) of 2.1mΩ – approx. 50% lower than conventional – by increasing device performance and adopting the HSOP8/HSMT8 package featuring low-resistance copper clip connections. What’s more, improving the element gate structure reduces Qgd, which is generally in a trade-off relationship with R_DS(on), by approx. 40% vs conventional products (comparing typical values for R_DS(on) and Qgd for 60V HSOP8 package products). These improvements reduce both switching and conduction losses, greatly contributing to higher application efficiency. As an example, when comparing the efficiency of a power supply evaluation board for industrial equipment, ROHM’s new products achieve an industry-leading efficiency of approx. 95% (peak) in the output current range during steady-state operation.

Going forward, ROHM will continue to develop MOSFETs with even lower R_DS(on) that reduce power consumption in a variety of applications, contributing to solving social issues such as environmental protection through energy conservation.

Product Lineup

Application Examples

◇ Power supplies for servers and communication base stations

◇ Motors for industrial and consumer products

Also suitable for a variety of power supply circuits and motor-equipped devices

Terminology

Nch MOSFET

A type of MOSFET that conducts when a positive voltage is applied to the Gate relative to the Source.

Nch MOSFETs are more widely distributed in the market today due to their lower ON resistance (R_DS(on)) over Pch variants, facilitating use in a broad range of circuits.

ON Resistance (R_DS(on))

The resistance value between the Drain and Source while the MOSFET is ON. The smaller this value is, the lower the (power) loss during conduction.

Qgd (Gate-Drain Charge)

The amount of charge when charging the capacitance between the Gate and Drain after the MOSFET turns ON. Lower values allow for faster switching that leads to lower switching loss (power loss).