EL SEGUNDO, Calif. — October 2005 — International Rectifier, IR® (NYSE: IRF), a world leader in power management technology, today introduced two DirectFET® power MOSFETs that reduce system-level power loss as much as 10% versus “enhanced SO-8” devices in medium power 200W DC-DC bus converter applications commonly found in networking and communications systems. The low combined on-state resistance and gate charge makes the new IRF6668 80V and IRF6662 100V DirectFET MOSFETs ideal primary-side power switches for high efficiency isolated DC-DC bus converters.

“Isolated DC-DC bus converters power today’s ASICs, NPUs and FPGAs in advanced networking and communications systems. The IRF6668 and IRF6662 can be used with IR’s low voltage DirectFET MOSFETs and DC bus converter control ICs to create a complete and optimized chip set solution for medium-power isolated bus converters,” said Carl Smith, Marketing Manager for Networking and Telecommunication Products at International Rectifier.

When the IRF6662 or IRF6668 are used on the primary side of an unregulated 48V input, 8V output, 200W isolated converter the power density of 97W/in2 can be increased an additional 15%. This is enabled by taking advantage of the dual-sided cooling capability of the DirectFET MOSFET packaging technology with the addition of a heat sink.

The 100V IRF6662 has a 4% reduction in device on-resistance compared to competing enhanced SO-8 MOSFETs and a 30% better performance figure-of-merit for combined on-state resistance and gate charge compared to competing enhanced SO-8 devicesin 36-75V input, 8V output, 200W, 220kHz half-bridge DC bus converter.

The 80V IRF6668 has 10% better on-state resistance and 30% better total gate charge, resulting in a 40% better performance figure-of-merit for combined on-state resistance and gate charge compared to competing enhanced SO-8 MOSFETs, enablingup to 10% additional output current in 48V input, 8V output, 200W, 220kHz half-bridge DC bus converter.

The new DirectFET MOSFETs can be used in either half-bridge DC bus topologies with the IR2085S or in full-bridge DC bus topologies with IR2086S, coupled with secondary-side low voltage DirectFET MOSFETs like the IRF6635 for a complete, high efficiency solution.

Patented DirectFET® Packaging Technology

International Rectifier's patented DirectFET MOSFET packages present a whole new set of design advantages not previously delivered by standard plastic discrete packages. Their metal can construction enables dual-side cooling that effectively doubles the current handling capacity of high frequency DC-DC buck converters powering advanced microprocessors. In addition, devices in the DirectFET package are compliant with the Restriction of Hazardous Substances Directive (RoHS).

Part Number	Package	VDSS	RDS(on) max. @ Vgs=10V	Qg Typical	Qgd Typical
IRF6668	DirectFET MZ	80V	15mOhm	22nC	7.8nC
IRF6662	DirectFET MZ	100V	22mOhm	22nC	6.8nC

Design Tools and Application Notes
AN-1035 – Board Mounting Guidelines for DirectFET® MOSFETs
AN-1050 – Materials & Practices for DirectFET® MOSFETs
AN-1059 – Thermal modeling and Characterization for DirectFET® MOSFETs

The DirectFET® Home Page gives designers a deeper understanding of how to use the unique advantages of DirectFET devices and how they increase electrical and thermal performance.

Availability and Pricing

The 100V IRF6662 and the 80V IRF6668 DirectFET® MOSFETs are available immediately. Pricing is US $0.99 each for either device, both in 10,000-unit quantities. Prices are subject to change.