EL SEGUNDO, Calif. — International
Rectifier, IR® 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
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
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
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).
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