Power MOSFETs Reduce Thermal and Electrical Resistance

Jan 24, 2007 11:42 AM

Vishay Intertechnology’s n-channel device additions to its PolarPAK family of power MOSFETs feature double-sided cooling. On-resistance for the 20-V SiE810DF and SiE808DF, 30-V SiE806DF, and 40-V SiE812DF ranges from 1.4 mΩ to 2.6 mΩ.

These PolarPAK devices share the same footprint area as the standard SO-8, yet are twice as thin with a height profile of 0.8 mm. With on-resistance-times-gate-charge figures of merit (FOMs) of 127.5 and 135.2, respectively, the 30-V and 40-V devices offer nearly the same FOM for synchronous rectification applications while allowing the choice of the higher rating for applications that need the additional headroom provided by the 40-V device.

These improved specifications translate into lower conduction and switching losses that reduce power consumption in end systems. The dual heat-dissipation paths provided by PolarPAK's double-sided cooling construction allow high current densities in systems with forced air cooling, enabling more compact designs and/or the ability to reduce the number of paralleled MOSFETs.

For applications in which minimizing switching losses is more critical than low conduction losses, Vishay is also releasing two PolarPAK devices with somewhat higher on-resistance. At a 10-V gate drive, the 30-V SiE830DF is rated for 4.2 mΩ, and the 40-V SiE832DF is rated at 5.5 mΩ.

The devices have a fixed footprint and pad layout, independent of die size across the range of the family, eliminating the need for redesign when newer generations of silicon are introduced. Their standard leadframe and plastic-encapsulation construction provide good die protection.

Samples and production quantities of the new PolarPAK power MOSFETs are available now. Pricing in 100,000-piece quantities is $1.50 per piece.