DirectFET®; MOSFET High Frequency Operation

Package Impedance vs. Frequency

DirectFET MOSFET Package Benefits
Frequency effect over package impedance: Skin Effect
Skin effect & skin depth
At high frequencies current is confined to the perimeter of solid conductors. This phenomenon is often referred to as the skin effect. Skin depth

Theoretical modeling results under AC conditions
Developed MathCAD model using Maxwell’s equations. For a rectangular bar structure Rac/Rdc is a function of width over skin depth.

Apply the scale factor Rac/Rdc to each element in model at different values of frequency to predict R versus frequency behaviour…


Gauge R&R results: sigma = 32mOhms


Note: DirectFET device includes copper slug. All packages include inductance of tracks under package.

IR’s proprietary DirectFET®; technology is covered by US Patent 6,624,522 and other US and foreign pending patent applications.