Vishay's ThermaSim is a free tool that helps designers speed time to market by allowing detailed thermal simulations to be performed before prototyping.

The tool is the first online MOSFET simulation that uses structurally detailed power MOSFET models created using finite element analysis (FEA) techniques to increase the simulation's accuracy.

Designers also may define other heat-dissipating components and simulate their effect on the MOSFET's thermal operation. Simulating these components ensures optimum device selection for application specifications and eliminates fallouts during thermal-performance line testing.

Applicable to any power MOSFET application, ThermaSim is especially useful in high-current, high-temperature applications such as automotive, fixed telecom, desktop and laptop computer, and industrial systems.

Vishay has enhanced ThermaSim through:

• Improved simulation accuracy:
• Component pads/footprints are separated from the component model
• Higher internal/external meshing resolution

New features include:

• Users can now define and evaluate impact of solder thickness (from 100 percent to 150 percent of the nominal thickness of 0.1 mm)
• Users can now define the thermal glue thickness between the component and a heat sink
•  Component model accounts for the air gap between the component and PCB surface where applicable
• Additional materials for PCBs, heat sinks, and the thermally conducting insulators

Improved simulation efficiency:

• Improved meshing methods
• Smaller PDF file sizes

Improved user friendliness:

• Features several completed examples that can be downloaded to user environment, modified, saved, and used

Offers user tips include:

• Parametric range limits and prevents wrong inputs
• Allows selection of steady-state, transient, or RC network simulations

Better selection/manipulation:

• Same component in different location on PCB
• Select/Edit internal PCB layers from side-view picture
• Select/Edit via zones from top-view picture
• Select/Edit solder thickness

Better documentation capabilities:

• An expandable summary tree of the entire simulation is provided just before running the simulation
• The filename and defined commenting text field are fed back on the simulation results

The enhanced version of ThermaSim is now available online for free at: www.vishay.com/mosfets/thermasim