Vishay Offers Designers Free Online MOSFET Thermal-Simulation ToolDecember 14, 2006 by Jeff Shepard
Vishay Intertechnology Inc. has made available a web-based tool that gives designers a detailed simulation of how Vishay Siliconix MOSFETs will perform thermally and be affected by adjacent components in a wide range of applications. Vishay's new ThermaSim is a free tool that helps designers speed time to market by allowing detailed thermal simulations to be performed before prototyping. ThermaSim is powered by Rebecca 3D software from Epsilon Ingenierie. Applicable to any power MOSFET application, ThermaSim will be especially useful in high-current, high-temperature applications such as automotive, fixed telecom, desktop and laptop computer, and industrial systems.
In a first for online MOSFET simulation, ThermaSim uses structurally detailed models of Vishay Siliconix power MOSFETs 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.
The tool is rich in features, and the setup is comprehensive. The designer constructs PCB size, layers, material, and copper spreading; sets pad size and solder quality; defines the heat sink size, material, and attachment methodology; and selects the power-dissipation profile, system temperature, air flow, and assembly orientation with respect to gravity to correctly account for the effect of convection. Designers also have a choice between steady-state and transient simulation.
Simulation results are emailed directly to the designer and can be downloaded into Microsoft Excel. Multiple results with varying product, package, or other input data can be merged within Excel to compare and examine trends. Thermal images are provided, and an MPEG video clip of the thermal image with transient simulation also is available. Simulations can be saved for modifications at a later date.