A practical look at MOSFET current ratings

System designers are often faced with the task of selecting the most suitable power device from a wide array of products from different manufacturers with very similar ratings. While a detailed parameter-by-parameter comparison is technically the most correct way of selection, it is not the most practical, and therefore designers resort to making their first cut based on three or four simple parameters such as package, voltage and current ratings, and R_ds(on).

This article takes a close and practical look at the current rating, in terms of thermal modeling, thermal resistance, heat sinks, and packaging. For purposes of illustration, it is focused on MOSFETs in low- and medium-power packages, but the considerations can be applied to other technologies as well.

To read the article as a pdf (no registration required), click here.

About the author

Sanjay Havanur is currently the Principal Applications Engineer at Alpha & Omega Semiconductor, Inc. ( Sunnyvale, CA)After getting his Master's Degree in Power Electronics and Drives at the Indian Institute of Technology, Mumbai in 1983, he has gained extensive experience in the field of power electronics, having worked in design and applications both in India and USA. He has published papers and application notes in technical journals, and holds several patents relating to high frequency power conversion. Sanjay Havanur's current interests include novel and efficient power conversion topologies, energy harvesting techniques and solar power.

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