In the 1980’s the selection of MOSFET devices was limited, if you could find one meeting the peak voltage in your application with de-rating, the selection was simple&#151Buy It.

Today the variety has expanded exponentially. Each supplier’s method of specifying parameters can be done differently adding confusion to the selection process. This paper will discuss alternate selection methods and provide insight into the how secondary parameters affect the in circuit performance. Focusing upon the latest characterization techniques, this selection process will include discussions into the difference between data sheet specifications and actual in circuit performance.