Understanding the Data Sheet: PowerMOS:Allmanufacturers of powerMOSFETs provide a data sheet for every type produced. The purpose of the data sheet is primarily to give an indication as to the capabilities of a particular product. It is also useful for the purpose of selecting device equivalents between different manufacturers. In some cases however data on a number of parameters may be quoted under subtly different conditions by different manufacturers, particularly on second order parameters such as switching times. In addition the information contained within the data sheet does not always appear relevant for the application. Using data sheets and selecting device equivalents therefore requires caution and an understanding of exactly what the data means and how it can be interpreted. Throughout this chapter the BUK553-100A is used as an example, this device is a 100 V logic level MOSFET.