This technical article explains important parameters of modern power MOSFET devices, including power dissipation and its linear derating factor, silicon limited drain current, and pulsed drain current. It explains what these parameters are and how they can be calculated, serving as a useful tool for customers to understand and facilitate reading of a power MOSFET datasheet.
This document serves as a technical guide for understanding Safe Operating Area (SOA) limits in power MOSFETs. It details the Forward Biased Safe Operating Area (FBSOA) and Reverse Biased Safe Operating Area (RBSOA), explaining how parameters like maximum drain current and breakdown voltage define these safety zones.
The maximum junction temperature is typically 150°C or 175°C for automotive devices.
The device limited current equals the silicon limited current when the case temperature overcomes 110°C.
The example calculation uses a junction to case thermal resistance of 0.5°C/W.