Performing Safe Operating Area Analysis on MOSFETs and Other Switching Devices with an Oscilloscope
Safe operating area (SOA) is commonly specified in datasheets for MOSFETs, IGBTs and other switching devices. It's a useful, graphical representation of the current, voltage, and power limits for a device. This application note explains how to use an oscilloscope to compare the in-circuit operation of a MOSFET to it's specified safe operating area, to determine if it is going outside its specified range. This measurement is especially important to those designing switch mode power supplies, who need to measure switch performance under many operating conditions.