Measurement of the BJT activation current during the reverse recovery of power MOSFET's drain-source diode

A new and simple method to measure the activation current of the parasitic BJT in the drain-source MOSFET's diode is presented. Based on the evaluation of the stored charge at supply voltages lower than the maximum reverse voltage of the device, accurate and safe measurements have been performed at forward current levels up to the MOSFET's maximum current rating.