Losses in high-power bipolar transistors

The calculation of power losses in high-power bipolar transistors is examined for several of the commonly encountered types of power circuits. The magnitude of switching and conduction losses is dependent on the type of circuit in which they are used, the type of load, switching frequency, and characteristics of the transistor itself. Curves, based on computer simulation and mathematical analysis, are presented to aid in the calculation of these losses. Parameters taken into account are dynamic saturation voltage, load power factor, effect of snubbers, and recovery characteristics of circuit associated diodes.