Effect of IGBT switching dynamics on loss calculations in high speed applications

The switching and conduction loss in bipolar devices are dependent on the s witching intervals, especially when these intervals become small enough to prevent the device from reaching steady-state conditions. This behavior is quite pronounced for non-punch-through IGBT's, and is found to drastically decrease the overall switching loss of these devices in high frequency appl ications relative to values projected from conventional approaches. It also results in an unexpected dependence of net losses on duty cycle. The reaso ns behind this behavior are examined, and its implications for semiconducto r loss calculations are discussed.