Compensated Power Sensor for Semiconductor Switching Loss Measurement

Quantifying switching losses is crucial for designing high efficiency power converters. However, switching energy data is limited, partially due to limitations of a standard double-pulse test (DPT). This paper presents a simple calorimetric fixture operating on the principle of heat flux balance, capable of separating turn-on and turn-off energies at various junction temperatures. It requires minimal calibration and is significantly faster than conventional calorimetric methods. Contrary to DPT-based data, a complete loss map of a transistor can be extracted, including hard- and soft-switching regimes. The method does not modify the commutation loop and can be operated in situ in the designed converter, measuring switching energies that include effects of actual circuit parasitics and component parameters.