Assessment of MOSFET switching losses based on junction temperature. Comparison in an LLC converter between TO-247 and ACEPACK SMIT using MDmesh DM6 technology.

The present work aims to implement a calorimetric method to measure the power dissipated during MOSFET switching in a high efficiency LLC resonant converter. The power dissipated from switching can significantly impact the total power dissipated by the device and consequent efficiency, so correct quantification is fundamental for optimizing the devices and increasing the efficiency of the converters. In LLC converters, this type of dissipated power cannot be measured with standard methods such as measurement with oscilloscopes, as some of the energy that is recovered and not dissipated. The calorimetric method requires reasonably accurate measurement of thermal resistance and the temperature of the die. To do this, two different methods have been used: the first measures the temperature on a TO-247 MOSFET with an IR thermal camera, the second uses an ACEPACK(TM) SMIT package module that incorporates a complete half-bridge and an NTC thermistor for reading the temperature.