Abstract-A new analytical model is presented in this work to predict power losses and waveforms of high-voltage silicon SuperJunction (SJ) MOSFET during hardswitching operation. This model depends on datasheet parameters of the semiconductors, as well as, the parasitics obtained from the printed circuit board characterization. It is important to note that it also includes original features accounting for strong capacitive non-linearities and displacement currents. Moreover, these features demand unusual extraction of electrical characteristics from regular datasheets. A detailed analysis on how to obtain this electrical characteristics is included in this work.Finally, the high accuracy of the model is validated with experimental measurements in a double-pulse buck converter setup by using commercial SJ MOSFET, as well as, advanced device prototypes under development.

For determining the dynamic ON-resistance R dyn,on of a power transistor, the voltage and current waveforms have to be measured during the switching operation. The novel heterostructure wide-bandgap (e.g., AlGaN/GaN) transistors inherently suffer from the current collapse phenomenon, causing the dynamic ON-resistance to be different from the static. Measuring voltage waveforms using an oscilloscope distorts the characteristics of an amplifier inside the oscilloscope when the range of the measurement channel is not set wide enough to measure both ON-state and OFF-state voltage levels, resulting in failure to accurately measure the voltage waveforms. A novel voltage clamp circuit improving the accuracy of the transistor's ON-state voltage measurement is presented. Unlike the traditional clamping circuit, the presented voltage clamp circuit does not introduce delay caused by RC time constants, keeping the voltage waveform clear, even during state transitions of the device under test. The performance of the presented circuit is illustrated by measurements on a 2-MHz inverted buck converter.

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A multi-objective design procedure is applied to the design of a close-coupled inductor for a three-phase interleaved 140kW DC-DC converter. For the multi-objective optimization, a genetic algorithm is used in combination with a detailed physical model of the inductive component. From the solution of the optimization, important conclusions about the advantages and disadvantages of using close-coupled inductors compared to separate inductors can be drawn.