Noise Reduction in Periodically Switching MOSFET Circuits Using Iteratively Found Synthesized Control Signals

In many modern power electronic systems, fast periodically switching semiconductors are utilized for system control and minimizing switching losses. The resulting steep switching waveforms may cause electromagnetic interference (EMI) that is mostly reduced with help of heavy passive filter circuits. One basic idea is to optimize EMC behavior and efficiency of power electronic devices by forming the switching waveforms with regard to steepness, overshoots, ringing and high frequency disturbances. Therefore, optimum control signals have to be found and synthesized. To do so, the nonlinear transmission behavior of semiconductor devices has to be considered. To start with, a basic MOSFET test circuit is regarded in this work. With help of an iterative search algorithm, a control signal is found that fits the MOSFET’s output signal to a desired waveform that optimizes EMI and minimizes switching losses. The capability of this method is shown by simulations and measurements.