Automatic Loss Measurement System for MHz Magnetics Using High-Frequency Conditioning Circuits

Accurate loss data is necessary for effective magnetic component design and evaluation - both of complete components and of core materials. While automated systems are available for core loss characterization at sub-MHz frequencies, only labor-intensive resonance-based measuring methods are available at higher frequencies. These typically rely on users to extract features from distorted waveforms and tune for resonance. In this paper, an integrated automated measurement system is proposed to eliminate dependence on external measurement equipment (such as oscilloscopes) and manual tuning, thus measuring core loss or component loss in MHz magnetic components within seconds. The system uses high-frequency conditioning circuits to extract the magnitude and phase information of signals of interest without high-speed ADCs, FFT computations, or external measurement equipment. An embedded microcontroller executes real-time algorithms to reach resonant points and collects core-loss-related data. The automatic test results on MHz magnetic materials align with datasheets and expand the core loss characterization range, thus verifying the feasibility and effectiveness of the proposed system.