Embedded toroidal magnetic coupling probe in multi-layer PCBs for current measurement

The importance of current detection has been highlighted with the introduction of 3D-IC, in order to ensure the safe and reliable operation of analog circuits in mixed-signal systems. In this paper, we propose toroidal current probe embedded in multi-layer printed circuit boards (PCBs) for current detection. Current is magnetically coupled to the proposed current probe and the transfer impedance between the port of injected current and the proposed current probe is used for the analysis of current coupling and current reconstruction. Through time- and frequency-domain experimental measurements with test vehicles on multilayer PCBs, we verified that the proposed current probe can accurately detect current signals. The proposed current probe does not influence the original current path, yet achieves high accuracy with a compact size by using a toroidal array of vias that surrounds the current path.