A multi-die instrumentation approach for enhanced proximity magnetic field sensing in WBG power electronic applications

The enhanced switching performance of wide bandgap power devices enables several advantages, including reduced per-cycle switching loss, improved energy conversion efficiency, and increased power density. However, such fast power-chopping results in extremely high switching incidents that complicate instrumentation and compromise the integrity of measurement signals in power management systems. This work addresses the impact of capacitively coupled dv/dt on proximity magnetic field detectors, intended for current measurement at switching nodes of wide bandgap power electronics. The proposed solution employs a multi-die approach to eliminate the coupled transient noise during the early processing stage, maintaining the detection bandwidth, and substantially reducing downstream filtering requirements. A magnetoresistance-based prototype was developed to validate the proposed concept. During leg-current measurements in a half-bridge converter under high-dv/dt conditions of up to 10.55 V/ns, the prototype achieved an 8.78 dB improvement in SNR compared to conventional signal processing, resulting in higher waveform fidelity and improved signal integrity. • A novel multi-die detection approach is proposed, enhancing the immunity of the measured signal against coupled d v d t transients in the proximity of switching power planes. • A hierarchical differencing tree architecture is introduced, providing progressively deeper rejection of systematic d v d t mismatch at each additional tree level. • A generalized N = 2 n channel framework demonstrates that scaling the die count accumulates effective sensitivity by a factor of N , reducing the required per-channel analog gain and relaxing front-end gain-bandwidth requirements. • A TMR-based prototype validates the proposed concept in a wide bandgap converter environment, achieving an 8.78 dB SNR improvement under d v d t transients up to 10.55 V/ns.