A Comparison Between Screen-Return and Trace-Return PCB Rogowski Coils for SiC Power Modules

PCB Rogowski Coils (PCBRCs) are becoming increasingly popular as a switch current sensor for SiC Power modules in applications such as overcurrent protection, peak current mode control, and junction temperature estimation. In order to increase the PCBRC's noise immunity in the presence of electromagnetic interference, a compensation structure is necessary. This paper compares a screen-return and a trace-return PCBRC compensation structure. Trade-offs in sensitivity and bandwidth are discussed when fabricating both designs on a four-layer PCB stack-up. The noise immunity of both the compensation structures is evaluated with the aid of theoretical models and experimental data.