Wide-bandgap power converters switch at kHz to several MHz, demanding current sensors that are simultaneously compact, linear, and immune to electromagnetic interference. Commercial shunts, Hall-effect (HE) ICs, magneto-resistive (MR), and core-based current transformers (CTs) satisfy only a subset of these requirements. This thesis introduces a hybrid sensing architecture that combines a PCB-embedded differential Rogowski coil for high-frequency detection with a tunneling magnetoresistance (TMR) sensor for DC-to-kHz detection. The complete design of the high bandwidth current sensor will be developed using an automated design tool based on user specifications. The MATLAB-based tool designs a Rogowski coil using analytic expressions, verifying parasitics with Ansys Q3D and OrCAD extraction. It pulls from a device database to select an MR that remains linear under the computed flux density, and employs a constrained nonlinear cost function to optimize all passive components in the differential amplifier and inverting integrator conditioning stages, forcing unity gain across the combined bandwidth while respecting realistic R-C limits. LTspice co-simulation of the synthesized stages provides pre-hardware validation. By collapsing electromagnetic design, device selection, and circuit optimization into a single script, the proposed tool reduces the design cycle time from weeks to minutes. It offers a reproducible path to high-bandwidth, non-invasive current sensing for power-electronic systems.
