Integrated circuit having current-sensing coil

An integrated circuit, comprising:

• a ferromagnetic structure over a substrate, the ferromagnetic structure having a first ferromagnetic portion extending along a first direction, and a second ferromagnetic portion extending along the first direction and being separated from the first ferromagnetic portion in a second direction different from the first direction;
• a first conductive path over the substrate, the first conductive path being adjacent to the first ferromagnetic portion and the second ferromagnetic portion and extends along the second direction, the first conductive path comprising:
• a first conductive line in a first interconnect layer under the ferromagnetic structure;
• a second conductive line in a second interconnect layer over the ferromagnetic structure;
• and
• a first via plug coplanar with the ferromagnetic structure, the first via plug electrically coupling the first conductive line in the first interconnect layer and the second conductive line in the second interconnect layer;
• a second conductive path over the substrate, the second conductive path being adjacent to the first conductive path, the first ferromagnetic portion and the second ferromagnetic portion, and extending along the second direction;
• a coil structure over the substrate, the coil structure being wrapped around the ferromagnetic structure;
• and
• a voltage sensing circuit electrically coupled with the coil structure and configured to measure a voltage level of an induced electrical potential of the coil structure.

A method of operating an integrated circuit, comprising:

• generating a time-varying magnetic field based on a time-varying current on a first conductive path of the integrated circuit or a second conductive path, the first conductive path and the second conductive path extending through an open portion of a ferromagnetic structure, the first conductive path comprises:
• a first conductive line in a first interconnect layer under the ferromagnetic structure;
• a second conductive line in a second interconnect layer over the ferromagnetic structure;
• and
• a via plug coplanar with the ferromagnetic structure, the via plug electrically connecting the first conductive line in the first interconnect layer and the second conductive line in the second interconnect layer;
• and
• directing a portion of the time-varying magnetic field to pass through a coil structure by the ferromagnetic structure of the integrated circuit.