Core-based current sensors with integrated compensation coils

A method of making a closed-loop current sensor, the method comprising:

• providing a magnetic core having first and second ends and an aperture receiving a first busbar and a second busbar configured to conduct input and output current in opposite directions, wherein the magnetic core is configured so that the first and second ends are separated by a gap;
• providing a magnetic field sensor disposed in an integrated circuit (IC) and supported by a substrate, wherein the magnetic field sensor is configured to receive magnetic flux from the gap, wherein the magnetic field sensor is configured to measure a difference in magnetic fluxes of the first busbar and the second busbar;
• and
• providing a coil integrated with the substrate and coupled to the IC, wherein the coil is configured to provide negative magnetic feedback based on a leakage current for closed-loop compensation.

A closed-loop current sensor comprising:

• a magnetic core having first and second ends and an aperture receiving one or more conductors, wherein the magnetic core is configured so that the first and second ends are separated by a gap;
• a magnetic field sensor disposed in an integrated circuit (IC) and supported by a printed circuit board (PCB), wherein the magnetic field sensor is configured to receive magnetic flux from the gap, wherein the IC is configured to measure AC current in the one or more conductors;
• and
• a coil integrated with the PCB and coupled to the IC, wherein the coil is configured to provide negative magnetic feedback based on a leakage current for closed-loop compensation.