Apparatus and method for a current sensor

A method of sensing a flow of current in a conductor comprising:

• generating an output voltage representative of the current flowing in the conductor by magnetically coupling, at a sensing area, to a first magnetic field generated by the current flowing in the conductor, wherein magnetically coupling to the first magnetic field includes presenting the first magnetic field to a coil of electrically conductive material disposed adjacent the conductor;
• shielding the sensing area from an external magnetic field including generating a second magnetic field that opposes the external magnetic field so that the output voltage generated by magnetically coupling to the first magnetic field is substantially free of influence from the external magnetic field;
• shielding the sensing area from an electric field generated by the current flowing in the conductor by coupling the electric field to a conductive lead that is disposed adjacent to both the conductor and the coil of electrically conductive material and connected to ground potential;
• and
• preventing production of a shield-generated magnetic field, resulting from the flow of current in the conductor, that opposes the first magnetic field generated by the flow of current in the conductor.

A current sensor comprising:

• first means for magnetically coupling, at a sensing area proximate to a conductor, to a first magnetic field generated by a current flow in the conductor, the first means having an output representative of the current flow;
• second means for generating a second magnetic field that opposes an external magnetic field to shield the sensing area from the external magnetic field so that the output of the first means is substantially free of influence from the external magnetic field;
• third means for shielding the sensing area from the second means to prevent production of a shield generated magnetic field, resulting from the flow of current in the conductor, that opposes the first magnetic field generated by the flow of current in the conductor so that the output of the first means is substantially free of influence from effects of the second means;
• and
• a fourth means for capacitively shielding the sensing area to prevent an electric field generated by the flow of current in the conductor from being capacitively coupled to the sense element, wherein the fourth means includes a conductive lead configured to be disposed adjacent to both the sensing area and the conductor, the conductive lead including a free first end and a second end configured for a connection to a ground potential.