| CPC G01R 15/205 (2013.01) [G01R 33/0005 (2013.01); G01R 33/098 (2013.01)] | 9 Claims |
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1. Magnetic current sensor, comprising:
a sensor bridge circuit comprising:
a first half-bridge comprising two series-connected and diagonally opposed tunnel magnetoresistive (TMR) sensor elements; and
a second half-bridge comprising two series-connected and diagonally opposed TMR sensor elements,
each TMR sensor element comprising a tunnel barrier layer, a reference layer having a pinned reference magnetization and a sense layer having a sense magnetization that can be freely oriented, the TMR sensor elements having their reference magnetization oriented substantially in the same direction; and
a field line configured to pass a field current generating a magnetic field such that the sense magnetization of the diagonally opposed TMR sensor elements of the first half-bridge is oriented along the direction of the magnetic field and in a direction opposite to the diagonally opposed TMR sensor elements of the second half-bridge,
wherein a non-null differential voltage output between the TMR sensor elements of the first half-bridge the TMR sensor elements of the second half-bridge is measurable when the field current is passed in the field line,
wherein the differential voltage output is insensitive to the presence of an external uniform magnetic field, and
wherein the pinning direction in each of the TMR sensor elements is oriented at about 45° relative to a tangent line of the field line.
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