Active shielding for a circuit comprising magnetically sensitive materials
View Patent ↗The present invention provides a method for providing magnetic shielding for a circuit comprising magnetically sensitive materials, comprising actively shielding the circuit from a disturbing magnetic field. A corresponding semiconductor device is also provided. The method and device allows shielding for strong disturbing magnetic fields.
1. A method for providing magnetic shielding for an integrated circuit die having magnetically sensitive materials that use a magneto-resistive effect to store data, the magneto-resistive effect controlled using a local magnetic field, the method comprising:
sensing a disturbing magnetic field near the magnetically sensitive material; and
responsive to the sensing, actively shielding the magnetically sensitive materials from the disturbing magnetic field by generating a compensating magnetic field.
2. The method according to claim 1 , wherein
measuring a disturbing magnetic field includes determining a direction of the disturbing magnetic field, and
the compensating magnetic field is in a primarily opposite direction from the disturbing magnetic field.
3. The method according to claim 2 , wherein compensating for the measured disturbing magnetic field includes generating a magnetic compensation field.
4. The method according to claim 2 , further including determining whether compensating for the measured disturbing magnetic field is necessary.
5. The method according to claim 4 , wherein determining whether compensating is necessary includes comparing a measured disturbing magnetic field value with a pre-set threshold value.
6. The method according to claim 1 , further including passively shielding the circuit from the disturbing magnetic field.
7. A semiconductor device comprising:
a storage circuit comprising magnetically sensitive materials that use a magneto-resistive effect to store data, the magneto-resistive effect controlled using a local magnetic field;
a sensor for measuring the disturbing magnetic field; and
a protective layer for actively shielding the magnetically sensitive materials from a disturbing magnetic field in response to measuring the disturbing magnetic field.
8. The device of claim 7 , wherein the protective layer for actively shielding the circuit includes:
a compensation generator for generating a magnetic field in the protective layer for compensating for the disturbing magnetic field.
9. The device of claim 8 , wherein the sensor is integrated in the storage circuit.
10. The device of claim 8 , wherein the sensor is a Hall sensor.
11. The device of claim 7 , wherein the sensor is part of a circuit arrangement generating a spin polarized current through the circuit for disturbance compensation.
12. A device, comprising:
an integrated circuit die having magnetically sensitive materials that use a magneto-resistive effect to store data, the magneto-resistive effect controlled using a local magnetic field;
means for sensing a disturbing magnetic field near the magnetically sensitive material; and
means, responsive to the sensing means, for actively shielding the magnetically sensitive materials from the disturbing magnetic field by generating a compensating magnetic field.
13. The device of claim 12 , further including determining a direction of the disturbing magnetic field, and wherein the compensating magnetic field is in a primarily opposite direction from the disturbing magnetic field.
14. The device of claim 13 , further including means for generating a spin polarized current through the circuit.