Integrated circuit including a magnetic field sensitive element and a coil
An integrated circuit includes a die and a first magnetic field sensitive element formed on the die. The integrated circuit includes a first coil formed on the die and around the first magnetic field sensitive element.
1. An integrated circuit comprising:
a die;
a first magnetic field sensitive element formed on the die;
a first coil formed on the die and surrounding the first magnetic field sensitive element;
a first amplifier configured to amplify a first signal from the first magnetic field sensitive element;
a second amplifier configured to amplify a second signal from the first coil;
a first low pass filter configured to filter the amplified first signal to provide a first amplified and filtered first signal; and
a second low pass filter configured to filter the amplified second signal to provide a second amplified and filtered second signal.
2. The integrated circuit of claim 1 , wherein the first magnetic field sensitive element comprises a spinning current Hall probe.
3. The integrated circuit of claim 1 , wherein the first magnetic field sensitive element consists of one of a magneto-resistive sensor element, a magneto-diode, and a magneto-transistor.
4. The integrated circuit of claim 1 , wherein the first coil is formed in at least two interconnect layers of the die and includes at least two turns within a single interconnect layer of the die.
5. The integrated circuit of claim 1 , further comprising:
a summing block configured to add the first amplified and filtered first signal to the second amplified and filtered second signal to provide a signal indicating a magnetic field acting on the first magnetic field sensitive element and the first coil.
6. The integrated circuit of claim 5 , wherein the integrated circuit is configured to sense a magnetic field having a frequency within a range from 0 Hz to 100 kHz.
7. An integrated circuit comprising:
a die;
a first magnetic field sensitive element formed on the die;
a first coil formed on the die and surrounding the first magnetic field sensitive element;
a second magnetic field sensitive element formed on the die; and
a second coil formed on the die and around the second magnetic field sensitive element;
a first amplifier configured to amplify a first signal indicating a difference between a signal from the first magnetic field sensitive element and a signal from the second magnetic field sensitive element; and
a second amplifier configured to amplify a second signal indicating a difference between a signal from the first coil and a signal from the second coil.
8. The integrated circuit of claim 7 , further comprising:
a first low pass filter configured to filter the amplified first signal to provide a first amplified and filtered first signal; and
a second low pass filter configured to filter the amplified second signal to provide a second amplified and filtered second signal.
9. The integrated circuit of claim 8 , further comprising:
a summing block configured to add the first amplified and filtered first signal to the second amplified and filtered second signal to provide a signal indicating a magnetic field acting on the first magnetic field sensitive element, the second magnetic field sensitive element, the first coil, and the second coil.
10. A system comprising:
a controller; and
a magnetic field sensor communicatively coupled to the controller, the magnetic field sensor comprising:
a die;
a first magnetic field sensitive element formed on the die;
a first coil formed on the die and surrounding the first magnetic field sensitive element;
a first amplifier configured to amplify a first signal from the first magnetic field sensitive element;
a second amplifier configured to amplify a second signal from the first coil;
a first low pass filter configured to filter the amplified first signal to provide a first amplified and filtered first signal; and
a second low pass filter configured to filter the amplified second signal to provide a second amplified and filtered second signal.
11. The system of claim 10 , wherein the first magnetic field sensitive element comprises a spinning current Hall probe.
12. The system of claim 10 , wherein the first magnetic field sensitive element consists of one of a magneto-resistive sensor element, a magneto-diode, and a magneto-transistor.
13. The system of claim 10 , wherein the magnetic field sensor further comprises:
a second magnetic field sensitive element formed on the die; and
a second coil formed on the die and around the second magnetic field sensitive element, the second coil adjacent to the first coil.
14. The system of claim 13 , wherein the first coil is electrically coupled to the second coil.
15. The system of claim 10 , wherein the magnetic field sensor is configured to sense a magnetic field having a frequency within a range from 0 Hz to 100 kHz.
16. A method for sensing a magnetic field, the method comprising:
providing a first magnetic field sensitive element and a first coil surrounding the first magnetic field sensitive element on a die;
amplifying a first signal from the first magnetic field sensitive element;
amplifying a second signal from the first coil;
low pass filtering the amplified first signal;
low pass filtering the amplified second signal; and
outputting a sum of the filtered first signal and the filtered second signal indicating a magnetic field acting on the first magnetic field sensitive element and the first coil.
17. The method of claim 16 , wherein providing the magnetic field sensitive element comprises providing a spinning current Hall probe.
18. The method of claim 16 , wherein providing the magnetic field sensitive element consists of one of a magneto-resistive sensor element, a magneto-diode, and a magneto-transistor.
19. The method of claim 16 , wherein outputting the sum comprises outputting a signal indicating a magnetic field having a frequency within a range of 0 Hz to 100 kHz.
20. A method for sensing a magnetic field, the method comprising:
providing a first magnetic field sensitive element and a first coil surrounding the first magnetic field sensitive element on a die;
outputting a signal indicating a magnetic field acting on the first magnetic field sensitive element and the first coil;
providing a second magnetic field sensitive element and a second coil around the second magnetic field sensitive element on the die; and
outputting a signal indicating a difference between a magnetic field acting on the first magnetic field sensitive element and the first coil and the magnetic field acting on the second magnetic field sensitive element and the second coil.