MAGNETIC FIELD SENSOR DEVICE

• US 20150309128A1
• Filed: 04/28/2014
• Published: 10/29/2015
• Est. Priority Date: 04/28/2014
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Raberg, Wolfgang
• Granted Patent: US 10,649,043 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 33/0041 using feed-back or modulation techniques
• CPC Class Codes: G01R 33/09 Magnetoresistive devices
• CPC Class Codes: G01R 33/098 comprising tunnel junctions, e.g. tunnel magnetoresistance sensors

Abstract

Magnetic field sensor devices and associated methods are disclosed. In some implementations, a second magnetic field sensor is provided, for example between bridge parts of a first magnetic field sensor.

Claims

1. A magnetic field sensor device, comprising:

a first magnetic field sensor, the first magnetic field sensor comprising a bridge circuit, a first bridge part of the bridge circuit being spatially separate from a second bridge part of the bridge circuit, and

a second magnetic field sensor.

2. The device of claim 1, wherein the bridge circuit comprises resistors exhibiting at least one of a giant magnetoresistance and a tunnel magnetoresistance.

3. The magnetic field sensor device of claim 1, wherein the second magnetic field sensor is arranged spatially between the first bridge part and the second bridge part.

4. The device of claim 1, wherein the second magnetic field sensor comprises a further bridge circuit.

5. The device of claim 4, wherein the further bridge circuit comprises resistors exhibiting at least one of a giant magnetoresistance and a tunnel magnetoresistance.

6. The device of claim 4, wherein the further bridge circuit comprises at least one resistor comprising elliptical elements coupled in series.

7. The device of claim 4, wherein the further bridge circuit comprises a first resistor of a first type coupled in series with a second resistor of a second, different type, and a third resistor of the second type coupled in series with a fourth resistor of the first type, the series connection of the first and second resistors being coupled in parallel to the series connection of the third and fourth resistors.

8. The device of claim 7, wherein the first type has a sensitivity different from a sensitivity of the second type.

9. The magnetic field sensor device of claim 1, further comprising a control circuit to derive a speed from a measurement of the first magnetic field sensor and to derive a proximity of a magnet from a measurement of the second magnetic field sensor.

10. The device of claim 1, wherein the second magnetic field sensor comprises a further bridge circuit, and

wherein the second magnetic field sensor is spatially arranged between the first bridge part and the second bridge part.

11. The device of claim 1, wherein the bridge circuit comprises a differential bridge circuit.

12. A method, comprising:

measuring a modulation of a magnetic field using a bridge circuit with spatially separated bridge branches, and

measuring a strength of the magnetic field using a magnetic field sensor located between the spatially separated bridge branches.

13. The method of claim 12, further comprising deriving a speed from the measured modulation.

14. The method of claim 12, further comprising deriving a proximity of a magnet from the measured strength.

15. The method of claim 12, further comprising detecting a fault of at least one of the bridge circuit and the magnetic field sensor based on at least one of measuring the modulation and measuring the strength.

16. The method of claim 12, wherein measuring the modulation and measuring the strength comprises at least one of detecting a giant magnetoresistance change or a tunnel magnetoresistance change.

17. A method, comprising:

providing a first magnetic field sensor with spatially separate bridge parts, and

providing a second magnetic field sensor between the spatially separate bridge parts.

18. The method of claim 17, wherein providing the second magnetic field sensor comprises providing the second magnetic field sensor as a bridge circuit.

19. The method of claim 17, wherein providing the first magnetic field sensor comprises providing the spatially separate bridge parts with magnetoresistive resistors.

20. The method of claim 17, wherein providing the second magnetic field sensor comprises providing magnetoresistive resistors, at least two of the magnetoresistive resistors having different dimensions.

21. The method of claim 17, wherein providing the first magnetic field sensor and providing the second magnetic field sensor comprises at least one common processing phase for forming the first and second magnetic field sensor.

22. The method of claim 21, wherein the at least one common processing phase comprises a material deposition phase depositing material to form the first and second magnetic field sensors.

23. The method of claim 22, wherein the material comprises a magnetically active material.