Current sensor

• US 9,103,853 B2
• Filed: 10/07/2014
• Issued: 08/11/2015
• Est. Priority Date: 11/18/2010
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Ausserlechner, Udo, Scherr, Wolfgang
• Primary Examiner(s): Koval, Melissa
• Assistant Examiner(s): NGUYEN, TRUNG Q
• Application Number:
  US14/508,670
• Publication Number:
  US 20150061662A1
• Time in Patent Office: 308 Days
• Field of Search: 324/163, 324/173, 324/174, 32420711-20715, 702/138, 702/145, 702/130, 73766-767, 737/74, 737/77, 737/79
• US Class Current: 1/1
• CPC Class Codes: G01R 15/207 Constructional details independent of the type of device used
• CPC Class Codes: G01R 19/0092 measuring current only all subgroups of G01R19/00 take precedence
• CPC Class Codes: G01R 33/07 Hall effect devices
• CPC Class Codes: G01R 33/091 Constructional adaptation of the sensor to specific applications
• CPC Class Codes: G01R 33/18 Measuring magnetostrictive properties
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details

Abstract

Embodiments of the disclosure provide a current sensor including a conductive element and at least two magnetic field sensors. The conductive element includes at least three separate terminal areas, a common conductive area and at least three separate intermediate areas connecting the respective separate terminal areas to the common conductive area. Each of the terminal areas is connected separately via a respective separate intermediate area of the at least three separate intermediate areas to the common conductive area to guide a current applied to the respective terminal area into the common conductive area. The at least two magnetic field sensors are arranged at different geometric positions adjacent to the at least three separate intermediate areas, wherein each of the magnetic field sensors is configured to sense a magnetic field component of each current flowing into the common conductive area to provide a sensor signal based thereon.

Claims

1. A current sensor, comprising:

a conductive element with at least three separate terminal areas, a common conductive area and at least three separate intermediate areas connecting the at least three separate terminal areas to the common conductive area, wherein each of the at least three separate terminal areas is connected separately via a respective separate intermediate area of the at least three separate intermediate areas to the common conductive area to guide separately a current applied to the respective terminal area into the common conductive area; and

at least two magnetic field sensors arranged at different geometric positions adjacent to the at least three separate intermediate areas, wherein each of the at least two magnetic field sensors is configured to sense a magnetic field component of the current flowing into the common conductive area to provide a sensor signal based on the sensed magnetic field component;

wherein the at least two magnetic field sensors are arranged adjacent to the at least three separate intermediate areas such that the current sensor can measure separately the currents guided by the at least three separate terminal areas via the at least three separate intermediate areas into the common conductive area; and

wherein a geometric area surrounding and abutting the common conductive area is divided into two geometric sectors, each of the two geometric sectors abutting the common conductive area, wherein the at least three terminal areas are arranged in a first geometric sector of the two geometric sectors, and wherein signal and supply terminals of the at least two magnetic field sensors are arranged in a second geometric sector of the two geometric sectors.

2. The current sensor according to claim 1, wherein the geometric area completely surrounds the common conductive area.

3. The current sensor according to claim 1, wherein the geometric area is divided into exactly two geometric sectors.

4. The current sensor according to claim 1, wherein the two geometric sectors are two circular sectors, wherein a sum of central angles of the two circular sectors is equal to 360°

.

5. The current sensor according to claim 1, wherein a central angle of the first circular sector is equal to or greater than 300°

.

6. The current sensor according to claim 1, wherein a first separate terminal area of the at least three separate terminal areas is connected via a first separate intermediate area of the at least three separate intermediate areas to the common conductive area;

wherein a second separate terminal area of the at least three separate terminal areas is connected via a second separate intermediate area of the at least three separate intermediate areas to the common conductive area; and

wherein a third separate terminal area of the at least three separate terminal areas is connected via a third separate intermediate area of the at least three separate intermediate areas to the common conductive area.

7. The current sensor according to claim 1, further comprising an evaluator configured to determine a value of each current flowing into the common conductive area based on the sensor signals of the at least two magnetic field sensors.

8. The current sensor according to claim 7, wherein the evaluator is configured to derive a value of a background magnetic field based on the sensor signals of the at least two magnetic field sensors, and to determine evaluate the value of each current flowing into the common conductive area further based on the value of the background magnetic field.

9. The current sensor according to claim 7, wherein the evaluator comprises an output for outputting the value of each current flowing into the common conductive area.

10. The current sensor according to claim 1, wherein each current flowing into the common conductive area generates a magnetic field through each of the at least two magnetic field sensors.

11. The current sensor according to claim 1, wherein the at least two magnetic field sensors are arranged on different positions corresponding to a geometric line.

12. The current sensor according to claim 1, wherein the at least two magnetic field sensors are arranged symmetrically on different positions corresponding to a geometric line.

13. The current sensor according to claim 1, wherein each of the at least two magnetic field sensors is arranged between two adjacent separate intermediate areas.

14. The current sensor according to claim 1, wherein each of the at least two magnetic field sensors is arranged between two adjacent separate intermediate areas immediately adjacent to the common conductive area.

15. The current sensor according to claim 1, wherein each of the at least three separate intermediate areas is arranged to define a center line associated therewith such that the center lines extend from the at least three separate terminal areas to the common conductive area, and wherein each of the at least two magnetic field sensors is arranged on the center line of the respective separate intermediate area.

16. The current sensor according to claim 15, wherein each of the at least two magnetic field sensors is arranged at an equal distance from the common conductive area on the center line of the respective separate intermediate area.

17. The current sensor according to claim 1, wherein the at least two magnetic field sensors are discrete sensors.

18. The current sensor according to claim 1, wherein the at least two magnetic field sensors are part of an integrated circuit.

19. The current sensor according to claim 1, wherein each current flowing into the common conductive area provides a mean temperature increase to each of the at least two magnetic field sensors, wherein a maximum tolerance in increase of temperature between two magnetic field sensors amounts to 10% of the mean temperature increase.

20. The current sensor according to claim 1, wherein the at least three separate terminal areas and the at least three separate intermediate areas are in an area outside of the common conductive area isolated from each other by an isolating material.

21. The current sensor according to claim 1, wherein in a plan view the common conductive area is surrounded by the at least two magnetic field sensors.

22. The current sensor according to claim 1, wherein the conductive element comprises a homogenous electric conducting material with an electrical conductivity of at least 3*10^7 S/m.

23. A current sensor, comprising:

a conductive element with n separate terminal areas and n separate intermediate areas, wherein n is at least three, and a common conductive area, wherein each of the n separate terminal areas is connected separately via a respective separate intermediate area of the n separate intermediate areas to the common conductive area and configured to guide separately a current applied to the respective terminal area into the common conductive area; and

m magnetic field sensors, wherein m is at least two, arranged at different geometric positions adjacent to the separate intermediate areas, wherein each of the m magnetic field sensors is configured to sense a magnetic field component of the current flowing into the common conductive area to provide a sensor signal based on the sensed magnetic field component, wherein the m magnetic field sensors are arranged at different geometric positions adjacent to the separate intermediate areas such that the current sensor can measure separately the currents guided by the n separate terminal areas via the n separate intermediate areas into the common conductive area;

wherein a geometric area surrounding and abutting the common conductive area is divided into two geometric sectors, each of the two geometric sectors abutting the common conductive area, wherein the n separate terminal areas are arranged in a first geometric sector of the two geometric sectors, and wherein signal and supply terminals of the at least two magnetic field sensors are arranged in a second geometric sector of the two geometric sectors.

24. The current sensor according to claim 23, wherein m=n.

25. The current sensor according to claim 23, wherein m=n−

1.

26. The current sensor according to claim 23, wherein m=n+1.

27. A method for measuring at least three separate currents in a measuring node, wherein the measuring node comprises at least two magnetic field sensors and a conductive element with at least three separate terminal areas, a common conductive area and at least three separate intermediate areas connecting the at least three separate terminal areas to the common conductive area, wherein each of the at least three separate terminal areas is connected separately via a respective separate intermediate area of the at least three separate intermediate areas to the common conductive area to guide separately one of the at least three currents applied to the respective terminal area into the common conductive area, wherein the at least two magnetic field sensors are arranged adjacent to the at least three separate intermediate areas such that values of the at least three currents separately guided by the at least three separate terminal areas via the at least three separate intermediate areas into the common conductive area are separately evaluated, wherein a geometric area surrounding and abutting the common conductive area is divided into two geometric sectors, each of the two geometric sectors abutting the common conductive area, wherein the at least three terminal areas are arranged in a first geometric sector of the two geometric sectors, and wherein signal and supply terminals of the at least two magnetic field sensors are arranged in a second geometric sector of the two geometric sectors, the method comprising:

sensing separately magnetic field components of the at least three separate currents flowing into the measuring node with the at least two magnetic field sensors; and

evaluating separately the values of the at least three separate currents flowing into the measuring node based on the separately sensed magnetic field components.

28. The method for measuring at least three currents in a measuring node according to claim 27, further with the following steps:

evaluating a value of a background magnetic field based on the sensed magnetic field component; and

evaluating the value of each current flowing into the measuring node further based on the value of the background magnetic field.

29. A computer readable non-transitory digital storage medium having stored thereon a computer program having a program code for performing, when running on a computer, a method for measuring at least three currents in a measuring node, wherein the measuring node comprises at least three magnetic field sensors and a conductive element, wherein the conductive element comprises at least three separate terminal areas, a common conductive area and at least three separate intermediate areas connecting the at least three separate terminal areas to the common conductive area, wherein each of the at least three separate terminal areas is separately connected via a respective separate intermediate area of the at least three separate intermediate areas to the common conductive area to separately guide one of the at least three currents applied to the respective terminal area into the common conductive area, wherein the at least two magnetic field sensors are arranged adjacent to the at least three separate intermediate areas such that values of the at least three currents separately guided by the at least three separate terminal areas via the at least three separate intermediate areas into the common conductive area are separately evaluated, wherein a geometric area surrounding and abutting the common conductive area is divided into two geometric sectors, each of the two geometric sectors abutting the common conductive area, wherein the at least three terminal areas are arranged in a first geometric sector of the two geometric sectors, and wherein signal and supply terminals of the at least two magnetic field sensors are arranged in a second geometric sector of the two geometric sectors, the method comprising:

sensing separately a magnetic field component of each current flowing into a measuring node with the at least two magnetic field sensors; and

evaluating separately the value of each current flowing into the measuring node based on the sensed magnetic field component.