Integrated current sensor

• US 6,781,359 B2
• Filed: 09/20/2002
• Issued: 08/24/2004
• Est. Priority Date: 09/20/2002
• Status: Expired due to Term

• Current Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Original Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Inventors: Dickinson, Richard, Sauber, John, Stauth, Jason, Pinelle, Sandra, Engel, Ray
• Primary Examiner(s): KARLSEN, ERNEST F
• Application Number:
  US10/251,007
• Publication Number:
  US 20040056647A1
• Time in Patent Office: 704 Days
• Field of Search: 324/117.H, 324/117.R, 324/126, 324/127, 324/251, 324/252, 338/32.R, 338/32.H, 338/49
• US Class Current: 324/117.00H
• CPC Class Codes: G01R 15/202 using Hall-effect devices Hall elements in arrangements for measuring electrical power G01R21/08

Abstract

An integrated current sensor includes a magnetic field transducer such as a Hall effect sensor, a magnetic core, and an electrical conductor. The conductor includes features for receiving portions of the Hall effect sensor and the core and the elements are dimensioned such that little or no relative movement among the elements is possible.

Claims

1. A current sensor comprising:

a conductor having a first notch and a second notch substantially aligned with the first notch;

a magnetic field transducer having at least a portion disposed in the first notch; and

a magnetic core having a central region and a pair of substantially parallel legs extending from said central region, wherein at least a portion of said central region is disposed in the second notch and wherein at least a portion of each leg covers at least a portion of a respective surface of the magnetic field transducer.

2. The current sensor of claim 1, wherein said magnetic field transducer comprises a selected one of a Hall effect element and a magnetoresistance element.

3. The current sensor of claim 2, wherein said magnetic field transducer comprises a selected one of a giant magnetoresistance (GMR) element and an anisotropic magnetoresistance (AMR) element.

4. The current sensor of claim 1, wherein the width of said portion of said magnetic field transducer disposed in the first notch is substantially equal to the width of said first notch so that said magnetic field transducer is in a substantially fixed position with respect to said conductor.

5. The current sensor of claim 1, wherein the width of said central region of said magnetic core disposed in the second notch is substantially equal to the width of said second notch so that said magnetic core is in a substantially fixed position with respect to said conductor.

6. The current sensor of claim 1, wherein each of said legs of said magnetic core covers substantially an entire surface of the magnetic field transducer.

7. The current sensor of claim 1, wherein said first and second notches are located in a central region of said conductor and said conductor comprises a mounting mechanism at end regions thereof.

8. The current sensor of claim 7, wherein said mounting mechanism comprises a through-hole adapted to receive board-mounting hardware.

9. The current sensor of claim 7, wherein said mounting mechanism comprises a bent lead adapted to be inserted into a through-hole of a printed circuit board.

10. The current sensor of claim 7, wherein said mounting mechanism comprises a flat lead for soldering to a pad of a printed circuit board.

11. The current sensor of claim 7, wherein said mounting mechanism comprises a wire mounting mechanism.

12. The current sensor of claim 1, wherein the conductor is elongated along a first axis and wherein the magnetic field transducer has at least one electrical lead extending along a second axis substantially orthogonal to the first axis.

13. The current sensor of claim 1, wherein the magnetic field transducer further comprises at least one amplifier.

14. The current sensor of claim 13, wherein said at least one amplifier has a gain adapted to be trimmed.

15. The current sensor of claim 1, wherein the magnetic core is comprised of a material selected from the group consisting of ferrite, steel, iron compound, and permalloy.

16. The current sensor of claim 1, further comprising a molded body encapsulating at least a portion of said magnetic field transducer, said conductor and said magnetic core.

17. The current sensor of claim 1, wherein the pair of substantially parallel legs are spaced by a distance substantially equal to a thickness of said magnetic field transducer.

18. The current sensor of claim 1, wherein the pair of substantially parallel legs are spaced by a distance greater than a thickness of said magnetic field transducer.