Mutual Inductance Circuits

• US 20130082793A1
• Filed: 09/30/2011
• Published: 04/04/2013
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Eldredge, Adam B., Hara, Susumu
• Granted Patent: US 8,648,664 B2
• Time in Patent Office: Days
• US Class Current: 331/167
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H03B 5/08 with frequency-determining element comprising lumped inductance and capacitance

Abstract

An apparatus includes a first conductive loop coupled to conduct a first current and a second conductive loop coupled in parallel with the first conductive loop and further coupled to conduct a second current. A first conductive portion forms a part of the first conductive loop and the second conductive loop. The first conductive portion is coupled to conduct the first current and the second current. In at least one embodiment of the apparatus, the first conductive loop and the second conductive loop are planar inductors formed in a conductive layer on a substrate of an integrated circuit.

Claims

1. An apparatus comprising:

a first conductive loop coupled to conduct a first current; and

a second conductive loop coupled in parallel with the first conductive loop and further coupled to conduct a second current,

wherein a first conductive portion forms a part of the first conductive loop and the second conductive loop, the first conductive portion coupled to conduct the first current and the second current.

2. The apparatus as recited in claim 1,

wherein the first current rotates in a first direction and the second current rotates in a second direction opposite to the first direction.

3. The apparatus as recited in claim 1,

wherein the first conductive loop and the second conductive loop are planar inductors formed in a conductive layer on a substrate of an integrated circuit.

4. The apparatus as recited in claim 1 further comprising:

a third conductive loop; and

a fourth conductive loop coupled in parallel with the first, second, and third conductive loops.

5. The apparatus as recited in claim 4,

wherein a second conductive portion forms a part of the first conductive loop and the third conductive loop, and

wherein a third conductive portion forms a part of the second conductive loop and the fourth conductive loop.

6. The apparatus as recited in claim 5,

wherein a fourth conductive portion forms a part of the third conductive loop and the fourth conductive loop.

7. The apparatus as recited in claim 6 further comprising:

an additional conductive portion coupling the first conductive portion to the fourth conductive portion.

8. The apparatus as recited in claim 6 further comprising:

a fifth conductive portion that forms a portion of the first, second, third, and fourth conductive loops.

9. The apparatus as recited in claim 4,

wherein all sides of each of the first, second, third, and fourth conductive loops are shared with adjacent conductive loops.

10. The apparatus as recited in claim 1, wherein every side of the first conductive loop includes a portion of a corresponding adjacent conductive loop, the corresponding adjacent conductive loops conducting respective currents that rotate in a direction opposite to the direction of rotation of the first current.

11. The apparatus as recited in claim 1 further comprising:

an oscillator circuit including the first conductive loop, the second conductive loop, and a capacitor coupled in parallel with the first conductive loop and the second conductive loop.

12. The apparatus as recited in claim 1,

wherein the first conductive loop and the second conductive loop further share a second conductive portion, the first conductive portion and the second conductive portion being separated by a gap, the first conductive portion including a first terminal and the second conductive portion including a second terminal, the first and second terminals being configured to couple the first conductive loop in parallel with the second conductive loop.

13. The apparatus as recited in claim 1,

wherein the first conductive loop and the second conductive loop are inductors that are substantially single-turn.

14. A method comprising:

generating a magnetic field determined by first and second currents through a conductive portion shared by respective first and second conductive loops coupled in parallel.

15. The method as recited in claim 14, wherein generating the magnetic field comprises combining the first and second currents at the conductive portion.

16. The method as recited in claim 14, wherein generating the magnetic field comprises separating a current flowing in the conductive portion into the first and second currents.

17. The method as recited in claim 14, wherein generating the magnetic field comprises distributing a portion of the first current in a peripheral direction.

18. The method as recited in claim 14,

wherein the first and second currents rotate in respective first and second directions, the first direction substantially opposite to the second direction.

19. The method as recited in claim 14,

wherein the magnetic field is based on a mutual inductance between the first and second conductive loops, the mutual inductance determined by the conductive portion.

20. An apparatus comprising:

means for conducting a first loop current; and

means for conducting a second loop current,

wherein the means for conducting the first loop current and the means for conducting the second loop current include means for combining the first loop current and the second loop current.

21. The apparatus as recited in claim 20,

wherein the means for conducting the first loop current includes means for distributing a portion of the first current in a peripheral direction.