MULTIPHASE VOLTAGE REGULATOR HAVING COUPLED INDUCTORS WITH REDUCED WINDING RESISTANCE

Abstract

A multiple phase buck converter or boost converter, or buck-boost converter has an inductor in each phase. The inductors are inversely coupled. In a first embodiment, the converter includes a toroidal magnetic core with inductors extending under and over opposite sides of the toroidal magnetic core. The coupled inductors are thereby inversely coupled and have a relatively low ohmic resistance. In a second embodiment, the converter comprises a ladder-shaped magnetic core (i.e. having parallel sides, and connecting rungs). In this case, the inductors extend under the sides, and over the rungs. Each inductor is disposed over a separate rung. The ladder-shaped magnetic core is preferably disposed flat on a circuit board. Inverse coupling and low ohmic resistance are also provided in the second embodiment having the ladder structure.

Description

DESCRIPTION OF FIGURES

FIG. 1 (Prior Art) shows a circuit schematic of a 2-phase buck converter with coupled inductors.

FIG. 2 (Prior Art) shows a conventional implementation of coupled inductors. The conventional implementation requires inductors having loops.

FIG. 3 (Prior Art) shows a perspective view of the inductors of FIG. 2 without the magnetic core.

FIG. 4 shows a coupled inductor with a toroidal magnetic core according to the present invention.

FIG. 5 shows the inductors of the device of FIG. 4 in isolation (i.e. without the toroidal magnetic core).

FIG. 6 shows a cross sectional side view of the device of FIG. 4 disposed flat on a circuit board.

FIG. 7 shows an alternative embodiment having a ladder structure magnetic core disposed on the circuit board 42.

FIG. 8 shows a ladder structure magnetic core in isolation.

FIG. 9 shows the inductors of the device of FIG. 7 in isolation.

FIG. 10 shows a top view of a ladder structure magnetic core with 4 coupled inductors. The device of FIG. 10 can be used with 4-phase voltage converters.

FIG. 11 shows a top view of an embodiment in which the inductors are straight as viewed from above. In this embodiment, the inductors have a minimal length.

FIG. 12 shows a circuit diagram of a boost converter which can employ the coupled inductors of the present invention.

FIG. 13 shows a circuit diagram of a buck-boost converter which can employ the coupled inductors of the present invention.

Claims

1-19. (canceled)

20. A multiphase coupled inductor for a multiphase voltage converter, comprising: a magnetic core having a ladder structure comprising a first rail extending in a rail direction, a second rail extending approximately parallel to the first rail, a first connecting rung connecting said first rail to said second rail, and a second connecting rung connecting said first rail to said second rail;a first inductor extending under the first rail, over the first connecting rung, and under the second rail; anda second inductor extending under the first rail, over the second connecting rung, and under the second rail,wherein the first connecting rung extends from the first rail to the second rail in a direction substantially nonperpendicular to said rail direction, andwherein the second connecting rung extends from the first rail to the second rail in a linear direction substantially nonperpendicular to said rail direction.

21. The multiphase coupled inductor of claim 20, wherein the first connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 20-70 degrees, andwherein the second connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 20-70 degrees.

22. The multiphase coupled inductor of claim 20, wherein the first connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 30-60 degrees, andwherein the first connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 30-60 degrees.

23. The multiphase coupled inductor of claim 20, wherein the first inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the first connecting rung and the second rail, andwherein the second inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the second connecting rung and the second rail.

24. The multiphase coupled inductor of claim 21, wherein the first inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the first connecting rung and the second rail, andwherein the second inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the second connecting rung and the second rail.

25. The multiphase coupled inductor of claim 22, wherein the first inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the first connecting rung and the second rail, andwherein the second inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the second connecting rung and the second rail.

26. The multiphase coupled inductor of claim 20, wherein the first connecting rung extends substantially parallel to the second connecting rung.

27. The multiphase coupled inductor of claim 21, wherein the first connecting rung extends substantially parallel to the second connecting rung.

28. The multiphase coupled inductor of claim 22, wherein the first connecting rung extends substantially parallel to the second connecting rung.

29. The multiphase coupled inductor of claim 23, wherein the first connecting rung extends substantially parallel to the second connecting rung.

30. The multiphase coupled inductor of claim 24, wherein the first connecting rung extends substantially parallel to the second connecting rung.

31. The multiphase coupled inductor of claim 25, wherein the first connecting rung extends substantially parallel to the second connecting rung.

32. The multiphase coupled inductor of claim 20, further comprising: a third connecting rung connecting said first rail to said second rail;a fourth connecting rung connecting said first rail to said second rail;a third inductor extending under the first rail, over the third connecting rung; anda fourth inductor extending under the first rail, over the fourth connecting rung,wherein the third connecting rung extends from the first rail to the second rail in a direction substantially nonperpendicular to said rail direction, andwherein the fourth connecting rung extends from the first rail to the second rail in a direction substantially nonperpendicular to said rail direction.

33. The multiphase coupled inductor of claim 32, wherein the first connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 20-70 degrees,wherein the second connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 20-70 degrees,wherein the third connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 20-70 degrees, andwherein the fourth connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 20-70 degrees.

34. The multiphase coupled inductor of claim 32, wherein the first connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 30-60 degrees,wherein the second connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 30-60 degrees,wherein the third connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 30-60 degrees, andwherein the fourth connecting rung extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 30-60 degrees.

35. The multiphase coupled inductor of claim 32, wherein the first inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the first connecting rung and the second rail,wherein the second inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the second connecting rung and the second rail,wherein the third inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the third connecting rung and the second rail, andwherein the third inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the third connecting rung and the second rail.

36. The multiphase coupled inductor of claim 33, wherein the first inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the first connecting rung and the second rail,wherein the second inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the second connecting rung and the second rail, andwherein the third inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the third connecting rung and the second rail.

37. The multiphase coupled inductor of claim 34, wherein the first inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the first connecting rung and the second rail,wherein the second inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the second connecting rung and the second rail, andwherein the third inductor, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, the third connecting rung and the second rail.

38. The multiphase coupled inductor of claim 32, wherein the first connecting rung, the second connecting rung and the third connecting rung extend substantially parallel to one another.

39. The multiphase coupled inductor of claim 33, wherein the first connecting rung, the second connecting rung and the third connecting rung extend substantially parallel to one another.

40. The multiphase coupled inductor of claim 34, wherein the first connecting rung, the second connecting rung and the third connecting rung extend substantially parallel to one another.

41. The multiphase coupled inductor of claim 35, wherein the first connecting rung, the second connecting rung and the third connecting rung extend substantially parallel to one another.

42. The multiphase coupled inductor of claim 36, wherein the first connecting rung, the second connecting rung and the third connecting rung extend substantially parallel to one another.

43. The multiphase coupled inductor of claim 37, wherein the first connecting rung, the second connecting rung and the third connecting rung extend substantially parallel to one another.

44. A multiphase coupled inductor for a multiphase voltage converter, comprising: a magnetic core having a ladder structure comprising a first rail extending in a rail direction, a second rail extending approximately parallel to the first rail, and a plurality of connecting rungs connecting said first rail to said second rail; anda plurality of inductors, each of said inductors extending under the first rail, over a corresponding one of said connecting rungs, and under the second rail,wherein each of said connecting rungs extends from the first rail to the second rail in a direction substantially nonperpendicular to said rail direction.

45. The multiphase coupled inductor of claim 44, wherein at least one of said connecting rungs extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 20-70 degrees.

46. The multiphase coupled inductor of claim 44, wherein at least one of said connecting rungs extends from the first rail to the second rail in a direction forming an included angle with the rail direction, said included angle being in the range of 30-60 degrees.

47. The multiphase coupled inductor of claim 44, wherein at least one of said inductors, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, not more than one of said connecting rungs, and the second rail.

48. The multiphase coupled inductor of claim 45, wherein at least one of said inductors, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, not more than one of said connecting rungs, and the second rail.

49. The multiphase coupled inductor of claim 46, wherein at least one of said inductors, projected onto a reference plane having the first rail and the second rail, forms a straight line crossing the first rail, not more than one of said connecting rungs, and the second rail.

50. The multiphase coupled inductor of claim 20, wherein said first connecting rung and said second connecting rung extend substantially on a mutually common plane.

51. The multiphase coupled inductor of claim 50, wherein said first rail and said second rail extend substantially coplanar with said common plane.

52. The multiphase coupled inductor of claim 32, wherein said first connecting rung, said second connecting rung, said third connecting rung and said fourth connecting rung extend substantially coplanar with a mutually common plane.

53. The multiphase coupled inductor of claim 52, wherein said first rail and said second rail extend substantially coplanar with said common plane.

54. The multiphase coupled inductor of claim 44, wherein all of said plurality of connecting rungs extend substantially coplanar with a common plane.

55. The multiphase coupled inductor of claim 54, wherein said first rail and said second rail extend substantially coplanar with said common plane.