Inductor Mountable on a Circuit Board
An inductor is disposed above and mounted on a printed wire board. The inductor includes a winding and a core. The winding includes first and second terminations that are electrically connected to the printed wire board at different locations. The core includes: a first section including magnetic material with a channel along an inner surface, to receive the winding, and ending at or above first and second bottom corners of the inner surface; a second section that is a mirror image of the first section including an inner surface that faces the inner surface of the first section; and a distributed gap that uniformly separates the first section from the second section except where the winding passes along the mirror-image channels. The winding lies along the distributed gap in the mirror-image channels, and the winding spatially divides the core into an upper and lower portions of equal volume.
1 . An inductor configured to be disposed above and mounted on a printed wire board, the inductor comprising:
a winding, comprising:
first and second terminations that are configured to be electrically connected to the printed wire board at different locations; and
a core, comprising:
a first section comprising magnetic material with a channel along an inner surface, configured to receive the winding, and ending at or above first and second bottom corners of the inner surface;
a second section that is a mirror image of the first section including an inner surface that faces the inner surface of the first section; and
a distributed gap that uniformly separates the first section from the second section except where the winding passes along the mirror-image channels,
wherein:
the winding lies along the distributed gap in the mirror-image channels of the first and second sections, and
the winding spatially divides the core into an upper portion and a lower portion that are equal in volume.
2 . The inductor of claim 1 , wherein the mirror-image channels that hold the winding end at the first and second bottom corners of the inner surfaces where the mirror-image channels bend by a first angle between 0 and 90 degrees and bend a second time by a second angle that is the complement of the first angle resulting in a horizontal portion of the mirror-image channels.
3 . The inductor of claim 2 , wherein the winding extends vertically downward from the first and second bottom corners.
4 . The inductor of claim 1 , wherein:
the first termination terminates in a slot in the printed wire board, and
the second termination terminates on a top surface of the printed wire board.
5 . The inductor of claim 4 , wherein the first and second terminations are coined.
6 . The inductor of claim 1 , wherein the inductor further comprises a wrap disposed around the core that fixes relative positions of the winding and the first and second sections of the core.
7 . The inductor of claim 1 , wherein the distributed gap is oriented perpendicularly to the printed wire board.
8 . The inductor of claim 1 , wherein the core further comprises at least one region of a nonmagnetic spacer.
9 . The inductor of claim 8 , wherein the nonmagnetic spacer comprises aromatic polyamide polymer.
10 . The inductor of claim 9 , wherein the nonmagnetic spacer comprises poly (m-phenylenediamine isophthalamide) paper.
11 . A system comprising:
a printed wire board; and
an inductor disposed above and mounted on the printed wire board, the inductor comprising:
a winding, comprising:
first and second terminations that are configured to be electrically connected to the printed wire board at different locations; and
a core, comprising:
a first section comprising magnetic material with a channel along an inner surface, configured to receive the winding, and ending at or above first and second bottom corners of the inner surface;
a second section that is a mirror image of the first section including an inner surface that faces the inner surface of the first section; and
a distributed gap that uniformly separates the first section from the second section except where the winding passes through the mirror-image channels,
wherein:
the winding lies along the distributed gap in the mirror-image channels of the first and second sections, and
the winding spatially divides the core into an upper portion and a lower portion that are equal in volume.
12 . The system of claim 11 , wherein the mirror-image channels that hold the winding end at the first and second bottom corners of the inner surfaces where the mirror-image channels bend by a first angle between 0 and 90 degrees and bend a second time by a second angle that is the complement of the first angle resulting in a horizontal portion of the mirror-image channels.
13 . The system of claim 12 , wherein the winding extends vertically downward from the first and second bottom corners.
14 . The system of claim 11 , the system further comprising a converter that converts an input voltage to an output voltage that is different from the input voltage.
15 . The system of claim 14 , wherein the converter is a direct current to direct current converter that converts the input voltage to the output voltage that is less than the input voltage.
16 . The system of claim 15 , wherein:
the first and second terminations each comprise a pair of shoulders that extend outward from the winding in opposite directions,
the first termination terminates in a slot in the printed wire board, and
the second termination terminates on a top surface of the printed wire board.
17 . The system of claim 16 , wherein:
the first and second terminations are coined, and
the shoulders slope downward while extending outward.
18 . The system of claim 16 , wherein the second termination is disposed on a switch node side of the converter.
19 . The system of claim 13 , wherein both the first section and the second section of the core comprise a chamfered lower outward edge parallel to the horizontal portion of the mirror-image channels.
20 . The system of claim 11 , wherein the distributed gap is oriented perpendicularly to the printed wire board.
21 . The system of claim 11 , wherein the core further comprises at least one region of a nonmagnetic spacer.
22 . The system of claim 21 , wherein the nonmagnetic spacer comprises an aromatic polyamide polymer.
23 . The system of claim 22 wherein the nonmagnetic spacer comprises poly (m-phenylenediamine isophthalamide) paper.
24 . The system of claim 14 , wherein the converter comprises a non-isolated point-of-load DC-DC step-down converter with the input voltage greater than or equal to 7V and less than or equal to 14 V and the output voltage greater than or equal to 0.45 V and less than or equal to 2 V.
25 . The system of claim 24 , wherein the converter is configured to carry up to 40 amperes per phase.