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US7023313: Power inductor with reduced DC current saturation

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Filing Information

Inventor(s) Sehat Sutardja ·
Assignee(s) Marvell World Trade Ltd. ·
Primary Examiner Anh Mai ·
Application Number US10621128
Filing date 07/16/2003
Issue date 04/04/2006
Prior Publication Data
Predicted expiration date 12/20/2023
Patent term adjustment 157
U.S. Classifications 336/178  · 296/21  · 336/175  ·
International Classifications H01F1706  ·
Kind CodeB2
69 Claims, 7 Drawings


Abstract

A power inductor includes a magnetic core material having first and second ends. An inner cavity arranged in the magnetic core material extends from the first end to the second end. A conductor passes through the cavity. A slotted air gap arranged in the magnetic core material extends from the first end to the second end.

Independent Claims | See all claims (69)

  1. 1. A power inductor comprising: a magnetic core material having first and second ends; an inner cavity arranged in said magnetic core material that extends from said first end to said second end; a conductor that passes through said cavity; a slotted air gap arranged in said magnetic core material that extends from said first end to said second end; and an eddy current reducing material that is arranged adjacent to at least one of an inner opening of said slotted air gap in said cavity between said slotted air gap and said conductor and an outer opening of said slotted air gap, wherein said eddy current reducing material has a permeability that is lower than said magnetic core material.
  2. 14. A power inductor comprising: a magnetic core material having first and second ends; an inner cavity arranged in said magnetic core material that extends from said first end to said second end; a conductor that passes through said cavity; a slotted air gap arranged in said magnetic core material that extends from said first end to said second end, wherein said conductor passes through said cavity along a first side of said magnetic core material and said slotted air gap is arranged in a second side of said magnetic core material that is opposite said first side; a second conductor passes through said cavity along said first side; and a projection of said magnetic core material that extends outwardly from said first side between said conductor and said second conductor.
  3. 19. A power inductor comprising: a magnetic core material having first and second ends; an inner cavity arranged in said magnetic core material that extends from said first end to said second end; a conductor that passes through said cavity; a slotted air gap arranged in said magnetic core material that extends from said first end to said second end; a second cavity in said magnetic core material; a center “T”-shaped section arranged in said magnetic core material between said cavity and said second cavity; and a second conductor that passes through said second cavity adjacent to said first side, wherein said first conductor is arranged adjacent to said first side.
  4. 22. A method for reducing saturation in a power inductor, comprising: forming an inner cavity in a magnetic core material having first and second ends, wherein said inner cavity extends from said first end to said second end; passing a conductor through said cavity; providing a slotted air gap in said magnetic core material that extends from said first end to said second end; and locating an eddy current reducing material adjacent to at least one of an inner opening of said slotted air gap in said cavity between said slotted air gap and said conductor and an outer opening of said slotted air gap.
  5. 35. A method for reducing saturation in a power inductor, comprising: forming an inner cavity in a magnetic core material having first and second ends, wherein said inner cavity extends from said first end to said second end; passing a conductor through said cavity; providing a slotted air gap in said magnetic core material that extends from said first end to said second end; providing a second cavity in said magnetic core material; locating a center “T”-shaped section of said magnetic core material between said cavity and said second cavity; and passing a second conductor through said second cavity adjacent to said first side, wherein said first conductor is arranged adjacent to said first side.
  6. 38. A method for reducing saturation in a power inductor, comprising: forming an inner cavity in a magnetic core material having first and second ends, wherein said inner cavity extends from said first end to said second end; passing a conductor through said cavity; providing a slotted air gap in said magnetic core material that extends from said first end to said second end; passing said conductor through said cavity along a first side of said magnetic core material; arranging said slotted air gap along a second side of said magnetic core material that is opposite said first side; passing a second conductor through said cavity along said first side; and extending a projection of said magnetic core material outwardly from said first side between said conductor and said second conductor.
  7. 43. A power inductor comprising: magnetic core means for conducting a magnetic field and having first and second ends; cavity means arranged in said magnetic core means that extends from said first end to said second end for receiving conducting means for conducting current; slot means arranged in said magnetic core means that extends from said first end to said second end for reducing saturation of said magnetic core means, wherein said conducting means passes through said cavity means along a first side of said magnetic core means and said slot means is arranged in a second side of said magnetic core means that is opposite said first side; second conducting means that passes through said cavity means along said first side for conducting current; and projection means for extending outwardly from said first side between said conducting means and said second conducting means.
  8. 48. A power inductor comprising: magnetic core means for conducting a magnetic field and having first and second ends; cavity means arranged in said magnetic core means that extends from said first end to said second end for receiving conducting means for conducting current; slot means arranged in said magnetic core means that extends from said first end to said second end for reducing saturation of said magnetic core means; and second cavity means in said magnetic core means for receiving second conducting means for conducting current, wherein said magnetic core means includes a center “T”-shaped section located between said cavity means and said second cavity means; and wherein second conducting means is arranged adjacent to said first side, and wherein said first conducting means is arranged adjacent to said first side.
  9. 51. A power inductor comprising: magnetic core means for conducting a magnetic field and having first and second ends; cavity means arranged in said magnetic core means that extends from said first end to said second end for receiving conducting means for conducting current; slot means arranged in said magnetic core means that extends from said first end to said second end for reducing saturation of said magnetic core means; and eddy current reducing means, that is arranged at least one of adjacent to an inner opening of said slot means in said cavity means between said slot means and said conducting means and adjacent to an outer opening of said slot means, for reducing magnetic flux reaching said conducting means.
  10. 64. A power inductor comprising: a magnetic core material having first and second ends; an inner cavity arranged in said magnetic core material that extends from said first end to said second end; a conductor that passes through said cavity; and a slotted air gap arranged in said magnetic core material that extends from said first end to said second end, wherein said magnetic core material has a “C”-shaped cross section that defines an air gap and further including an eddy current reducing material that is located across said air gap and that has a permeability that is lower than said magnetic core material.
  11. 66. A method for reducing saturation in a power inductor, comprising: forming an inner cavity in a magnetic core material having first and second ends, wherein said inner cavity extends from said first end to said second end; passing a conductor through said cavity; providing a slotted air gap in said magnetic core material that extends from said first end to said second end; defining a “C”-shaped cross section and an air gap with said magnetic core material; and positioning an eddy current reducing material across said air gap, wherein said eddy current reducing material has a permeability that is lower than said magnetic core material.
  12. 68. A power inductor comprising: magnetic core means for conducting a magnetic field and having first and second ends; cavity means arranged in said magnetic core means that extends from said first end to said second end for receiving conducting means for conducting current; slot means arranged in said magnetic core means that extends from said first end to said second end for reducing saturation of said magnetic core means, wherein said magnetic core means has a “C”-shaped cross section that defines an air gap; and eddy current reducing means, that is located across said air gap, for reducing magnetic flux reaching said conducting means.

References Cited

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Other Publications

European Search Report for Appl. No. 04011558.6, 2 pages.
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Referenced By