Multi-turn inductors

• US 7,994,888 B2
• Filed: 12/21/2009
• Issued: 08/09/2011
• Est. Priority Date: 12/21/2009
• Status: Active Grant

• Current Assignee: Volterra Semiconductor Corporation (Analog Devices, Inc.)
• Original Assignee: Volterra Semiconductor Corporation (Analog Devices, Inc.)
• Inventors: Ikriannikov, Alexandr
• Primary Examiner(s): Mai; Anh
• Assistant Examiner(s): LIAN, MANGTIN B.
• Application Number:
  US12/643,957
• Publication Number:
  US 20110148559A1
• Time in Patent Office: 596 Days
• Field of Search: None
• US Class Current: 336/192
• CPC Class Codes: H01F 2038/026 non-linear inductive arrangements for converters, e.g. with additional windings
• CPC Class Codes: H01F 27/027 specially adapted for combination of signal type inductors or transformers with electronic circuits, e.g. mounting on printed circuit boards
• CPC Class Codes: H01F 27/2847 Sheets; Strips H01F27/2866 takes precedence
• CPC Class Codes: H01F 3/08 made from powder powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel

Abstract

A multi-winding inductor includes a first foil winding and a second foil winding. One end of the first foil winding extends from a first side of the core and wraps under the core to form a solder tab under the core. One end of the second foil winding extends from a second side of the core and wraps under the core to form another solder tab under the core. Respective portions of each solder tab are laterally adjacent under the magnetic core. A coupled inductor includes a magnetic core including a first and a second end magnetic element and a plurality of connecting magnetic elements disposed between and connecting the first and second end magnetic elements. A respective first and second single turn foil winding is wound at least partially around each connecting magnetic element. Each foil winding has two ends forming respective solder tabs.

Claims

1. A multi-winding inductor, comprising:

a magnetic core having a first side opposite a second side;

a first foil winding passing through the magnetic core from the first side to the second side, a first end of the first foil winding extending from the first side of the core and wrapping under the core to form a first solder tab under the core suitable for surface mount soldering to a printed circuit board, a second end of the first foil winding extending from the second side of the core to form a second solder tab suitable for surface mount soldering to a printed circuit board; and

a second foil winding passing through the magnetic core from the first side to the second side, a first end of the second foil winding extending from the second side of the core and wrapping under the core to form a third solder tab under the core suitable for surface mount soldering to a printed circuit board, a second end of the second foil winding extending from the first side of the core to form a fourth solder tab suitable for surface mount soldering to a printed circuit board;

a portion of the first solder tab being laterally adjacent to a portion of the third solder tab under the magnetic core.

2. The inductor of claim 1, the second and fourth solder tabs being disposed under the core, a portion of the second solder tab being laterally adjacent to a portion of the first solder tab under the core, and a portion of the fourth solder tab being laterally adjacent to a portion of the third solder tab under the magnetic core.

3. The inductor of claim 1, further comprising a third foil winding passing through the magnetic core from the first side to the second side, a first end of the third foil winding extending from the second side of the core and wrapping under the core to form a fifth solder tab under the core suitable for surface mount soldering to a printed circuit board, a second end of the third foil winding extending from the first side of the core to form a sixth solder tab, the fourth solder tab being disposed under the core, a portion of the fourth solder tab being laterally adjacent to a portion of the fifth solder tab under the magnetic core.

4. The inductor of claim 3, a portion of the first solder tab comprising at least twenty percent of a length of the first solder tab being laterally adjacent to a portion of the third solder tab comprising at least twenty percent of a length of the third solder tab;

and a portion of the fourth solder tab comprising at least twenty percent of a length of the fourth solder tab being laterally adjacent to a portion of the fifth solder tab comprising at least twenty percent of a length of the fifth solder tab.

5. The inductor of claim 1, further comprising:

a third foil winding passing through the magnetic core from the first side to the second side, a first end of the third foil winding extending from the first side of the core and wrapping under the core to form a fifth solder tab under the core suitable for surface mount soldering to a printed circuit board, a second end of the third foil winding extending from the second side of the core to form a sixth solder tab suitable for surface mount soldering to a printed circuit board; and

a fourth foil winding passing through the magnetic core from the first side to the second side, a first end of the fourth foil winding extending from the second side of the core and wrapping under the core to form a seventh solder tab under the core suitable for surface mount soldering to a printed circuit board, a second end of the fourth foil winding extending from the first side of the core to form an eighth solder tab suitable for surface mount soldering to a printed circuit board;

a portion of the fifth solder tab being laterally adjacent to a portion of the seventh solder tab under the magnetic core.

6. The inductor of claim 5, a portion of the first solder tab comprising at least twenty percent of a length of the first solder tab being laterally adjacent to a portion of the third solder tab comprising at least twenty percent of a length of the third solder tab;

and a portion of the fifth solder tab comprising at least twenty percent of a length of the fifth solder tab being laterally adjacent to a portion of the seventh solder tab comprising at least twenty percent of a length of the seventh solder tab.

7. The inductor of claim 5, further comprising a first printed circuit board, the first and third solder tabs being electrically connected together by a first trace of the first printed circuit board, and the fifth and seventh solder tabs being electrically connected together by a second trace of the first printed circuit board trace.

8. The inductor of claim 1, further comprising a first printed circuit board, the first and third solder tabs being electrically connected together by a printed circuit board trace of the first printed circuit board.

9. The inductor of claim 1, the first and second windings extending through the core without forming any turns.

10. The inductor of claim 9, the core having a rectangular shape.

11. The inductor of claim 1, a portion of the first solder tab comprising at least twenty percent of a length of the first solder tab being laterally adjacent to a portion of the third solder tab comprising at least twenty percent of a length of the third solder tab.

12. The inductor of claim 1, a portion of the first solder tab comprising at least forty percent of a length of the first solder tab being laterally adjacent to a portion of the third solder tab comprising at least forty percent of a length of the third solder tab.

13. The inductor of claim 8, the first and second foil windings and the printed circuit board trace collectively forming a single winding having two turns.