TRANSFORMER WITH EFFECTIVE HIGH TURN RATIO

• US 20080284553A1
• Filed: 07/19/2007
• Published: 11/20/2008
• Est. Priority Date: 05/18/2007
• Status: Active Grant

• Current Assignee: Globalfoundries Singapore Pte Limited (GlobalFoundries, Inc.), Nanyang Technological University
• Original Assignee: Chartered Semiconductor Manufacturing Incorporated (Mamoura Diversified Global Holding PJSC), Nanyang Technological University
• Inventors: LIM, Chee Chong, CHEW, Kok Wai, LIM, Suh Fei, CHAN, Lap, DO, Manh Anh, YEO, Kiat Seng
• Granted Patent: US 8,242,872 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 2017/0073 with a special conductive pattern, e.g. flat spiral
• CPC Class Codes: H01F 27/006 with special arrangement or spacing of turns of the winding(s), e.g. to produce desired self-resonance
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

Embodiments of the invention provide a transformer comprising: a first coil element having a transverse axis along a transverse direction, the first coil element having p turns where p is greater than or equal to 1; and a second coil element having a transverse axis generally parallel to the transverse axis of the first coil element, the second coil element having n turns, where n is greater than or equal to 5 p; wherein the first and second coil elements are arranged to provide electromagnetic coupling between the coil elements along a portion of a length of the second coil element in both a transverse direction parallel to the transverse axes and a lateral direction, wherein the lateral direction is a direction normal to the transverse axes.

Claims

1. A transformer comprising:

a first coil element having a transverse axis along a transverse direction, the first coil element having p turns where p is greater than or equal to 1; and

a second coil element having a transverse axis generally parallel to the transverse axis of the first coil element, the second coil element having n turns, where n is greater than or equal to 5 p,

wherein the first and second coil elements are arranged to provide electromagnetic coupling between the coil elements along a portion of a length of the second coil element in both a transverse direction substantially parallel to said transverse axes and a lateral direction, wherein the lateral direction is a direction substantially normal to said transverse axes.

2. The transformer of claim 1 wherein p is an integer.

3. The transformer of claim 1 wherein n is an integer.

4. The transformer of claim 2 wherein p=1 to 30.

5. The transformer of claim 3 wherein n=5 p to 1000 p

6. The transformer of claim 3 wherein n=10 p to 500 p

7. The transformer of claim 1 wherein the first and second coil elements are substantially coaxial.

8. The transformer of claim 1 wherein a first portion of the first coil element is adjacent to at least a portion of an outer peripheral edge of the second coil element, the first portion of the first coil element being arranged to provide electromagnetic coupling in a substantially lateral direction between the first and second coil elements.

9. The transformer of claim 1 wherein a second portion of the first coil element is adjacent to at least a portion of an inner peripheral edge of the second coil element, the second portion of the first coil element being arranged to provide electromagnetic coupling in a substantially lateral direction between the first and second coil elements.

10. The transformer of claim 1 wherein a third portion of the first coil element is mutually spaced apart from at least a portion of the second coil element along said transverse direction, the third portion of the first coil element being arranged to provide electromagnetic coupling in a substantially transverse direction between the first and second coil elements.

11. The transformer of claim 8 wherein the first portion of the first coil element comprises a skirt portion extending from a third portion of the first coil element.

12. The transformer of claim 9 wherein the second portion of the first coil element comprises a skirt portion extending from a third portion of the first coil element.

13. The transformer of claim 10 wherein the third portion of the first coil element comprises a plurality of concentric tracks.

14. The transformer of claim 10 wherein the third portion of the first coil element comprises a continuous planar sheet.

15. The transformer of claim 10 wherein a fourth portion of the first coil element is mutually spaced apart from at least a portion of the second coil element along said transverse direction on an opposite side of the secondary coil to said third portion of the first coil element.

16. A transformer comprising:

a first coil formed in a substrate; and

a second coil formed in the substrate, the second coil includes a plurality of n turns, wherein the first coil surrounds the second coil to produce mutual inductance between the coils in multi-lateral directions to increase the effective turn ratio of the transformer.

17. A method of fabricating a transformer comprising:

providing a first coil element having a transverse axis, the first coil element having p turns wherein p is greater than or equal to 1; and

providing a second coil element having a transverse axis substantially parallel to said transverse axis of the first coil element, the second coil element having n turns, where n is greater than or equal to 5 p,

wherein the first and second coil elements are formed to provide electromagnetic coupling between the coil elements along a portion of a length of the second coil element in both a transverse direction substantially parallel to said transverse axes and a lateral direction substantially normal to said transverse axes.

18. The method of claim 17 wherein p is an integer.

19. The method of claim 17 wherein n is an integer.

20. The method of claim 18 wherein p=1 to 30.

21. The method of claim 19 wherein n=5 p to 1000 p.

22. The method of claim 19 wherein n=10 p to 500 p.