Symmetric split planar transformer
US11631523B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2020 |
| Grant date | Apr 18, 2023 |
| Priority date | — |
| Expiry date | Aug 25, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F2038/146
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed herein is a symmetric split planar transformer in the context of a DC-DC isolated converter. The symmetric split planar transformer reduces or eliminates asymmetry in the distribution of parasitic capacitance across the isolation barrier going from one end to another end of a primary coil, and as a result, undesirable electromagnetic interference (EMI) due to common mode dipole emission across the isolation barrier may be reduced. In some embodiments, the primary winding is split into at least a first coil and a second coil, each occupying a different area side-by-side on a substrate. The transformer is symmetric in the sense that a capacitive coupling of the first coil to a secondary winding is the same as a capacitive coupling of the second coil to the secondary winding, such that common mode EMI may be reduced. Each coil may include stacked spiral coil portions in multiple metal planes to increase inductive density across the isolation barrier. Furthermore, in some embodiments the first and second coils may have opposite spiral directions such that far field radiation effect from the transformer may be reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.