Generalized cancellation of inductor winding capacitance
US7548137B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 2007 |
| Grant date | Jun 16, 2009 |
| Priority date | — |
| Expiry date | Sep 6, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2001/0092
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An inductor device or filter such as an electromagnetic interference (EMI) filter which includes an inductor provides cancellation of parasitic capacitance of the inductor and extends high frequency performance of the inductor or filter by using an inductor network (a special case being split windings) and including capacitors to couple signals corresponding to those which are passed by the equivalent parallel capacitance of an inductor of a network of inductors such as in a multi-phase power supply of voltage converter to another inductor terminal, ground or an inductor in the ground return path. Cancellation of parasitic capacitance is provided for differential mode and common mode windings where the windings may be either inductively coupled or not. Forming the windings as a bifilar winding to increase coupling coefficient further improves performance and allows cancellation (as distinct from parasitic capacitance reduction) and avoidance of resonance in circuits in which an inductor is not permitted in the ground return path. Different inductance values and turns ratios of any or all inductors of the network, including multi-phase networks, may be accommodated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.