Synchronous rectifier scheme for continuous conduction mode in primary side controlled fly-back converter
US12119755B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2022 |
| Grant date | Oct 15, 2024 |
| Priority date | — |
| Expiry date | Dec 18, 2042 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A primary-side-controlled fly-back converter is provided to eliminate cross-conduction between a power-switch (PS) on a primary side and a synchronous-rectifier (SR) on a secondary side when operating in continuous conduction mode (CCM). Generally, the converter includes a transformer having a primary coupled to a rectified AC input through the PS, and a secondary coupled to a DC output through the SR, the SR having a drain coupled to the secondary winding. A fly-back-controller includes a primary-controller operable to control a duty cycle of the PS, and a secondary-controller operable to turn OFF the SR when the PS turns ON in CCM. The secondary-controller includes a CCM zero-crossing-detector comparator having a first input coupled to the drain of the SR through a capacitor, and is operable to detect a sharp change in a drain voltage when the PS turns ON during CCM, and to output a signal to turn OFF the SR.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.