Synchronous rectifier controller to eliminate reverse current flow in a DC/DC converter output
US6618274B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 2001 |
| Grant date | Sep 9, 2003 |
| Priority date | — |
| Expiry date | Oct 9, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control scheme for a synchronous rectifier converter that avoids disabling the synchronous rectifiers entirely. Rather than disable the synchronous rectifier altogether to stop the flow of reverse current in light-load, startup, or shutdown conditions, the duty cycle of the synchronous rectifier is modified such that forward current is always allowed to flow through the synchronous rectifier, but the synchronous rectifier is turned off before the reverse current flow reaches a pre-determined level. This is accomplished by operating the converter in a partially synchronous mode of operation during light-load, startup, or shutdown conditions. Whether the circuit is in a light-load, startup, or shutdown condition is determined by a circuit characteristic of the converter that is sensed by the controller, such as average output current. The desired changeover point from fully-synchronous mode to the partially synchronous mode is set to a predetermined level of output current for the converter. The predetermined level is set based on the particular power system in which the invention is implemented. For example, this level can be based on the amount of reverse current that would disru…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.