Offline synchronous rectifying circuit with sense transistor for resonant switching power converter
US7911813B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 2008 |
| Grant date | Mar 22, 2011 |
| Priority date | — |
| Expiry date | Oct 14, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A synchronous rectifying circuit of a resonant switching power converter is provided to improve the efficiency. The synchronous rectifying circuit includes a power transistor and a diode connected to a transformer and an output ground of the power converter for rectifying. A sense transistor is coupled to the power transistor for generating a mirror current correlated to a current of the power transistor. A controller generates a driving signal to control the power transistor in response to a switching-current signal. A current-sense device is coupled to the sense transistor for generating the switching-current signal in response to the mirror current. The controller enables the driving signal to turn on the power transistor once the diode is forwardly biased. The controller generates a reset signal to disable the driving signal and turn off the power transistor once the switching-current signal is lower than a threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.