Synchronous rectifying control method and circuit for isolated switching power supply
US9054592B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 2013 |
| Grant date | Jun 9, 2015 |
| Priority date | — |
| Expiry date | Dec 7, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed are synchronous rectifying control methods and circuits for an isolated switching power supply. In one embodiment, a method can include: (i) generating a ramp voltage based on a power terminal voltage, where the power terminal voltage includes a voltage between first and second power terminals of a synchronous rectifier in the isolated switching power supply; (ii) determining whether the power terminal voltage starts declining; (iii) comparing the ramp voltage to a threshold voltage when the power terminal voltage starts to decline, where the threshold voltage substantially matches a minimum conduction time of the synchronous rectifier; (iv) reducing the ramp voltage and controlling the synchronous rectifier in an off state when the ramp voltage is lower than the threshold voltage; and (v) reducing the ramp voltage and controlling the synchronous rectifier in on state when the ramp voltage is higher than the threshold voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.