Switching control circuits with valley lock for power converters
US8482937B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 2010 |
| Grant date | Jul 9, 2013 |
| Priority date | — |
| Expiry date | Feb 14, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A switching control circuit for a switching power converter is provided. The switching control circuit is coupled to a switching device and an auxiliary winding of a transformer. The switching control circuit includes a valley detecting circuit, a valley lock circuit, and a PWM circuit. The valley detecting circuit is coupled to receive a reflected voltage signal from the auxiliary winding of the transformer for outputting a control signal in response to the reflected voltage signal. The valley lock circuit is coupled to receive the control signal for outputting a judging signal in response to the control signal during a first period and a second period following the first period. The PWM circuit outputs a switching signal in response to the judging signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.