Switching power supply device and switching power supply control circuit
US8243473B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 2009 |
| Grant date | Aug 14, 2012 |
| Priority date | — |
| Expiry date | Oct 22, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention provides a switching power supply device which can detect a light load state on a pulse-by-pulse basis without worsening power efficiency. In a synchronous control circuit, for each timing of the turning-on of main switching elements, the delay time Tdif of the conduction timing of internal diodes Ds determined according to the magnitude of the load LD is detected by a comparator, a reference time pulse Tsrs having a prescribed time width is generated by a load judgment circuit, and the logical product of the two is generated by an AND circuit. By this means, the load is regarded as being a light load when the delay time Tdif is longer than the reference time pulse Tsrs, and the synchronous rectification MOSFETs Qs are not turned on.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.