Switch mode power supply controller with feedback signal decay sensing
US7944722B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 2009 |
| Grant date | May 17, 2011 |
| Priority date | — |
| Expiry date | Jun 20, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/33523
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This invention relates to SMPS controllers employing primary side sensing. We describe a system for identifying a knee point in a sensing waveform, at which the output voltage of the SMPS may be sampled accurately on the primary side. The system identifies the knee point by fitting a tangent to a portion of a power transformer voltage waveform, and samples the voltage waveform at the knee point to determine the SMPS output voltage. In preferred embodiments this technique is implemented using a decaying peak detector, providing a timing signal indicating detection of the knee point. Sample/hold and error amplifier circuits may be employed to achieve output voltage regulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.