High dimming ratio LED drive circuit
US7615974B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 8, 2007 |
| Grant date | Nov 10, 2009 |
| Priority date | — |
| Expiry date | May 5, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/3725
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method and an apparatus for controlling average current by pulse modulating an output current. The apparatus includes a constant-on-time switching regulator. During the pulse modulation on-time, an output voltage is regulated at a level corresponding to a defined value of a corresponding output current. A control signal is provided to indicate an adjustment to the output voltage that enables regulation of the output current to the defined value. During the pulse modulation off-time, the output voltage is maintained at the level that substantially corresponds to the defined value of the output current during the pulse-modulation on-time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.