Driving circuit for light emitting diodes
US7592756B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2008 |
| Grant date | Sep 22, 2009 |
| Priority date | — |
| Expiry date | Mar 14, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A driving circuit includes a DC-to-DC voltage converter, a current source, a detector and a feedback control circuit. The DC-to-DC voltage converter has a switch and generates a driving voltage on first ends of the series of light emitting diodes, in which a magnitude of the driving voltage is correlated with conduction of the switch. The current source is coupled to second ends of the series of the light emitting diodes and provides driving currents flowing through the light emitting diodes. The detector generates a feedback voltage corresponding to a sum of voltages on the second ends of the series of the light emitting diodes. The feedback control circuit generates a first control signal which controls the conduction of the switch in response to the feedback voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.