LED driver and power control circuit with spread spectrum frequency modulation function and display panel using the same
US8076868B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 30, 2009 |
| Grant date | Dec 13, 2011 |
| Priority date | — |
| Expiry date | Jun 10, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention relates to an LED driver, power control circuit and display panel using the same. The LED driver has the function of spread spectrum frequency modulation (SSFM). The circuit topology of the driver includes a power converter, an error amplifier, a feedback circuit, a saw-tooth generator and a driving circuit. The present invention adds the SSFM circuit in the saw-tooth generator to generate a time variant current according to time variant function, so that the saw-tooth wave could be changed by the time variant current as mentioned above. Therefore, the frequency of the driving pulse generated by the LED driver will be varied as time. As the result, the reduction of the electro-magnetic interference (EMI) can be achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.