LED driver and circuit for controlling a power switch to provide a driving voltage to at least one LED
US7768212B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 2008 |
| Grant date | Aug 3, 2010 |
| Priority date | — |
| Expiry date | Mar 14, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An LED driver circuit and its control circuit for controlling its power switch are provided. The LED driver includes a switch, a PWM controller, a current source and a signal controller. The switch has a first end outputting a driving voltage to at least one LED. The PWM controller provides a PWM signal. The current source provides a driving current flowing through the LED when a dimming control signal is asserted. The signal controller turns off the switch when the dimming control signal is de-asserted and relays the PWM signal from the PWM controller to the switch so that the switch is controlled by the PWM signal when the dimming control signal is asserted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.