Controlling circuit for an LED driver and controlling method thereof
US9018855B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 14, 2014 |
| Grant date | Apr 28, 2015 |
| Priority date | — |
| Expiry date | May 14, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/385
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a controlling circuit and controlling method for an LED driver implemented as a flyback topology. The controlling circuit may be at a primary side of a transformer of the LED driver, and include a sampling circuit, an on time sensing circuit of an output diode, a regulating signal generator, and a PWM controller. The sampling circuit may generate a sampling signal indicating output current by sampling at the primary transformer side. The on time sensing circuit can detect an on time of the output diode. The regulating signal generator can generate a regulating signal by regulating the sampling signal, a voltage reference, and the on time of the output diode. The PWM controller may generate a controlling signal to control operation of a switching device of the LED driver to maintain a substantially constant output current in accordance with the regulating signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.