LED driver circuits with current envelope control
US8791648B2 · kind B2 · utility
1Cited by
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18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 10, 2012 |
| Grant date | Jul 29, 2014 |
| Priority date | — |
| Expiry date | Sep 6, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/39
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A light emitting diode (LED) driver circuit controls switching of an output transistor. The LED driver circuit monitors inductor current flowing through an output inductor that is coupled to one or more LEDs. In response to detecting that the inductor current has reached a peak value, the LED driver circuit switches OFF the output transistor. The LED driver circuit switches ON the output transistor in response to detecting zero crossing of the inductor current. The LED driver circuit may detect zero crossing of the inductor current from a gate voltage of the output transistor by detecting for a negative spike.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.