LED driving circuit, LED driving control unit and transistor switch module thereof
US8461769B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2009 |
| Grant date | Jun 11, 2013 |
| Priority date | — |
| Expiry date | Sep 23, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An LED driving circuit is used for dimming by switching between an operating current and a maintaining current or by voltage clamping of a source/drain of MOSFET that is coupled to the LED module. When the LED module is dimmed off, the voltage across the LED module can be kept at a value around a lighting threshold voltage of the LED module that is a minimum voltage for lighting the LED module. Therefore, a voltage difference between the drain and the source of MOSFET coupled to the LED module is smaller than that in the conventional arts. Hence, a withstand voltage of MOSFET can be reduced, and cost of the LED driving circuit as well as the power consumption of MOSFET can be lessened, thereby improving integral efficiency of the circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.