Light-emitting diode (LED) current balance circuit
US8525436B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 2010 |
| Grant date | Sep 3, 2013 |
| Priority date | — |
| Expiry date | Oct 25, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/347
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A light-emitting diode (LED) current balance circuit includes a reference current generator, a current mirror and a voltage compensation circuit. The reference current generator provides a reference current robust against disturbance in a supply voltage applied to the reference current generator. The current mirror generates, according to the reference current, sink currents to bias lightbars and employs a structure to reduce the influence of unmatched transistors on the sink currents to stabilize and clamp currents through the lightbar. The voltage compensation circuit detects the voltages across the lightbars to compensate the lightbars having various forward voltages to ensure the turn-on of all lightbars and to effectively balance the currents through the lightbars. Therefore, a simpler circuit architecture is employed which does not need a specific-purpose LED controller to be cheaper and more competitive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.