LED backlight driving circuit for LCD panels
US9439259B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 2012 |
| Grant date | Sep 6, 2016 |
| Priority date | — |
| Expiry date | Apr 4, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A current drive circuit capable of reducing the influence of temperature variation or individual deviation is provided. An output transistor is a PNP bipolar transistor, and has an emitter connected to a cathode of an LED string. A current control resistor is disposed between a collector of the output transistor and a ground terminal. An output terminal of an error amplifier is connected to a base of the output transistor, a first input terminal of the error amplifier is connected to a connection point of the output transistor and the current control resistor, and a reference voltage is applied to a second input terminal of the error amplifier. The error amplifier enables a sink current sunk from the output terminal to flow to the current control resistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.