A Charge-Pump-Based Current Feedback Method for AMOLED Displays

Author

Chih-Lung Lin ; Fu-Chieh Chang ; Po-Chun Lai ; Po-Syun Chen ; Wen-Yen Chang

Author_Institution

Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan

Volume

9

Issue

10

fYear

2013

fDate

Oct. 2013

Firstpage

783

Lastpage

786

Abstract

This work presents a new external driving scheme that uses the current feedback method with a 3T1C pixel circuit. The proposed circuit provides a stable OLED driving current by compensating for the threshold voltage shift of amorphous-silicon thin-film transistors (a-Si TFTs). For fabricated a-Si TFTs and the 0.35 μm CMOS process associated with the proposed driving scheme, measurements reveal that the normalized OLED current degradation is less than 5% after 60 hours of operation at 60°C. Moreover, for a data line load of 1.69 K Ω/110 pF, the relative error rates between data currents and OLED currents are less than 4% within a settling time of 19 μs.

Keywords

CMOS integrated circuits; LED displays; amorphous semiconductors; charge pump circuits; circuit feedback; elemental semiconductors; organic light emitting diodes; silicon; thin film transistors; 3T1C pixel circuit; AMOLED displays; CMOS; Si; amorphous-silicon thin-film transistors; charge-pump-based current feedback method; external driving scheme; size 0.35 mum; temperature 60 degC; threshold voltage shift; time 19 mus; time 60 hour; Active matrix organic light emitting diodes; CMOS integrated circuits; Charge pumps; Logic gates; Thin film transistors; Threshold voltage; Charge pump; external driving circuit; pixel circuit;

fLanguage

English

Journal_Title

Display Technology, Journal of

Publisher

ieee

ISSN

1551-319X

Type

jour

DOI

10.1109/JDT.2013.2279885

Filename

6588572