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P‐39: A 1.05% Sensing Error Current Comparator for AMOLED Displays with External Compensation
Author(s) -
Bai Wenlong,
Yi Shuiping,
Lam Hing-Mo,
Zhang Min,
Zhang Shengdong,
Jiao Hailong
Publication year - 2020
Publication title -
sid symposium digest of technical papers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.351
H-Index - 44
eISSN - 2168-0159
pISSN - 0097-966X
DOI - 10.1002/sdtp.14170
Subject(s) - amoled , comparator , oled , materials science , optoelectronics , compensation (psychology) , thin film transistor , cmos , diode , threshold voltage , electronic circuit , transistor , active matrix , current (fluid) , voltage , electrical engineering , electronic engineering , layer (electronics) , engineering , nanotechnology , psychology , psychoanalysis
External compensation is an effective scheme to adapt the threshold voltage variations of the driving Thin‐Film Transistors (TFTs) and the deterioration of the Organic Light‐Emitting Diodes (OLEDs) in pixel circuits of Active‐Matrix Organic Light‐Emitting Diode (AMOLED) display systems. In this paper, an accurate current comparator is proposed to sense the difference between the current trickling through the OLED and the reference current, so that the deterioration and variations of TFTs and OLEDs in the AMOLED pixel circuits can be detected and compensated effectively. The proposed current comparator is demonstrated in a source driver chip for AMOLED panel with external compensation and fabricated in a 0.25‐μm high‐voltage CMOS technology. The sensing accuracy of the proposed current comparator is less than 5.3 nA by chip measurement with 500 nA reference current. Furthermore, the sensing error of the proposed current comparator is lower than 1.05%.