Design of a PMOLED Driver Circuit to Compensate for the Non-Uniformity Problem in the Manufacturing Process

Abstract

In this paper, we propose a newly structured circuit that can compensate for the manufacturing process non-uniformity problem of data driver circuits for PMOLED's (passive matrix organic light emitting diode). A conventional data driver circuit for an OLED cannot compensate for the current deviation at the data driver circuit output terminal generated by MOS (metal oxide semiconductor) process changes, but the proposed data driver circuit can allow uniform current values to an OLED panel by calibrating the current deviation at the output terminal. The proposed circuit can minimize the deviation of the output current via a process change by connecting the circuit for the data output current to a common interconnect line by adding a switching transistor to the existing data output circuit. The circuit proposed in this paper was designed based on an OLED panel supporting QQVGA resolution, and the process used for driver circuit development was a 0.35um process. The experimental results shows the output current of the data driver circuit proposed here had a 1% range of error while a 7% range of severe change was demonstrated in the case of the previous data driver circuit. When using the proposed data driver circuit for an OLED, a high-definition OLED display can be realized and the circuit can be utilized for mobile display devices requiring high-quality display features.