Compensation Pixel Circuit Based on LTPS TFTs to Improve Effect of Leakage Current for AMOLED Displays with Low Frame Rate

摘要

This paper proposes a new pixel circuit for active matrix organic light-emitting diode displays with low frame rate. The proposed circuit can compensate for the threshold voltage variations, VDD current-resistant drops, and the effect of high leakage current of low-temperature polycrystalline silicon thin-film transistors to supply stable and uniform OLED driving currents. The simulation results show that the relative current error rates are less than 4.5% under the circumstances of ± 0.5 V threshold voltage variations and 0.5 V VDD current-resistance drops. Moreover, the distortions of the gate voltage of the driving TFTs are smaller than 1.4 V under a 15 Hz frame rate operation compared with the 4T2C circuit, proving the leakage current compensation capability for the proposed pixel circuit.