LTPS-TFT Pixel Circuit Compensating for TFT Threshold Voltage Shift and IR-Drop on the Power Line for AMOLED Displays

Abstract

We propose a new pixel design for the active matrix organic light-emitting diode (AMOLED) using low-temperature polycrystalline silicon thin-film transistors (LTPS-TFTs). The proposed pixel is composed of four switching TFTs, one driving TFT (DTFT), and one capacitor. The simulation results are performed by AIM-SPICE software. The error rate of OLED output current with (threshold voltage) variation (0.3 V) and power line drop by 1 V are improved to about 1.67% and 15%, respectively. Thus, the proposed pixel circuit can successfully overcome drawbacks suffered from DTFT threshold voltage deviation and IR-drop on power line.