AMOLED Pixel Circuit Using P-type LTPS TFTs Suitable for Low Refresh Rate Wearable Devices

This work presents a novel pixel circuit that can be applied to low refresh rate AMOLED displays, such as smartwatch displays, using LTPS TFTs. The circuit employs a leakage current balance method (LCBM) to address the issue of leakage currentunder low refresh rate conditions, enabling the pixel circuit to maintain uniform current even during a prolonged emission period. Furthermore, the anode of OLED is reset to prevent undesired emissions during programming stages, thus avoiding flicker. Simulation results of HSPICE simulator demonstrate that at a refresh rate of 15 Hz, the current fluctuations for high, medium, and low gray levels after 66.67 ms of emission time are 0.91%, 2.10%, and 9.29%, respectively.