Gate Driver on Array With Multiple Outputs and Variable Pulse Widths for Low-Temperature Polysilicon and Oxide (LTPO) TFTs Driven AMOLED Displays

A gate driver on array (GOA) circuit was proposed for low-temperature polysilicon and oxide (LTPO) thin-film transistor (TFT) hybrid-driven active matrix organic light-emitting diode (AMOLED) displays with both high and low refresh rate operation. The GOA generates multiple types of scanning signals by reusing shift registers so that three signal pulses are output parallelly within a single stage to scan p- and n-type switching TFTs and emission TFT of the AMOLED pixels, respectively, leading to a 30% reduction in the layout area. Furthermore, the pulse-width of the scan signals for the emission TFT can be programed simply by changing the number of input pulses to vary refresh rates. The fabricated GOAs work well even with the pulse width reduced to $2.9 \mathbf {\mu }\text{s}$ .