Design of a IGZO TFT-based GOA circuit for external compensation pixel circuits

In this paper, a high-performance gate driver on array circuit (GOA) was designed with top-gate typed TFTs to provide switching signals for external compensation pixel circuits. To testify the function of this GOA circuit, the circuit was placed in a AMOLED display. It is turned out that the proposed GOA circuit exhibited stable output signals with pulse width from 60μs to 3.6ms. It is obviously that the pulse width of 3.6ms could meet the requirement of switching signals in external compensation pixel circuits. Moreover, the bottom gates bias of TFTs in GOA circuit could be adjustable by a external voltage source. Using a positive or negative bottom gate bias, the Vth of TFTs can be controllable to achieve a good output signal for GOA.