Decoder-Type Gate Driver Circuits Fabricated with Amorphous Silicon Thin-Film Transistors for Active Matrix Displays

Abstract

This paper quantitatively analyzes the signal integrity and device stability issues of gate driver circuits for active matrix displays integrated with hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs), and reveals that the clock-coupling noises and threshold voltage shift due to the DC gate bias in previous gate driver circuits can seriously affect the image quality. To resolve these problems, two types of decoder-based gate driver circuits have been proposed, that can completely avoid the floating output node to prevent the clock-coupling noises without applying the DC gate bias to all the TFTs used in the gate driver circuits. The performances and characteristics of the two proposed types of gate drivers will be discussed and compared, and the experimental results for the fabricated circuits will be presented. (c) 2011 The Japan Society of Applied Physics