A 38<i>μ</i>m-Pitch, 3-Output Gate Driver Using Low-Temperature Poly-Si Oxide TFTs for High Resolution Display
Junyeong Kim, Myeonggi Jeong, Byeonggwan Kim, Jin Jang
Abstract
We report a 38 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -pitch gate driver with three outputs using low-temperature poly-Si oxide (LTPO) thin-film transistors (TFTs) for ultra-high definition (UHD) display. A single stage of the proposed gate driver circuit consists of ten TFTs, six p-type low-temperature poly-Si (LTPS) and four n-type amorphous InGaZnO (a-IGZO) TFTs for three outputs. Three clock (CLK) signals are used for three outputs in one stage. The fabricated gate driver circuit, using the depletion mode a-IGZO TFTs with threshold voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{V}_{{{\mathrm {TH}}}}$ </tex-math></inline-formula> ) of −3.5 V, successfully operates with a pulse width of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1~\mu \text{s}$ </tex-math></inline-formula> . This can be used for 8k4k resolution display operated at refresh rate of 240 Hz. The power consumption can be as low as 9.4 mW at 4k2k ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3840\times2160$ </tex-math></inline-formula> ) resolution operated at 120 Hz. The proposed gate driver therefore can be utilized for UHD display with LTPO TFT backplane.