Ultra-Low Power, Emission Gate Driver With Pulse Width Modulation Using Low-Temperature Poly-Si Oxide Thin-Film Transistors

Abstract

We report a novel emission gate driver using low- temperature poly-Si oxide (LTPO) thin-film transistors (TFTs). The proposed circuit consists of eight p-type low-temperature poly-Si (LTPS) and four n-type amorphous InGaZnO (a-IGZO) TFTs. The output pulse width is adjustable by changing the position of starting control signal which has constant pulse width without additional clock signals. The emission gate driver releases the output signals with various duty ratios. Excellent gate driving performance is achieved from the LTPO emission gate driver, although the a-IGZO TFTs have the threshold voltage of −5.5 V. In addition, the power consumption is as low as 5.98 mW in case of 80 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\boldsymbol {\mu }\text{s}$ </tex-math></inline-formula> pulse, 10 times of gate pulse, at refresh rate of 120 Hz with full high-definition ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1920\times1080$ </tex-math></inline-formula> ) for active-matrix organic light- emitting diode (AMOLED) display.