Low-Power Bootstrapped Rail-to-Rail Logic Gates for Thin-Film Applications

This paper presents low-power rail-to-rail output inverter and logic gates with only n-channel transistors. The proposed circuits with two capacitive-coupled stages and feedback are capable of reducing the direct path current substantially, essentially for antenna powered and mobile applications, while ensuring the full swing output. The presented simulation and measurement results are based on modeling and experimental characterization of low-temperature hydrogenated back-channel etched amorphous silicon thin-film transistors (a-Si:H TFT) and indium-gallium-zinc-oxide (IGZO) TFTs. The insensitivity of the design to the variation of the on-voltage of IGZO TFT technology is demonstrated.