Analog and Mixed Signal Circuit Design Techniques in Flexible Unipolar a-IGZO TFT Technology: Challenges and Recent Trends

Advancements in the field of flexible electronics have enabled many novel applications such as wearables, flexible large-area displays, and textile-based sensor systems. A widely used semiconductor material for flexible electronics is amorphous indium gallium zinc oxide (a-IGZO). When compared to other semiconductors suitable for flexible technologies, this material is attractive for its higher mobility, better bias stability and improved uniformity. This paper presents an overview of current trends in analog and mixed signal circuit design and in architectures for a-IGZO TFT based sensor systems. We highlight the specific design challenges associated with the main sub-blocks found in sensors and bio-signal acquisition systems based on a-IGZO TFT technologies: front-end amplifiers and data converters. We then present an overview of several state-of-the-art sensor systems based on a-IGZO TFTs and their applications. Finally, conclusions are drawn, and a roadmap for the future development of analog and mixed signal circuit design in a-IGZO TFT is presented.