Resistive Schmitt-Trigger Logic and High-Performance Digital Cell Library for Flexible Organic Thin-Film Transistor Technologies

Abstract

<p>A resistive Schmitt-trigger (RST) logic is proposed. Based on this architecture, a digital cell library was designed, and basic logic-gate architectures, ring oscillators, edge-sensitive D-type flip-flops and a pad-driver cell were fabricated using low-voltage p-channel organic thin-film transistors (TFT) and integrated thin-film carbon resistors on flexible polymeric substrates. Theoretical analysis and experimental characterization of the RST logic architecture indicate improved stability against device-parameter mismatch and charge-carrier-mobility degradation. A small-signal gain of 83 dB and a noise margin of 92 % of half the supply voltage have been measured. Owing to the intrinsic positive-feedback loop of the RST logic, the design of the D-flip-flop enables a substantially smaller footprint and a considerably lower energy dissipation compared to previously reported unipolar organic-TFT-based D-flip-flops.</p>