A Compact Low-Voltage D-type Flip Flop Using Oxide TFTs and Its Application in Sequential Circuits

This brief presents a low-voltage D-type flip flop (D-FF) and its application in the sequential circuits, namely shift register (SR) and counter. These circuits were fabricated on a 30 $\mu \text{m}$ thick polymide substrate using single-gate indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs). The proposed D-FF is designed using only 18 n-type transistors. This circuit has shown almost 100% improvement in frequency of operation compared to state-of-the-artwork from measurements at a low power supply voltage of 4V. In addition, the resulting 6-bit SR and 6-bit counter show expected functionality with the proposed D-FF. These circuits would find potential applications in display drivers and flexible smart sensing systems.