A Low-Power Fully Dynamic Latched Comparator Using Flexible Oxide TFT Technology

This letter presents a novel low-power, fully dynamic, latched comparator using only n-type, single-gate amorphous-Indium-Gallium-Zinc-Oxide thin-film transistors (a-IGZO TFTs) on a 27μm thick polyimide substrate. This circuit demonstrates a stable performance up to an input signal frequency of 15kHz with 1MHz clock. By employing a pseudo-CMOS bootstrapped load, it achieved an output voltage swing of around 90%, an input-referred offset and noise voltages of 28mV and 14mV, respectively from measurements. In addition, it can reliably detect a minimum differential input voltage of 50mV at a VDD of 4V, while consuming only 8μW power. Therefore, this design is well-suited in biomedical wearable devices which typically needs low-power.