A mixed-signal organic 1kHz comparator with low VT sensitivity on flexible plastic substrate

This paper presents a comparator that is designed in an organic electronics technology on a flexible plastic substrate with p-type organic thin-film transistors (p-OTFT) only. The comparator has a gain of 12 dB and works at a supply voltage of 20 V consuming 9 muA. At a clock frequency of 1 kHz the input sensitivity is 200 mV. The comparator is designed following a threshold-voltage V_T insensitive strategy for analog and mixed-signal design in a way to get round V_T variations of the pentacene based organic electronics technology. Measurements have been done in ambient environment. The circuits still function well after several weeks of exposure to ambient environment. This comparator can serve in organic smart sensor systems as an interface between analog sensor signals and digital circuitry or as a building block for more complex A-to-D converters.