This paper presents a sub-threshold differential CMOS Schmitt trigger with tunable hysteresis, which can be used to enhance the noise immunity of low-power electronic systems. By exploiting the body bias technique to the positive feedback transistors, the hysteresis of the proposed Schmitt trigger is generated, and it can be adjusted by the applied bias voltage to the bulk terminal of the utilized PMOS transistors. The principle of operation and the main formulas of the proposed circuit are discussed. The circuit is designed in a 0.18-μm standard CMOS process with a 0.6 V power supply. Post-layout simulation results show that the hysteresis width of the Schmitt trigger can be adjusted from 45.5 mV to 162 mV where the ratio of the hysteresis width variation to supply voltage is 19.4%. This circuit consumes 10.52 × 7.91 μm2 of silicon area, and its power consumption is only 1.38 µW, which makes it a suitable candidate for low-power applications such as portable electronic, biomedical, and bio-implantable systems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.