Low Power Differential CMOS Schmitt Trigger with Adjustable Hysteresis

Abstract

This paper proposes a novel differential CMOS Schmitt trigger with adjustable hysteresis. The hysteresis of the proposed circuit is generated using cross-coupled pMOS or nMOS transistors, which can be tuned by engineering cross-coupled transistors current. By changing input voltage, the hysteresis window can also be adequately adjusted. Negative feedback has been introduced through CMOS differential amplifier which makes the circuit less sensitive to process, supply voltage and temperature (PVT) deviations. The proposed configuration uses TSMC 0.18 m CMOS technology with 1.8 V supply voltage. Simulation results show that the switching voltage of the circuit can be tuned for target applications.