Differential CMOS Schmitt trigger with tunable hysteresis

Abstract

This letter presents a new differential Schmitt trigger with tunable hysteresis. The hysteresis is generated using a cross-coupled inverter pair. The amount of hysteresis can be adjusted by varying the current of the symmetrical load. The proposed Schmitt trigger has been designed in TSMC-0.18 μm 1.8 V CMOS technology and analyzed using Spectre from Cadence Design Systems with BSIM3V3 device models. Simulation results demonstrate that the triggering voltage of the Schmitt trigger can be adjusted from 0.95 to 1.35 V approximately.