Voltage-Mode Multi-Valued Schmitt Trigger with Neuron-MOS Transistors

A novel design scheme of multiple-valued Schmitt trigger using neuron-MOS transistors is presented. By controlling the voltages of the multiple-input gates, the neuron-MOS literal circuits with hysteresis characteristics are firstly designed. Then, the transmission switches used to pass quaternary signal are controlled by the outputs of these literal circuits to realize three hysteresis loops of quaternary Schmitt circuit. The benefit of the proposed quaternary Schmitt trigger is that the circuit can be fabricated by standard CMOS process with a 2-ploy layer. The three hysteresis loops are fully adjustable by sizing the ratio of capacitive coupling coefficients. The effectiveness of the proposed Schmitt trigger has been validated by HSPICE simulation results with TSMC 0.35μm 2-ploy 4-metal CMOS technology, and the discrepancy of hysteresis values between the simulated and theoretical results is smaller than 6%.