Ternary Schmitt circuit based on neuron-MOS transistor

A novel voltage-mode CMOS ternary 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 ternary signal are controlled by the outputs of the literal circuits to realize two hysteresis loops of ternary Schmitt circuit. The benefit of the proposed ternary Schmitt trigger is that the circuit can be fabricated by standard CMOS process with a 2-ploy layer, instead of the multi-level ion implantation applied in the conventional voltage-mode multiple-valued circuits. The two hysteresis loops are fully adjustable by sizing the ratio of capacitive coupling coefficients. Besides, as the variable threshold voltage can be achieved easily in neuron-MOS literal circuits, the proposed ternary Schmitt trigger has a simple structure. The effectiveness of the proposed ternary 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%.