Neuron-MOS Based Schmitt Trigger with Controllable Hysteresis

A novel Schmitt trigger with controllable hysteresis using neuron-MOS transistors is presented. By selecting the ratio of capacitive coupling coefficients, a Schmitt trigger with different hysteresis characteristics can be achieved. By only varying the external input control signals, the hysteresis window can be conveniently moved without changing its width. The proposed Schmitt trigger has considerable simpler structure requiring only two neuron-MOS transistors and one CMOS inverter. The proposed Schmitt circuit is validated by HSPICE simulations with TSMC 0.35 mu m 2-ploy 4-metal CMOS technology, and the discrepancy of hysteresis values between the simulated and theoretical results is smaller than 5%.