| 摘要 |
PURPOSE:To obtain a Schmitt trigger circuit which is affected less by the change of the ambient conditions such as the power voltage and the like as well as the dispersion of the using MISFET's. CONSTITUTION:The Schmitt trigger circuit consists of inverter 1 to which input signal Vi is applied, inverter 2 which uses the output of inveter 1 as its input to form output Vo and MISFETT3 which is provided between the earth and the input terminal of inverter 2 to be controlled by output Vo. In such constitution, a selection is given to the threshold voltage of one side (T2) among the MISFET's forming inverter 1 of the first step with a higher amount equivalent to the voltage based on the Fermi level difference than the threshold voltage of the MOSFET featuring the same conducting channel of the other side. As a result, nearly a constant width of the hysteresis curve can be secured for the circuit irrespective of the change of various ambient conditions or the dispersion of the using MISFET's. |
