| 摘要 |
PURPOSE:To obtain an input circuit having a high thershold voltage against the fluctuation in threshold voltage, by using a voltage division circuit comprising series connection of an IGFET to the gate to which an input signal is connected, and of a plurality of IGFETs of diode connection, as the input circuit of an inverter. CONSTITUTION:When an input signal at an input I is smaller than the sum of the threshold voltage of an enhancement E-IGFET E01 and a forward threshold voltage of a diode circuit comprising E-IGFETs E01-E06, since no current flows to the diode circuit, the input of the inverter consisting of a depletion type D-IGFETD02 and E-IGFET07 is a ground potential and the output gpes to a VCC potential, and the output of an inverter comprising D03 and E08 is the ground potential. When the voltage of the input I is increased and exceeds the sum of threhshold voltages of the E01-E06, a current flows to this circuit. When a voltage dividing a voltage VPP with the resistance of the circuit and the resistance of the D-IGFETD01 exceeds the threshold value of the inverters D02, E07, the output potential of the inverters D03 and E08 goes to the voltage VCC. |
