| 摘要 |
PURPOSE:To interrupt a FET by a control voltage smaller than a peak value of an input signal by connecting a capacitor between a control electrode and an output electrode of a field effect transistor (TR) FET, a series circuit comprising a control current blocking diode and a resistor between the control electrode and a control terminal and an impedance element between the resistor and an input electrode. CONSTITUTION:A control voltage +Vp is impressed to a control terminal 11 and the input signal from the input electrode 4 via the impedance element 12 and the control voltage +Vp from the control terminal 11 via the resistor 11 are added to a summing point 9. Further, an electric charge of Q1=(V1n+ Vp)(C7+C21) is stored in the combined capacitance C7+C21 of the output electrode 5 and the control electrode 6 by a positive potential of the summing point 9 and an electric charge of Q2=VpC20 is stored in the capacitor C20 of the input electrode 4 and the control electrode 6. Thus, the lowest potential Vx of the control electrode 6 is expressed as Vx=Vp and the potential of the control electrode 6 always keeps the cut-off voltage Vp of the FET 2, then the input electrode 4 and the output electrode 5 keep the OFF state.
|
