| 摘要 |
PURPOSE:To obtain a semiconductor circuit suitable for high circuit integration by providing a control means controlling the 2nd transistor (TR) gate in response to the potential at a connecting point between the 1st and 2nd TRs so as to constitute a Schmitt trigger circuit with less number of components. CONSTITUTION:When an input signal rises from 0 to 5V, a TR Q11 changes from ON to OFF and a TR Q13 changes from OFF to ON state. The conductive resistance of a TR Q12 is comparatively high at the leading of the input signal and the potential at a connecting point N1 is hardly decreased. Thus, a circuit threshold value at the leading of the input signal does not depend only on each threshold voltage of the TRs Q11, Q13 and a higher voltage is required to bring the TR Q13 to a deeper ON state. The potential fed to the gate of the TR Q12 is increased gradually as the potential rise in the input signal. Thus, the conductive resistance of the TR Q12 is decreased and the input signal reaches the potential nearly 5V, then the potential at the connecting points N2, N1 is both 0V and the output of the inverter circuit circuit 11 reaches 5V.
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