| 摘要 |
PURPOSE:To introduce easily a leading/trailing threshold voltage of an input waveform depending on the ratio of conductivities based on P and N-channel MOS transistors (Trs) by arranging the said Trs between input and output terminals. CONSTITUTION:P-channel MOS Tr3 and N-channel MOS Trs 4, 5, 6 and an inverter are connected between the input and output terminals 1 and 2. Suppose that the on-resistance of the Tr5 is negligibly small than the on-resistance of the Tr6 and the propagation delay time of the inverter 7 is sufficiently slower than the change in the input waveform. The entire threshold voltage VTI of the circuit is expressed as equation 1, where VTN, VTP are threshold voltages of the N-channel Trs and the P-channel Tr respectively, betaR is the ratio of the conductivity of the Trs 4, 5, 6 to the Tr3 and VDD is a voltage of a power supply 8. When the input waveform is leading waveform, since the Tr5 is turned off, the betaR is calculated as the ratio of the Tr3 to the Tr4. When the input waveform is a trailing waveform, the Tr5 is turned on and since the on- resistance is negligibly small than the ON-resistance of the Tr6, the betaR is calcu lated from the ratio of the Tr3 to the Trs 4, 6 connected in parallel.
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