| 摘要 |
PURPOSE:To obtain an input circuit of high noise resistance by connecting a signal delay circuit using a capacity to the output of a CMOS inverter which takes an external input signal as the gate input and connecting a Schmitt trigger circuit to the output of this delay circuit. CONSTITUTION:The signal given to an input terminal 1 is received by a CMOS inverter 3 and a capacity 4 is connected in parallel with the output of the inverter 3. When on-state resistances of P-type MOS transistor TR and an N-type MOS TR constituting the inverter 3 are denoted as RPON and RNON respectively and the capacity value of the capacity 4 is denoted as C, a rise (fall) waveform of 2CRPON(2CRNON) is outputted from the CMOS inverter 3. CMOS inverters 5-7 constitute a Schmitt trigger circuit. Thus, the input circuit of high noise resistance of an input signal is obtained. |
