| 摘要 |
PURPOSE:To obtain a Schmitt circuit whose threshold level can easily be set and which is tolerant of noises, by combining together enhancement (E) type p-channel MOSFET and E type n-channel MOSFET. CONSTITUTION:Between E type p MOSFETQ31 with a threshold level of VTP (negative) and E type n MOSFETQ32 with a threshold level of VTN (positive), both sources are connected to the output terminal and both gates are also connected for the input terminal while the drains of FETs Q32 and Q31 are connected to positive power supply VDD and earth potential VSS respectively. As for the Schmitt circuit of the above-mentioned constitution, the input-output characteristics have hysteresis and the threshold voltage depends upon only the threshold levels of FETs Q31 and Q32 and can therefore be set easily. Further, the output voltage is fixed between VDD-VTN and ¦VTP¦, so that a signal even with a large noise can be transmitted accurately. |
