| 摘要 |
PURPOSE:To control hysteresis characteristics with good accuracy and to reduce number of components, by constituting 4 C-MOS transistors(TRs) at least a Schmitt trigger circuit. CONSTITUTION:When a signal input voltage VIN is at L level, NMOSTRs 3 and 4 are nonconductive and PMOSTRs 1 and 2 are conductive, and an output terminal 4 is at H level. When the voltage VIN gradually increases, the on-resistance of the NMOSTR4 is gradually decreased and a voltage VN divided with NMOSTRs 4 and 6 are gradually lowered. When the VIN exceeds VN+Vt3, the NMOSTR3 turns on and an output signal voltage Vout is rapidlly decreased into L level with positive feedback. When the signal input voltage goes from H to L level, the similar operation is made by the PMOSTRs 1, 2, and a TR5. |
