| 摘要 |
PURPOSE:To obtain an input circuit of a semiconductor integrated circuit which can be used in the circumstances of a strong noise, by adding a capacitor between an input terminal and a power source potential to reduce the influence of capacitor coupling upon the external. CONSTITUTION:An input terminal 16, a pull-down resistance 17, an inverter 18 functioning as a buffer, and a capacitor 19 are provided as shown in Fig. The resistance 17 and the capacitor 19 are connected in parallel, and one of them is connected to -Vss, and the other is connected to the input terminal 16. The input terminal 16 is the input of the buffer 18, and the capacitor 19 whose electrostatic capacity is >=2PF is added to a conventional circuit. The capacitor whose electrostatic capacity is considerably larger than the parasitic electrostatic capacity of the conventional input circuit is added between the input terminal and the power source potential to prevent the noise due to capacitor coupling. |
