| 摘要 |
PURPOSE:To obtain an input circuit for a semiconductor IC capable of surely removing a noise component from an input signal by connecting p-channel and n-channel type MOS transistors(TRs) to a Schmitt trigger type input buffer in a prescribed format. CONSTITUTION:In the constitution consisting of the Schmitt trigger type buffer 4 and n-type and p-type MOS transistors(TRs) 2, 3, an input signal form the input terminal 1 is inputted to an integrated circuit 6 at first. A high frequency noise component superposed to the input signal is attenuated in accordance with a transmission characteristic determined by the turned-on resistance of the TRs 2, 3 and the diffusion capacitance of source and drain electrodes. The input signal of which high frequency component is suppressed is inputted to the buffer 4 and the noise component is completely removed by the buffer 4. Thus the buffer 4 drives an internal circuit 5 in addition to the removal of the noise component. |
