| 摘要 |
PURPOSE:To remove a noise to occur in a self-exciting oscillator and to obtain a digital signal having no influence of the noise by detecting the in-phase noise of the oscillation output of an inversion amplifier circuit to output first and second oscillation output signals respectively having reverse phases and holding the oscillation output during a noise occurrence period. CONSTITUTION:When the noise occurs in waveforms 21 and 22 of the oscillation outputs from terminals C' and C of an inversion amplifier circuit 1, and the waveforms 21 and 22 temporarily become in-phase, the outputs of EXNORs 2 and 3 temporarily become a high level respectively, and the output of a NOR 6 temporarily becomes a low level (in-phase). At this time, since a delay circuit 4 slightly hourly shifts the outputs of the EXNORs 2 and 3, a low-level waveform 23 obtained by expanding the pulse width of the in-phase pulse is given from the NOR 6 as the control input of a transfer gate 7, the gate 7 is made into an interrupted state, and a transfer gate 8 is made into a conducting state. In this case, for the output of an inverter 12, a level immediately before the in-phase noise occurs held by inverters 10 and 11 is held as it is, and the oscillation output including the noise from the terminal C never appears. |
