| 摘要 |
PURPOSE:To prevent malfunction due to noise by providing a level detector detecting an input level to the input and a switch circuit to the output of a clock extracting circuit to the output. CONSTITUTION:When an input signal is normal, a switch circuit 11 is in ON- state and a clock is transmitted to flip-flops 8, 9 via the switch circuit 11. When the input is interrupted, a level detector 10 detects it, the switch circuit 11 is turned off so as to block the transmission of the clock. Even when noise is transmitted to a flip-flop with the data output of flip-flops 6, 7, the flip-flop is not operated so as to prevent malfunction due to noise. |
