| 摘要 |
PURPOSE:To detect stably the transition of signal logical level with comparatively simple constitution by using an inverting circuit and a flip-flop circuit to detect that an output signal is at the same logical level. CONSTITUTION:When the logical level of an input signal A is transited from a high level to a low level, an output signal B1 of an NAND gate 31 rises from a low to a high level with a few delay. This output signal B1 is inputted to an NAND gate 21 together with an inverted input signal -A to change an output signal B2 of the NAND gate 21 from a high to a low level. Since the change in the signal B2 is delayed slightly more than the change in the signal B1, a section of simultaneous high level is produced and a pulsive detecting signal C is outputted. When the logical level of the input signal A is transited from a low to a high level conversely, the output signal B1 is changed from a high level to a low level with a few delay by the rising of the signal B2 and a pulsive detecting signal is outputted. |
