| 摘要 |
PURPOSE:To secure the level detection of a high sensitivity by changing the reference voltage automatically in accordance with the potential of the input signal, reducing the coupling conditions of the level detection circuit to the input signal system circuit and then lessening the unbalance of the load. CONSTITUTION:Input terminal 12 is connected to level detector circuit part 19 via gate MOSFETT6 of gate circuit part 18. Then the reference potential is generated through part 19 to detect the potential change of the input signal. The FF comprising MOSFETT7 and T8 is provided at part 19, and the sources of FETT7 and T8 are connected in common and then earthed via MOSFETT3 along with their gates connected to each other. The gate is furthermore connected to MOSFETT9 which generates the reference potential, and the drain of T9 is connected to power source VD. At the same time, joints 21 and 22 between TrFETT7/T8 and T9 each are connected to MOSFETT10 and T11 of output circuit part 23. Then the high potential level delivered from TTL logic element 24 which delivers the high potential level during the holding period is detected through part 19, thus carrying out the level detection of a high sensitivity. |
