| 摘要 |
PURPOSE:To increase a switching speed by making it easy to detect a signal level, by previously matching the reference potential of a differential amplifier with the logical polarity of the next signal. CONSTITUTION:When input signal 20 is held at a high level of 5V, a voltage of 4V, less by the threshold level of about 1V of transistor 18, is output to node 24 via delaying circuit 30; and after signal 20 switches from the high level of 5V to the low level of 1V, node 20 when exceeding a potential 4V at reference node 24 of a differential amplifier outputs voltages of about 4V and 1V to output contacts 21 and 22 of the differential amplifier, and node 24, receiving those outputs, generates an output of about 2V after certain time delay. Once signal 20 changes from 1V to 5V, outputs of about 1V and 4V are sent to nodes 21 and 22 when the potential at node 24 is about 2V and that at node 20 exceeds 2V and node 24, receivng those outputs, generates about 4V after certain time delay, thereby repeating the above- mentioned operation after this. Consequently, the switching spped can be increased. |
