| 摘要 |
PURPOSE:To improve switching speed of a circuit by providing buffer circuits between the collector of the level shift transistor (TR) of a TTL and that of a phase- division stage transistor, and a power source. CONSTITUTION:When a voltage VI is applied to one of input terminals 1 and a 1-level input voltage is applied to the other input terminal, a level lshift transistor TRQ1, a phase-division stage TRQ2, and an output TRQ3 turn on and an output at a terminal 3 shows a level 0. As the voltage VI drops, the TRs Q1-Q4 turn off. At this time, if the rise of the collector voltage of the TRQ2 lags that of the TRQ1 and a difference between the both increases, a TRQ7 and a Schottky barrier diode SBDD2 turn on to charge the collector capacity of the TRQ2 forcibly. Consequently, the collector potential of the TRQ2 rises rapidly to shorten the turn-off time of the circuit. |
