| 摘要 |
PURPOSE:To speed up the switching by connecting a collector of a transistor (TR) driving an output TR and a power terminal in a logic circuit comprising a DTL and a TTL so as to increase the base current at turn-on only. CONSTITUTION:A capacitor C is connected between the collector of a TRQ2 and common and charged nearly toa power supply voltage when the TRQ2 is turned off. When the level of inputs 1, 2 goes to H and the TRQ2 is turned off, the electric charge in the capacitor is discharged via the TRQ2, the discharge current, a current flowing to a resistor R2' and a base current IB2' of the TRQ2 are superimposed together, resulting being a base current IB3' of a TRQ3 thereby speeding up the turn-on of the TRQ3. Since the capacitor discharge current is lost at on-state of steady-state, the TRQ3 is not over-saturated and the turn-off is quickened. |
