| 摘要 |
PURPOSE:To reduce the power consumption of a circuit, by using transistors (TRs) in different conduction type for pull-up TRs of an output pull-up circuit and conducting or interrupting the pull-up TRs as required. CONSTITUTION:When a current driving TR6 is interrupted, the collector potential of the TR6 is increased, a current flowing to the resistor 11 drives off- buffer TRs8 and 9 and a control TR21 via a resistor 18. A PNP TR22 is saturated and driven with a base current limited by a resistor 20. When the current drive TR6 is conductive and the collector potential of the TR6 is lowered, since the control TR21 is interrupted by a resistor 19, no base current exists in the TR22, and the TR22 is interrupted. Thus, undesirable current does not flow. |
