| 摘要 |
PURPOSE:To make it possible to perform easily switching operation by a single reference signal and two control signals, by using switching circuits and an inhibit circuit. CONSTITUTION:Differential switching circuits 5, 8 and 11 are composed of a couple of identical-conduction type transistors respectively, and inhibit circuit 14 of a couple of identical-conduction type transistors. Further, a constant bias signal (the 3rd control signal) is applied constantly to control signal terminal 25. When the 1st control signal and 2nd control signals are denoted by X and Y, transistor TRs 7, 9 and 13 all conduct with Y greater than Z while other transistors are unconductive, so that the 1st input signal A will appear at output terminal 24. Under a condition of X>Y>Z, applying both X and Y makes TRs 6, 10 and 13 conductive, so that the 2nd input signal B will be outputted from terminal 24. In case of only Z, inhibit circut 14 only conducts to output Z from terminal 24. In this way, an input signal can be switched depending upon the states of control signals X, Y and Z. |
