| 摘要 |
PURPOSE:To obtain a current switch circuit which is suitable for the monolithic integrated circuit and also is high in the output impedance in case of a closed state, by connecting the output of the NOR gate to which the source of FET and the control signal are applied, to the gate of FET. CONSTITUTION:When the input to the terminal 46 is in a low level, the NOR gate 30 is operated as an inverter circuit which makes the terminal 32 its input and makes the terminal 31 its output, that is to say, an inverse amplifier. Accordingly, the FET21 and the NOR gate 30 constitute a feedback loop, the FET30 is fed back, biased and made to conduct, and a current is output from the terminal 47. On the other hand, when the input to the terminal 46 is in a high level, the output of the NOR gate 30 becomes a low level, the feedback path is selectically cut off, the FET21 becomes a cut-off state, and therefore the terminal 47 becomes an off state. |
