| 摘要 |
PURPOSE:To prevent the generation of distortion, by setting the level of a control signal in the state, where an FET is turned on, so that this level does not exceed the forward voltage even for a high-level input signal in an analog switch using the junction FET. CONSTITUTION:In case the high-level input signal is given to a terminal P1, a current is flowed from a gate G to a drain D to generate a distortion in the output signal if the potential of the input-side drain D exceeds the forward voltage for the potential of the gate G near the negative-side peak. In this case, when a resistance R4 is inserted between the emitter of a transistor TRQ and a reference voltage, the potential of the input-side drain D does not reach the forward voltage of the FET even when the difference between the potential of the gate G of the FET and that of the input-side drain D is maximum. Consequently, no current is flowed from the gate G to the drain D, and the distortion is not generated in the output signal. |
