| 摘要 |
PURPOSE:To prevent an input analog voltage from being lowered, by making a gate control signal to an analog switch and a switching circuit different from each other, in the analog switch charging/discharging a gate capacitance with a constant current. CONSTITUTION:The generation of switching noise is prevented by charging/discharging the gate capacitance of transmission gates 14, 15 at turning on and off. Switching circuits 31-34 and 20 switching constant current FETs21, 22, 26, 27 with a control signal Vc are provided to the switch circuit constituted in this way. Another control signal Vc changed steeply different from the signal controlling the gate 11 and its inverting signal are applied to FETs 16, 17 and 19 constituting the switching circuit 20. Thus, an input terminal 12 is not connected to a power supply Vss through the constitution in this way and the reduction of an input voltage Vi at switching is prevented. |
