| 摘要 |
PURPOSE:To enable to use only one bootstrap which has the same input voltage range as the power supply voltage range and occupies the area, by constituting the multiplexer through the combination of IGFET of depletion type and enhancement type. CONSTITUTION:The resistive elements R1-Rn are connected in series between the reference voltage terminal 1 and the semiconductor substrate potential end 9, and the drain of the depletion type IGFETD1-Dm is connected at the nodes 10-12. The potential at the node 12 of the resistive elements Rm and Rm+1 is greater than the absolute value of D type IGFET and it is the potential nonconductive when the gate of D type IGFET is at ground potential. The drain of the enhancement type IGFET is connected to the nodes 13 and 14. The analog switch can be made to nonconductive or conductive by taking the potential of the control signals A-H at the substrate potential or more. Sufficiently greater voltage is produced for the control signal G at the bootstrap circuit and applied. |
