| 摘要 |
<p>PROBLEM TO BE SOLVED: To eliminate the need for a transistor with an especially high thresh old, to reduce an occupation area, speed up an operation, and also to reduce the number of manufacturing processes by applying a back-gate voltage to the transistor for a charge switch for increasing a threshold voltage. SOLUTION: A charge circuit 12 connects a back gate to a terminal 104 for supplying a back-gate bias voltage VPB, connects a source terminal to a terminal 105 for supplying a charge voltage VPM, connects a gate terminal to the output of a NOT logic gate 107, and is constituted by a P-type MOS transistor 110 with a drain terminal as output. The threshold voltage of the P-type MOS transistor 110 is changed by a back-gate bias voltage VPB being applied to the back gate and a charge voltage VPM being applied to the source terminal due to a back-gate effect. In this case, the change in the threshold can be modified appropriately by the back-gate voltage to be applied.</p> |
