| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a voltage generator which outputs a voltage having good characteristics even if a supply voltage or the like changes. <P>SOLUTION: A substrate bias voltage Vbb is applied to a back gate of an N transistor 35. A drain-to-source resistance of the N transistor 35 rises when the substrate bias voltage Vbb lowers due to pump operation of a charge pump circuit 20 (substrate bias effect). When a first supply voltage Vcc is set high, a drain-to-source current of the N transistor 35 increases (I+▵I1). However, the drain-to-source current reduces by just that much (I+▵I1-▵I2) due to the substrate bias effect, and potential rise of a node N34 caused by rising of the first supply voltage Vcc is also restrained. As a result, the reference level of the substrate bias voltage Vbb does not largely lower from the reference level of the substrate voltage Vbb when the first supply voltage Vcc is at a standard level. <P>COPYRIGHT: (C)2004,JPO |
