| 摘要 |
PURPOSE:To generate reference charge stably by making an initial-stage cell larger than a 2nd-stage cell and by drawing excess charge back from the 2nd-stage cell to the initial-stage cell. CONSTITUTION:When clock (phiM) increases in level, charge is inputted to the reverse surface of electrode 152 from source region 12 through barrier 161 of initial- stage cell 52 and when it decreases in level, a storage region of 2nd-stage cell 51 is filled and since cell 52 is larger than cell 51, cell 52 has part of charge left. Next, when clock (phiM) becomes high in level, the quantity of charge determined by the surface potential of 2nd-stage barrier region 163, the surface level difference of the charge storage region and channel width is left in cell 51 and excess charge is returned to cell 52; and the charge left in cell 51 is divided into two and sent to 3rd-stage cell 53 generating reference charge. Therefore, setting to a value twice as much as the reference charge by cell 52 is done definitely and the reference charge can be generated stably. |
