| 摘要 |
A regular capacitor is saturated by the electric charge of a regular cell memory holding a high logic level. The regular capacitor is not saturated by an electric charge from a regular memory cell holding a low logic level. A reference capacitor is saturated by an electric charge from a reference memory cell holding the high logic level. A differential sense amplifier amplifies the difference between a regular read-out voltage read out from the regular capacitor and a voltage lower by a first voltage than the reference read-out voltage which is a saturated voltage read out from a reference capacitor, and generates the logic of the data held in thememory cell. Variations in a reference voltage and a read-out voltage corresponding to the high logic level can be reduced even in the case where the characteristic of the capacitor of the memory cell varies. Thus, the difference between the reference voltage and a read-out voltage corresponding to the low logic level can be relatively increased. As a result, the read-out margin can be improved.
|
