| 摘要 |
<p>PURPOSE:To erase a data adequately and in a short period of time by detecting node voltage raised by a terminal voltage and interrupting voltage application to a source when the node voltage is increased to a prescribed value or above. CONSTITUTION:When a data stored to a memory cell MC is erased, voltage is applied to a source terminal (e) and a control gate is held to ground potential. At this time, a transistor T15 is turned on, T14 is turned off, a node N1 is separated electrically from a load transistor T12 and connected with a node (a). Thus, the potential of the node (a) is raised by the voltage of the terminal (e), the voltage appearing to the drain side of the memory cell is detected by a voltage detector 21. At this time, electron is injected to a floating gate by a data writing means, the data is written, when the source voltage is applied, the data is erased. Then, when the voltage detected by the circuit 21 is increased to the prescribed value or above, no electron is injected and erasing is stopped. Thus, the repeat of the erase and confirmation is eliminated and the data is erased in a short period of time.</p> |
