| 摘要 |
<p>PURPOSE:To make it possible to shorten the writing time, by providing a capacitor for holding a writing voltage between a control gate and a source in a memory cell. CONSTITUTION:A capacitor C for holding writing voltage, which has the capacity of about 0.1pF is connected between a control gate terminal of an MOS transistor 18 and a source terminal S thereof. When data is written, a writing voltage of 15V is applied from a high voltage source, whose output impedance is, e.g., 10kOMEGA, to the terminal CG. Then, the capacitor C is charged to 15V in several ns. The ON state of the MOS transistor 18 is maintained by the voltage of the capacitor C. At this time, when, e.g., 10V is applied to a drain terminal D, hot carriers are generated, and writing is performed in 100mus-1ms. Therefore, the operating time of the high voltage source of 15V is only several ns for one memory cell. Thus, the data writing time can be shortened.</p> |
