| 摘要 |
PURPOSE:To prevent a lowering of a reading speed owing to a deterioration of a reading power source voltage by detecting a bit line level by a feedback circuit to control a discharge of the bit line. CONSTITUTION:A feedback control circuit formed by N-type and P-type transistors N50, P20, N30 detects that a level of a bit line V10 is high, turns off the transistor N50 and raises a level of the nodal point V30. Thereby, the transistor P30 becomes further non-conductive and a level of a nodal point V50 is lowered and a transistor 70 is turned off and a level of a nodal point V60in raised. Then, a transistor N80 is turned on, an improper potential of the line V10 is discharged and rapidly lowered and a delay of a reading speed owing to a deterioration of a reading power source voltage is prevented. |
