| 摘要 |
PURPOSE:To always stabilize the reference voltage of a sense amplifier by adjusting the reference voltage by means of a capacitor connected between a bit line and a dummy word line,and allowing the voltage amplitude of the dummy word line to depend upon the reference voltage. CONSTITUTION:When the reference voltage VR itself is impressed to the dummy word line, the amplitude of the dummy word line depends upon not power supply voltage but the reference voltage VR. When the initial value of the reference voltage is V0, the amplitude VW of the dummy word line is set up to VW=V0. Since the reference voltage is generated by shorting a pair of bit lines, the error of the voltage VR to be varied with the passage of time can be reduced. A reference voltage VRt at the time of sense amplifying operation when the voltage V0 is varied to DELTAVt by leak current, is expressed by the shown equation. Provided that CB is the parasitic capacity of the bit line and CR is correcting dummy capacity. Consequently, the reference voltage can be always stabilized. |
