| 摘要 |
PURPOSE:To heighten the power supply margin of the discharge current origin and to obtain nonreverse current circuits of holding currents by connecting the respective negative word lines through the section between the collector and emitter of the transistor to the discharge current origin and connecting the base of the said transistor through the resistance to positive word lines which are paired with the negative word lines. CONSTITUTION:When WL1 is assumed to be a selective word line, the W<+> line electric potential is decreased at the time of transfer to nonselection, and accordingly, the base current IB and collector current IC of an npn type Tr T1 are also reduced, and therefore, the current is led-in in correspondence to word line electric potential and the word line electric potential is decreased. When WL1 is assumed to be a nonselective word line, the Tr T1 is saturated and prevents reverse current. Since the voltage drop of resistance R1 can be disregarded, the electric potential difference between W<+> and current origin IDIS becomes a voltage VBE between the base and emitter of the Tr T1, and a W<-> electric potential becomes W<+>-VBE. Consequently, the W<-> electric potential is equal to the current origin IDIS. Under this condition, the Tr T1 operates at the saturated region, a current value IB for the current IC becomes larger and reverse currents from other nonselective word lines are suppressed. Moreover, since the Tr T1 emitter electric potential is W<->, the power supply margin is not decreased. |
