| 摘要 |
PURPOSE:To prevent a write current from branching to a nonselective memory cell, by making a variation characteristic of nonselective word line potential follow a variation characteristics of selective word line potential. CONSTITUTION:A circuit C1 is a biasing circuit and generates prescribed bias voltage VB. A circuit C3 is a circuit for varying the voltage VRX in accordance with a sink current (i) of a dummy cell circuit C2. When the sink current (i) is reduced, a lot of discharge currents flow to a selective work line, and amplitude of the word line is reduced, potential of a node N1 rises, therefore, a transistor T45 is controlled toward the on-direction. As a result, the potential VRX rises, and a constant-current value IC of all word decoders WD0,... increases. As a result, the base potential of a nonselective driver drops. In this way, by controlling the constant-current source by the circuits C1-C3, the minimum of the word line potential amplitude is secured. |
