| 摘要 |
PURPOSE:To attain a stable writing operation by inserting a resistance between an emitter of a final step transistor of a word driver circuit selecting a word line and an electrode of the lowest potential. CONSTITUTION:A resistance Rw is inserted between word drivers WD1, WD2 and an electrode of the lowest potential. A Tr Q5 absorbs a current 67mA passing through a word line W2 and when adding its base current, an emitter current of the Tr Q5 becomes 70mA. When determining Rw so as to satisfy 2V+70mAXRwOMEGA=3.3V, an emitter potential of Q1 is raised to 2V+70 mAXRwOMEGA, which can be same as the base potential of Q1. Rw becomes 18.5OMEGA and by inserting 18.5OMEGA between the emitter of a final step transistor of a word driver and an electrode of the lowest potential, Q1 is prevented from being turned on. Thereby, the effect of a parasitic transistor is restricted and a stable writing operation can be performed. |
