| 摘要 |
<p>PURPOSE:To attain a fast operation in a device, by using a transistor having a low threshold level as the transistor of a column transfer gate, and providing a circuit that clamps the driving level of a write circuit. CONSTITUTION:At the driving time of a write circuit 2, a clamping circuit consisting of required stages of transistors is provided at the sources of driving transistors T3 and T4, and the level of the circuit is set at the level required for a write. In this way, the excessive lowering of the levels of a bit line BL, and the inverse of BL can be prevented, and a fast write can be obtained without making worse a write recovery time. Also, at a readout time, by the column transfer gate consisting of write/non-dose transistors T1 and T2 having the low threshold levels and high mutual conductances, the information of the bit line is transmitted to data buses DB and the inverse of DB, thereby a fast readout can be obtained.</p> |
