| 摘要 |
PURPOSE:To prevent the excessive current due to punch-through, by limiting the write-in current with the current control transistor provided in series with the memory transistor. CONSTITUTION:The memory section 11, write-in current control transistor Tc circuit 12, and gate control signal generation circuit 13 of Tc are provided. The Pro signal at write-in is at high level in the circuit 13, the Tc gate output voltage is suppressed lower, Tc current is limited, Pro signal is made to a low level at readout, Vf is a high voltage, and the conduction resistance of Tc is very small. Further, at write-in, in the memory transistor current, the current required for write-in is made near the saturation current of Tc (several mA). Thus, excessive current due to punch-through can be prevented. |
