| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device by which the variation in a threshold voltage of a main body memory cell caused by variation in a threshold voltage of a reference memory cell is suppressed. <P>SOLUTION: The device is equipped with: a memory cell MC; a reference memory cell RMC; a sense amplifier SA10; a load circuit of current mirror type connected to the sense amplifier; a first transistor N23, one end of which is connected to a second input end of the sense amplifier; a reference current source 25 connected to another end of the first transistor; and a second transistor N21, one end of which is connected to the second input end of the sense amplifier, and to another end of which the selected memory cell MC is connected. When the threshold voltage of the reference memory cell is adjusted, the first transistor is turned ON and the second transistor is turned OFF, and when the threshold voltage of the memory cell at the verify of write/erasure with respect to the memory cell is adjusted, the first transistor is turned OFF and the second transistor is turned ON. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
