NONVOLATILE FERROELECTRIC MEMORY DEVICE HAVING MULTI BIT CONTROL FUNCTION, ESPECIALLY SELECTING A PLURALITY OF CELL AND READING/WRITING MULTI BITS FROM/IN MEMORY CELLS

摘要

PURPOSE: A nonvolatile ferroelectric memory device having a multi bit control function is provided to obtain stable data sensing value with low distribution using average characteristics of a plurality of cells selected simultaneously and to improve operation speed of the nonvolatile ferroelectric memory. CONSTITUTION: The nonvolatile ferroelectric memory device has a 2T2C(2-Transistor,2-Capacitor) structure by comprising two transistors(T3,T4) and two ferroelectric capacitors(FC3,FC4). The transistor(T3) is connected between a bit line(BL1) and the first electrode of the ferroelectric capacitor(FC3) and its gate is connected to a word line(WL). The second electrode of the ferroelectric capacitor(FC3) is connected to a plate line(PL). The transistor(T4) is connected between a bit line(BL2) and the first electrode of the ferroelectric capacitor(FC4) and its gate is connected to the word line. The second electrode of the ferroelectric capacitor(FC4) is connected to the plate line. The bit line(BL1) is connected to a column selection switch(CS1), and the bit line(BL2) is connected to a column selection switch(CS2). A sense AMP compares the voltage level of averaged data supplied from the common data bus with reference voltage, and it amplifies it.