HIGH DENSITY MEMORY SENSE AMPLIFIER

PROBLEM TO BE SOLVED: To provide a circuit for a high density resistive memory array in which a leak current from a cell being not selected is suppressed to the absolute minimum. SOLUTION: This sense amplifier (38) comprises differential amplifiers (Q5, Q6) provided with first and second input nodes (74, 75), and reads out data in a multiple-state memory cell (RM) of a resistive memory array (30) responding to read-out voltage (VR) applied to both ends of the memory cell (RM) being sensed. Sense circuits (A1, Q1, Q2) decide a current of the memory cell (RM) by applied read-out voltage (VR), and apply a sense current indicating a current of the memory cell (RM) to the first input node (74) of the differential amplifier. Reference circuits (A2, Q3, Q4) are provided with first and second resistive elements (RH, RL) for applying the reference current to the second input node (75) of the differential amplifier to provide a reference value to be compared with the sense current to determine the state of the memory cell (RM). COPYRIGHT: (C)2003,JPO