A sense-amplifier circuit can be used with a non-volatile memory device having a memory array with memory cells arranged in word lines and bit lines and coupled to respective source lines. The circuit has a first circuit branch and a second circuit branch, which receive on a respective first comparison input and second comparison input, during a reading step of a datum stored in a memory cell, a cell current from the bit line associated to the memory cell and a reference current, from a reference bit line in a differential reading operation or from a current-reference generator in a single-ended reading operation. The first and second circuit branches generate, during the datum-reading step, a first output voltage and a second output voltage, as a function of the difference between the cell current and the reference current.