Abstract:
A non volatile memory of the type comprising a predetermined number of sectors capable of ensuring the operation of the same even with a lower number of defective sectors than a predetermined limit.
Abstract:
The invention relates to a method and a circuit for regulating the source terminal (S) voltage to the of a non-volatile memory cell (3) during the cell programming and/or reading phases. The method comprises a phase of locally regulating said voltage value and consists of comparing the source current (Is) of the cell array (3) with a reference current (Iref). A fraction of the source current (Is) is converted to a voltage and compared with a voltage generated from a memory cell acting as a reference and being programmed to the distribution with the highest current levels; the comparison result being used for controlling a current generator (25) to inject, into the source terminal (S), the current necessary to keep the predetermined voltage thereof at a constant value.
Abstract:
The invention relates to an analog-to-digital conversion method and relevant device, in high-density multilevel non-volatile memory devices. The method applies to multilevel memory cells comprising a floating gate transistor with drain and source terminals; the cell to be read is subjected to a reading operation by applying predetermined bias voltage values to its drain and source terminals, while to its drain terminal is applied a predetermined current value (Iref), and by measuring the value of its gate voltage (Vg). The method of the invention comprises a first conversion phase the most significant bits (MSB) contained in the memory cell, followed by a second conversion phase of the least significant bits (LSB). The first step is completed within a time gap (T1-T0) which corresponds to the rise transient of the gate voltage signal (Vg), while the second step is started at the end of the transient.