Apparatus and system for reading non-volatile memory with dual reference cells

A method for reading data in a memory cell, the method comprising the operations of:

• comparing a first reference cell voltage and a memory cell voltage from a memory cell to produce a first output signal;
• comparing a second reference cell voltage and the memory cell voltage to produce a second output signal, the second reference cell voltage being different from the first reference cell voltage;
• and
• comparing the first output signal and the second output signal to produce a third output signal.

An apparatus for reading data contained in a memory cell, comprising:

• a first reference cell having a high threshold voltage for providing a low reference current;
• a second reference cell having a low threshold voltage for providing a high reference current;
• a first load for receiving the high reference current and outputting a first reference voltage;
• a second load for receiving the low reference current and outputting a second reference voltage;
• a first comparator for receiving the first reference voltage and a memory cell voltage and generating an output signal;
• a second comparator for receiving the second reference voltage and the memory cell voltage and generating an output signal;
• and
• a third comparator for receiving the output signals from the first and second comparators and generating an output signal.