Variable sense level for fuse-based non-volatile memory

A circuit comprising:

• a fuse circuit;
• a comparator circuit configured to compare a first signal indicative of a resistance of the fuse circuit to a second signal indicative of a reference level, at least one of the first and second signals being digitally controllable, the comparator circuit being configured to generate a digital output signal indicative of the comparison;
• and
• a first digital-to-analog converter circuit configured to generate a first analog signal based on at least a first plurality of digital signals, the first signal being at least partially based on the first analog signal;
• wherein the fuse circuit comprises a plurality of individual fuse circuits selectively coupled to the comparator circuit.

A circuit comprising:

• a fuse circuit;
• a comparator circuit configured to compare a first signal indicative of a resistance of the fuse circuit to a second signal indicative of a reference level, at least one of the first and second signals being digitally controllable, the comparator circuit being configured to generate a digital output signal indicative of the comparison;
• and
• a monitor circuit comprising at least one switch circuit for selectively coupling a terminal of an integrated circuit including the circuit to a selected one of a first input terminal of the comparator and a second input terminal of the comparator.

An apparatus comprising:

• a fuse circuit on an integrated circuit;
• a comparator circuit configured to generate a digital output signal indicative of a difference between a first signal indicative of a fuse resistance and a second signal indicative of a reference level;
• and
• means for digitally controlling at least one of the first signal and the second signal to characterize the fuse circuit, the means for digitally controlling being on the integrated circuit,
• wherein the means for digitally controlling is responsive to the digital output signal.