Patent ID: 7224630
Filing Date: 2007-05-29
Classification: G11C

Abstract:
1. An antifuse circuit comprising: a sensing circuit having a first input, a second input and an output, the output of the sense amplifier providing a logic value that indicates whether the antifuse circuit has a first resistance state or a second resistance state, wherein the first resistance state is characterized by being a higher resistance than the second resistance state; an antiflise magnetic tunnel junction coupled to the first input of the sensing circuit, the antiflise magnetic tunnel junction initially having the first resistance state which can be permanently changed to the second resistance state in response to receiving a predetermined program voltage; a resistive unit providing a third resistance between the first and second resistance consisting of a plurality of reference magnetic tunnel junctions in the first resistance state coupled in parallel, the resistive unit being coupled to the second input of the sensing circuit; and a write circuit coupled to the antifuse magnetic tunnel junction, the write circuit selectively providing a current sufficient to create the predetermined program voltage when the write circuit is enabled to program the antifuse magnetic tunnel junction.