Memory with one-time programmable (OTP) cells

A method of performing a one-time-programmable (OTP) write to a magnetoresistive random access memory (MRAM) cell to blow the MRAM cell by causing a permanent breakdown of a Magnetic Tunnel Junction (MTJ) of the MRAM cell, the method comprising:

• iteratively applying an OTP write pulse to the MRAM cell until a comparison between a read current of the MRAM cell and an initial OTP program current reference indicate breakdown of the MTJ has occurred;
• after the breakdown has occurred, iteratively increasing the initial OTP program current reference until the read current of the MRAM cell is no longer greater than the increased initial OTP program current reference;
• and
• after the iteratively increasing the initial OTP program current reference, applying at least one additional OTP write pulse.

A magnetoresistive random access memory (MRAM) comprising:

• an MRAM array including MRAM cells arranged in rows and columns, each MRAM cell of the MRAM array including a corresponding Magnetic Tunnel Junction (MTJ) which includes a corresponding tunnel dielectric layer, wherein the corresponding MTJ is capable of being in a blown state or non-blown state, in which the blown state corresponds to a permanent breakdown of the corresponding tunnel dielectric layer;
• write circuitry configured to perform a one-time-programmable (OTP) write operation to blow selected MRAM cells of the MRAM array, wherein, for each MRAM cell being blown, the write circuitry is configured to:
• iteratively apply an OTP write pulse to the MRAM cell until a read current of the MRAM cell being blown is no longer less than an initial OTP program current reference, indicating occurrence of tunnel dielectric breakdown,
• after the occurrence of tunnel dielectric breakdown is indicated, iteratively increase the initial OTP program current reference until the read current of the MRAM cell is no longer greater than the increased initial OTP program current reference, and
• after the iteratively increasing the initial OTP program current reference, applying at least one additional OTP write pulse.