Active compensation for operating point drift in MRAM write operation

A method for minimizing errors when writing information to memory cells in a magnetic memory cell array with operating write currents,

• wherein the magnetic memory cell array comprises reference cells having known operating characteristics and a magnetization with an alterable orientation, and wherein each reference cell in the magnetic memory cell array has a different junction size, the method comprising:
• applying test write currents having pre-selected attributes for altering orientation of the magnetization of the reference cells, wherein applying the test write currents comprises:
• sinusoidally varying the test write currents:
• measuring a phase difference between the test write currents and switching of the orientations of the magnetizations in each reference cell;
• and
• modifying operating write currents based upon the measured phase difference;
• determining whether the orientations of the magnetizations in the reference cells were altered;
• and
• modifying the operating write currents.