Accurate calculation and shaping of the voltage pulse waveform applied to a voltage-controlled magnetic random access memory cell

This paper presents procedures for calculating and shaping the voltage pulse waveform applied to a voltage-controlled magnetic random access memory (VC-MRAM) cell, which are indispensable experimental steps for studying the dynamic toggle switching of the VC-MRAM cell driven by the application of a high-speed voltage pulse. The calculation of the voltage waveform starts from the detailed characterization of each part of the pulse propagation path using a vector network analyzer. The obtained S-parameters are used to calculate the frequency response of the entire path. Next, the output waveform of the signal source is captured using a high-speed sampling oscilloscope, which is Fourier transformed, multiplied with the frequency response of the pulse propagation path, and inverse Fourier transformed to calculate the time domain voltage waveform applied to the device under test. We also present a procedure to shape the voltage waveform as desired by taking the reverse calculation process. The calculated and observed waveforms showed close agreement in both the waveform calculation and shaping. (C) 2018 The Japan Society of Applied Physics