Hi,
The FRAM current consumption will change with frequency of the SPI communication. Yes, the current will scale with frequency. We do not have any tested data at 1KHz currently to provide to you.
With regards to MRI, Cypress has published a whitepaper on F-RAM magnetic field immunity which compares Cypress's F-RAM and nvSRAM product magnetic field immunity against the MRAM memories. These tests are done in our lab where we were able to create magnetic field of up to 3,700 Gauss and proved that Cypress's nonvolatile memories: F-RAM and nvSRAM do not fail while MRAM products start showing failure in a magnetic field strength about 1/20th of 3,700 G. Test was limited to at 3,700 G because this was the setup limitation not the Cypress's nonvolatile products limitation. You can find the attached whitepaper which provides details on "F-RAM, nvSRAM, and MRAM Magnetic Field Immunity".
Whitepaper Link:http://www.cypress.com/file/46731/download
Regards,
Pradipta.
