The University of Oxford claims to have a more compact read cell for MRAM. “It is an offset read protocol and uses a single transistor per line,” said inventor Dr Chris Padbury.
According to Padbury, conventional MRAM read circuits use a form of virtual-earth read protocol. “This uses an op-amp which is slow, and takes up a lot of room,” said Padbury.
Offset bias read involves using a selected MRAM cell, which has one of two resistances depending on the state stored, in the base circuit of a bipolar transistor.