Low-Power Write-Circuit with Status-Detection for STT-MRAM

We report a STT-MRAM write-scheme, in which the length of the write-pulse is determined dynamically by sensing the status of MTJ cells. The proposed scheme can reduce the power consumption by eliminating unnecessary writing current after the switching has occurred. We also propose a reference cell design, which is optimized for the use in writecircuits. The performance of the proposed circuit was verified by SPICE level simulations of the circuit implemented in a 0.13 μm CMOS process.