ALLPCB
Overview
MRAM is a non-volatile magnetic random-access memory. It combines the high-speed read/write performance of SRAM with the high density of DRAM, and it supports effectively unlimited write endurance.
MRAM Features
- Read/write cycle time: 35 ns;
- Effectively unlimited erase/write cycles;
- Industry-leading endurance and data retention - nonvolatile retention exceeding 20 years;
- Maximum single-chip density: 16 Mb;
- Fast, simple interfaces - 16-bit or 8-bit parallel SRAM, 40 MHz serial SPI interface;
- Cost-effective - as simple as a single transistor and a magnetic tunnel junction (1T-1MTJ) per bit cell;
- Excellent soft error rate - significantly better than other memories;
- Can replace multiple memories - combines functions of flash, SRAM, EEPROM, and DRAM;
- Available in commercial, industrial, extended, and automotive temperature ranges;
- RoHS compliant: no battery, lead-free;
- Small packages: TSOP, VGA, DFN.
MRAM Storage Mechanism
MRAM is based on magnetic tunnel junction (MTJ) storage cells. An MTJ contains a fixed layer with a stable magnetization direction and a free layer separated by a tunnel barrier. When the free layer is magnetized in the same direction as the fixed layer, the MTJ exhibits low resistance; when it is opposite, the MTJ exhibits high resistance. This magnetoresistive effect allows fast reads without changing the stored state. Writing occurs when currents through two orthogonal metal lines generate sufficient magnetic field to switch the MTJ's free layer at the intersection, and this write process can be performed at SRAM-like speeds.
Advantages of MRAM
Advantage 1: Information is stored via magnetic polarization rather than charge, avoiding charge leakage and enabling long-term data retention across a wide temperature range.
Advantage 2: Switching between magnetic states does not involve physical movement of electrons or atoms, so there is no wear-out mechanism.
