Moore’s Law was one of the most prescient predictions of the twentieth century. That law predicted that memory capacity would double roughly every 24 months, while the cost of micro-processing power would be halved. The observation was made in 1965, and it has amazingly remained true for the past 55 years. In fact, the curve has accelerated in recent years, actually getting ahead of Moore’s predictions. And technologies like MRAN promise to keep Moore’s Law in effect for years to come.
An Overview of DRAM
DRAM uses random access memory that stores data bits in memory cells. These are usually based on metal-oxide-semiconductor or MOS technology. The materials used in MOS are both transistors and capacitors, so their charged state representing 0 or 1 can be changed. In fact, they slowly lose their charge, so a DRAM system needs to have its data refreshed regularly. This is in contrast to SRAM or static random access memory systems. (The oldest silicon memory chips were SRAM.) DRAM devices are slower but cheaper than SRAM. It tends to be used in the main memory for many computers and portable devices. However, the demand for memory and processing power continues to grow, and the issues with DRAM cause problems in their own right. That’s why there has been research into alternative technologies like MRAN.
What Is MRAN?
What is MRAN, and how will it play a role in future electronics? MRAN will probably be the next generation after DRAM or dynamic random-access memory.
This technology is based on magnetic tunnel junctions. They use magnetism instead of electrical charge to control the charge that can represent the zeros and ones that encode information. The magnetic tunnel junction or MTJ uses ferromagnetic materials that are magnetized in a single direction and a second layer that can be altered from a neutral state to a charged one. The breakthrough, though, is in the size of these transistors. Tohoku University has been experimenting with MTJ technology. And they’ve been able to create MTJ transistors that are on an atomic scale.
What Are the Benefits of MRAM Technology?
The stable magnetic state of the MTJ design means it can hold data for years. This is in sharp contrast to DRAM drives that can lose most of their data within minutes of losing power. MTJ systems can also be updated within ten nanoseconds. This is far faster than SRAM devices. Magnetic tunnel junction technology could be written and rewritten millions of times a seconds. This makes them one of the few options for the supercomputers we want to create. If MTJ technology is rolled out, it will have the side benefit of dramatically reducing power consumption, because the device doesn’t have to continually trickle power through the memory card to retain the data stored there. Smaller devices will reduce losses in general, because current doesn’t have to travel as far when a certain bit needs to be flipped.
More importantly, these microprocessors and memory devices would be much smaller than existing microchips. This allows you to create much smaller and more powerful transistors. This means that MRAN devices could keep Moore’s Law going for another decade.