MRAM, the new breed of semiconductor memory uses magnetic properties to store data. This new kind of chip will compete with other established forms of semiconductor memories such as Flash memory and random access memory (RAM). Most engineers believe, that the technology called magnetoresistive random-access memory(MRAM) could reduce the cost and power consumption of electronics for cell phones, music players, laptops and servers. The feature, that makes MRAM an alluring alternative to other forms of semiconductor memories, is the way it stores data. For example, flash memory and random-access memory(RAM) hold information as electric charge. In contrast, MRAM uses the magnetic orientation of electrons to represent bits.Using MRAM, reading and writing of data can be done unlimitedly with in nanaoseconds. MRAM can also hold the data with out a power supply.
MRAM that uses magnetic properties to store data. This new type of chip will compete with other forms established forms of semiconductor memory, such as Flash and RAM.Most engineers believe that the technology, called MRAM could reduce the cost and power consumption of electronics for cell phones, music players, laptops, and servers. The feature that makes MRAM an alluring alternative to other forms of semiconductor memory is the way it stores data. Flash memory and RAM, for example,Hold information as electric charge. In contrast, MRAM uses the magnetic orientation Of electrons to represent bits. Hold data with out a power supply and can be written to and read from an unlimited number of times. Reading and writing data from MRAM is also fast, taking a matter of nanoseconds. MRAM is able to hold data without power.
Magnetoresistive Random Access Memory (MRAM)
• Why can’t your pc simply turn on like your television?
• MRAM uses magnetism rather than electrical power to store bits of data.
• No refresh is needed to retain the data.
• For users of laptops and other mobile devices, such as MP3 players and cell phones, MRAM is the holy grail of longer battery life.
Magnetic Core RAM
• The memory cells consist of wired threaded tiny ferrite rings (cores).
• X and Y lines to apply the magnetic filed.
• Sense/Inhibit line to ‘read’ the current pulse when the polarization of the magnetic field changes.
Giant Magnetoresistance (GMR)
Two thin films of altering ferromagnetic materials and a non-magnetic layer-spacer
Tunnel Magnetoresistance (TMR)
Two thin films of altering ferromagnetic materials and an insulating spacer.
Fe/MgO/Fe junctions reach over 200% decrease in electrical resistance at room temperature
In ferromagnetic metals electronic bands are exchange split which implies different densities of states at the Fermi energy for the up- and down-spin electrons.
• Spin of electrons is conserved in the tunneling process.
• Tunneling of up- and down-spin electrons are two independent processes → conductance occurs in the two independent spin channels.
• Electrons originating from one spin state of the first ferromagnetic film are accepted by unfilled states of the same spin of the second film.
Spin Valve GMR
• Hard layer: magnetization is fixed.
• Soft layer: magnetization is free to rotate.
• Thin non-ferromagnetic spacer ~3 nm.
• Spacer material Cu (copper) and ferromagnetic layers NiFe (permalloy).
• This configuration used in hard drives
Magnetic Tunnel Junction (MTJ)
MRAM: Fixed layer
MRAM: Reading process
MRAM: Writing process
Other RAM Technologies
MRAM Vs Other RAM Technologies
Future MRAM Improvements
Deepak Kumar rout
Dynamic random-access memory (DRAM) is a type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit. The capacitor can be either charged or discharged; these two states are taken to represent the two values of a bit, conventionally called 0 and 1
MRAM (magnetoresistive random access memory) is a method of storing data bits using magnetic charges instead of the electrical charges used by DRAM (dynamic random access memory).
HOW MRAM WORKS
Magnetoresistive Random Access Memory is a non-volatile computer memory (NVRAM)
1.By passing current the magnetic polarity is set to either 1 or 0. Information is then read by passing another current through the rail and measuring resistance
2..Because the spin state of the electron is stored magnetically, MRAM does not require a constant charge of electricity to maintain the polarity of each rail.
3..write capability does not degrade at nearly the rate of current solid-state flash technology.
1.Magnetoresistive random access memory (MRAM) uses the magnetic tunnel junction (MTJ) to store information
2. MRAM cell composed of a diode and an MTJ stack
3. MTJ stack consists of two ferromagnetic layers separated by a thin dielectric barrier
Comparison with other
The main determinant of a memory system's cost is the density of the components used to make it up. Smaller components, and fewer of them, mean that more "cells" can be packed onto a single chip, This improves yield, which is directly related to cost.
This demands a constant power supply, which is why DRAM loses its memory when power is turned off on the computer. As DRAM cells decrease in size, the refresh cycles become shorter, and the power draw more continuous.
In contrast, MRAM requires no refresh at any time. Not only does this mean it retains its memory with the power turned off, but also that there is no constant power draw.
DRAM performance is limited by the rate at which the charge stored in the cells can be drained (for reading) or stored (for writing)
MRAM operation is based on measuring voltages rather than charges or currents, so there is less "settling time" needed.
1.Aerospace and military systems
6.Cellular base stations
8.Battery-Backed SRAM replacement
9.Datalogging specialty memories (black box solutions)
Plz provide me with the full magnatoresistive ram(mram) full seminars report..