Introduction to MRAM and its Applications

TM

Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2006. 1

Introduction to MRAM and its Applications

TMFreescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2006. 2

Non-volatile memory with unlimited read-write endurance

Non-destructive read/write Symmetrical 35ns Read/Write access time Bitwise erasable (28 Mb/s) Data Retention >10 Years 256Kx16bit organization 3.3V single power supply Fast SRAM compatible pinout (center power and

ground) Commercial Temperature (0-70°C) RoHS Compliant TSOP type-II package Flexible Data Bus (8/16-bit access) LVI prevents writes on power loss I/O TTL compatible Fully static operation

Industry First - Freescale’s 4Mb MRAM

MR2A16A

General Specification


MRAM Advantages

Data Retention - > 10 years

Stable & Reliable - Data stored by polarization not charge

Symmetrical Read/WriteByte writeable – bit level granularity

35ns for 4Mb at 0.18um technology node

Unlimited Endurance - 1016

Non-destructive read – no wearout, no leakage, no soft errors

• Integrated with Existing CMOS Baseline• Compatible with Embedded Designs

• Highly Reliable

Nonvolatile

Fast

Unlimited Cycles

Viable


MRAM Endurance Cycling

0%

100%

1 100 10000 1000000 1E+08 1E+10 1E+12 1E+14

Number of Read/Write Cycles

Pas

sin

g %

Reliability Leadership

Endurance cycling has reached 58 trillion cycles with no change in critical parameters.

Data from >2800 bits from 900 devices 8 orders of magnitude more cycles than current Flash technologyNo known failure modes are seen or expected.

Flash Capability


MRAM Product Roadmap

2006 2007

1Mb,35nS48-pin TSSOP

0-70C

Available Now

Coming Soon

Proposed

8/16M,35Ns119PBGA-40-105C

MR2A16A4Mb,35nS

44-pin TSOP0-70C

MR2A16A4Mb,35nS

44-pin TSOP-40-105C

1Mb-40-105C

16Mb

8Mb

4Mb

1Mb512Kb/256Kb

1/4Mb0-70CBGA

July 2007

2008+


MRAM Basics


Information is stored as magnetic polarization, not charge

The state of the bit is detected as a change in resistance

How MRAM Works

Magnetic layer 1 (free layer)

Magnetic layer 2 (fixed layer)

Tunnel barrier

Magnetic vectors are parallel – low resistance. “0”

Magnetic vectors are anti-parallel – high resistance. “1”

S

S N

N N

S N

S


1 T-1 MTJ MRAM memory cell operation - read

Isolation Transistor“ON”

Read Mode

ISense

To read an MRAM bit, current is passed through the bit and the resistance of the bit is sensed.


1 T-1 MTJ MRAM memory cell operation - write

Free LayerTunnel Barrier

Fixed Layer

Easy Axis Field

Hard Axis Field

Isolation Transistor“OFF”

“Write Mode”

IEasy

IHard

To write an MRAM bit, current is passed through the programming lines generating magnetic fields.

The sum of the magnetic field from both lines is needed to program the bit.

No moving parts.


4Mb Memory Cell

M5-BLVia1-4M1-3

N+P-

Layer Name

N+ N+

M4-DL MVia BE TVia TETJ

N+ N+N+ N+

M1

M3

M2

M4-DL

V1

V2

V3

V4MVia

BE

TETJ TVia

M5-BL

Group SelectPass Xtor Pass XtorThk Oxide Xtor

i

i

Program path for Writing information

Sense Path for bit cell reading


Freescale……. Technology Leadership

MRAM BEOL

CMOS FEOL

Contact

Via 1

Metal 2

Metal 1

Via 2

Metal 4

Bit cell

Via 3

Metal 5

Metal 3MTJ

Metal 4

Metal 5

MRAM module


MRAM – Functional Operation


Toggle Bit Technology


Bit Line

DL Program Line

BL Program Line

Free Tri-Layer

Tunnel Barrier

Pinning Layer

Bit Line

Program Line 1

Program Line 2

Free Tri-Layer

Tunnel Barrier

Pinned Ferromagnetic

Pinning Layer

Ferromagnetic layerCoupling LayerFerromagnetic layer

Toggle MRAM Bit Cell


H=0H=0

Conventional Free Layer

Tri-Layer Coupled Free Layer

H=0

Free Layer Field Response


Elements of Toggle Bit

Balanced SAF free-layerBit oriented 45º to linesUnipolar currentsOverlapping pulse sequencePre-read / decision write Write

Line 1(H1)

WriteLine 2(H2)

HardAxis

EasyAxis


HardAxisHardAxisHardAxis

EasyAxisEasyAxisEasyAxis

Write Line 2

Write Line 1



Write Line 2

Write Line 1



Write Line 2



Write Line 2



Write Line 2

Write Line 1

Write Line 1

Write Line 2

t0 t1 t2 t3 t4

Off

On

Off

On

H 1

I 1

H 2

I 2

H 1

I 1

H 2

I 2

Write Line 1

Write Line 1

Toggle MRAM Switching Sequence


Competition, Applications & Product Timeline


Initial Competitive Markets for MRAM

Competition is limited to those memory technologies that have the same attributes of MRAM:

• Non-volatility• High Read/Write Performance • High Read/Write Endurance

SRAM – Not non-volatileDRAM – Not non-volatileFlash – Low write performance, poor enduranceFeRAM – Limited performance, limited enduranceBBSRAM – Functionally compatible


MR2A16ATS35C Key Features

►Key Features• High performance – symmetrical read and write timing• Small size and scalable for future technologies• Nonvolatile with virtually unlimited read-write endurance• Low leakage and low voltage capable

MRAM SRAM DRAM Flash FeRam

Read Speed Fast Fastest Medium Fast Fast

Write Speed Fast Fastest Medium Low Medium

Array Efficiency Med/High High High Med/Low Medium

Future Scalability Good Good Limited Limited Limited

Cell Density Med/High Low High Medium Medium

Non-Volatility Yes No No Yes Yes

Endurance Infinite Infinite Infinite Limited Limited

Cell Leakage Low Low/High High Low Low

Low Voltage Yes Yes Limited Limited Limited

Complexity Medium Low Medium Medium Medium


Competitive Devices

Supplier TechnologyPart Number Density Speed

Freescale MRAM MR2A16ATS35C 4Mb 35ns

Ramtron FRAM FM20L08-60-TGC 1Mb 350ns

STM BBSRAM M48Z512AY-70PM1 4Mb 70nsBBSRAM M48Z512AY-70PM1 4Mb 70nsBBSRAM 497-2886-5-ND 4Mb 70nsBBSRAM 497-2886-5-ND 4Mb 70ns

Maxim (Dallas) BBSRAM DS1250AB-100+ 4Mb 100nsBBSRAM DS1250AB-100+ 4Mb 100nsBBSRAM DS1250AB-70+ 4Mb 70nsBBSRAM DS1250AB-70+ 4Mb 70ns

SimTek nvSRAM STK17TA8-R35I (Industrial) 1Mb 35nsnvSRAM STK17TA8-RF25 (Commercial) 1Mb 25nsnvSRAM STK17TA8-RF35 (Commercial) 1Mb 35nsnvSRAM STK17TA8-RF45 (Commercial) 1Mb 45nsnvSRAM STK17TA8-RF45I (Industrial) 1Mb 45ns

Texas Instr BBSRAM BQ4013Y (Commercial) 1Mb 70nsBBSRAM BQ4013YMA (Commercial) 1Mb 120ns


MR2A16ATS35C Competitive Analysis

Supplier TechnologyPart Number Density Config Speed Read Current Temperature Qty Price

Freescale MRAM MR2A16A 4Mb 256Kbx16 35ns 55 mA 0 to 70C 1000 22.50$

Ramtron FRAM FM20L08-60-TGC 1Mb 128Kbx8 350ns 22 mA -40C to 85C small 17.83$

STM BBSRAM M48Z512AY-70PM1 4Mb 512Kx8 70ns 115 mA 0 to 70C small 70.00$ BBSRAM 497-2886-5-ND 4Mb 512Kx8 70ns 115 mA 0 to 70C 5000 42.00$

Maxim (Dallas)BBSRAM DS1250AB-100+ 4Mb 512Kx8 100ns 85 mA -40C to 85C 100 52.34$ BBSRAM DS1250AB-100+ 4Mb 512Kx8 100ns 85 mA -40C to 85C 1000 48.15$ BBSRAM DS1250AB-70+ 4Mb 512Kx8 70ns 85 mA -40C to 85C 100 52.85$ BBSRAM DS1250AB-70+ 4Mb 512Kx8 70ns 85 mA -40C to 85C 1000 48.63$

SimTek nvSRAM STK14CA8-RF25I 1Mb 128Kbx8 25ns 70 mA -40C to 85C small $24.72nvSRAM STK14CA8-RF45I 1Mb 128Kbx8 45ns 55 mA -40C to 85C small $20.64nvSRAM STK14CA8-RF45 1Mb 128Kbx8 45ns 55 mA 0C to 70C small $17.19


MCU

SRAM

BatteryControl Chip

CE

Problems• System design complexity• Board space and weight• Battery life• Manufacturing complexity• Environmental concerns MRAM

Solutions• Single chip solution• Simple, low cost system design• Manufacturing simplification• No battery• Unlimited life• Smaller profile • Higher performance• Environmentally friendly

“Built-in-house” Components

MCUSRAM

Battery

Problems• Cost• Manufacturing complexity• Battery life• Low performance• Environmental concerns

“Off-the-shelf” components

Addr/Data Bus

Sample Application – Battery Backed SRAM Replacement

Addr/Data Bus

Addr/Data Bus MCU


Target Application – Battery Backed SRAM Replacement

Primary Usage• Data Logging• Parameter Storage• System Status• Storage Buffers

• Battery Contact Failure

• Out-of-Tolerance Voltage Spikes

• Limited Life

Manufacturing Complexity

More Parts & Labor & Board Space & Weight

System Design Complexity


Standalone Market Example: RAID Storage

The Application• Redundant array of inexpensive disks (RAID 0-7 & Hybrids)• RAID systems are found in imaging, video, audio, web sites, emerging multimedia programs,

transaction processing systems, mission critical backup solutions for hospitals, police, banking and insurance firms have ever increasing needs for high transfer rates and storage capacity.

MRAM Improves Performance• Non volatile memory increases security & integrity

of data• Failsafe RAID cache• High data availability without BBSRAM (Battery-

Backed Static RAM) difficulties

Critical Cache

Configuration Data

RAID Journal

RAID Controller

Chip

DiskArrays

RAID Controller


MR2A16ATS35C Application Spaces►Target Application Spaces

• Data Streaming RAID systems and servers POS terminals Data-acquisition systems Data logging Buffers Routers / switches Printers / copiers

• System Configuration Black-box applications Gaming System status ►Currently not targeting high density, space-

constrained applications• Portable digital audio players• Jump drives• Digital camera data storage


Embedded MRAM Example: System on a Chip


MRAM Compared to Flash


Sample and Production Timing

Current planning:

Now – 4Mb Qualification Samples. 0 – 70C, 35ns

Now – 4Mb Production. 0 – 70C, 35ns

1Q07 – 4Mb Qualification Samples. -40C – 105C

2Q07 – 4Mb Production Volumes. -40C – 105C

2007 – Derivative Products (to be announced)


Summary

Industry’s first high performance, reliable non volatile memory technology.

4Mb part is available now for applications like configuration storage, data logging, cache buffer, etc.

Industrial temperature part (-40C to 105C) will be available by mid-2007.

Various standalone parts will be available from Freescale.

Embedded designs are being defined.

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Introduction to MRAM and its Applications

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