Featured Videos

Your Innovation, Our Memory

Your Innovation, Our Memory

Emerging technologies require innovation on a whole new scale. See how we partner closely with our customers to gain unique insights about how we can optimize our memory solutions to enable your innovations—and help you change the world.

View video
Memory for Automotive

Memory for Automotive

Technology is reshaping the concept of driving. Automakers are developing countless new driver-assistance features and systems. See how Micron’s memory solutions are helping to enable these new supercomputing capabilities.

View video

About Micron

Where there's memory, there's Micron

Engineered for Innovation

For more than 30 years Micron has redefined innovation by designing, developing, and manufacturing some of the world’s most advanced technologies.

Learn more
Elpida is Now Micron

Elpida Is Now Micron

With the combined strength of our products, technology, and team members—our customers now have access to the broadest portfolio of best-in-class technology.

About the acquisition

Welcome to My Workspace!

Create an account to access these benefits:

  • Save part pages
  • Save Data Sheets and other files
  • Create folders to organize your projects
  • Share folders with colleagues
  • Organize secure documents for easy access
  • "Follow" parts to see alerts and updates

Learn more about Workspace features

Don't have an account yet? Sign up

Already have an account?   Login

My Folders

Your workspace is your area to organize and save part pages, data sheets, and links for easy access in the future. You can even start by saving some of the pages you've recently accessed below:

PSRAM/CellularRAM Standard Page Save
My Workspace

Merging the Best of DRAM and SRAM

CellularRAM® memory is a pseudo-static DRAM (PSRAM) device that features an SRAM-like architecture, hidden refresh operation, and SRAM pin-compatibility. This hybrid memory delivers the best of SRAM and DRAM features, combining low power consumption and high-speed read and write functions. Because CellularRAM memory also offers synchronous operations, fast access, and variable latency initial burst access, you get high throughput and excellent performance. It's an ideal solution for low-power, space-limited designs like MCPs, as well as mobile and industrial applications.

  • A range of densities, provides flexibility for many designs
  • Available in x16 word sizes with selectable bytes and burst lengths
  • A single device that can operate over an extended Vccq range
  • Offers extremely low power dissipation in standby and active modes; PAR in standby mode provides even greater power savings
  • Wide temperature ranges are ideal for rugged mobile and industrial environments
  • Perfect for space-limited mobile applications

Featured Article

What is CellularRAM?


Our CellularRAM memory is pseudo-static DRAM with an asynchronous/page and burst interface, hidden refresh operation, and SRAM pin compatibility, which makes it a convenient and effective solution, designed specifically for mobile applications.

Read More


An introduction to Micron® CellularRAM® and PSRAM Memory features and options.

Download Technical Note



For PSRAM CellularRAM (29)
Title & Description Secure ID# Updated Type
Industrial and Multimarket Application Memory Flyer: (PDF 398.61 KB) Our extensive and stable portfolio of IMM-focused memory solutions empower technology developments in automotive, industrial, medical, manufacturing, and other multimarket segments. 09/2014 Product Flyer
Hands-On Electronics Education: (PDF 1.05 MB)Read how Micron partnered with Digilent to develop inexpensive and yet powerful digital system design boards. 12/2009 Case Study
Row Boundary Crossing Functionality in CellularRAMâ„¢ Memory: (PDF 524.87 KB)Explains row boundary crossing in Micron CellularRAM memory devices TN-45-15 11/2009 Technical Note
Thinning Considerations for Wafer Products: (PDF 73.58 KB)Information on optimal wafer-thinning processes to meet specific customer requirements TN-00-19 10/2009 Technical Note
Burst A/D MUX CellularRAM Memory Flyer: (PDF 141.19 KB)Describes how reduced pin count CellularRAMâ„¢ memory can save design time and lower cost 08/2009 Product Flyer
CellularRAM PSRAM Flyer: (PDF 200.76 KB)Describes how CellularRAM PSRAM is an ideal, drop-in replacement for SRAM 08/2009 Product Flyer
CellularRAM Multiplexed Async/Burst Operation: (PDF 687.75 KB)Discusses multiplexing a non-multiplexed CellularRAM device at the substrate level TN-45-04 01/2009 Technical Note
PSRAM and CellularRAM Part Numbering System: (PDF 28.52 KB)Part numbering guide for Micron PSRAM and CellularRAM products. 12/2008 Part Numbering Guide
Connecting Micron CellularRAM Devices with the Atmel Microcontroller: (PDF 525.62 KB)Describes the preferred methods for connecting Micron CellularRAM devices to the Amtel microcontroller TN-45-33 06/2008 Technical Note
PSRAM 101: An Introduction to Micron CellularRAM and PSRAM: (PDF 351.24 KB)Demonstrates PSRAM and CellularRAM memory advantages over other memory options for use in mobile handsets; and presents available configurations TN-45-30 05/2008 Technical Note
Using Micron Asynchronous PSRAM with ADI ADSP-BF53x Blackfin Processors: (PDF 265.86 KB)Describes the design requirements for a seamless memory connection between Analog Devices Blackfin processors and Micron 70ns, 8Mb asynchronous PSRAM devices TN-45-27 06/2007 Technical Note
Using Micron Asynchronous PSRAM with the NXP LPC2292 and LPC2294 Microcontrollers: (PDF 255 KB)Describes the design requirements for a seamless memory connection between the NXP LPC2292 and LPC2294 family of microcontrollers and a Micron asynchronous PSRAM device TN-45-29 06/2007 Technical Note
Using CellularRAM Memory to Replace Single- and Dual-Chip Select SRAM: (PDF 179.87 KB)Discusses migrating a single- or dual-chip select SRAM design to Micron CellularRAM memory. Both hardware and software changes are covered. TN-45-17 01/2007 Technical Note
Implementing CellularRAM 2.0, x32 with Two CellularRAM 1.5 x16 Devices: (PDF 107.52 KB)Documents how the x32 CR2.0 memory interface can be emulated using a two-die stack of x16 CR 1.5 devices TN-45-07 12/2006 Technical Note
Fixed-Latency Operation in CellularRAM 1.0 Devices: (PDF 187.66 KB)Details how Micron has enhanced CellularRAM CR1.0 functionality TN-45-24 08/2006 Technical Note
Variable vs. Fixed Latency CellularRAM Operation: (PDF 122.39 KB)This technical note assists designers in understanding the differences between CellularRAM variable and fixed latency operations TN-45-22 07/2006 Technical Note
Using CellularRAM Memory on a NOR FLASH Bus: (PDF 391.96 KB)Discusses design considerations when placing a CellularRAM memory device on a NOR Flash bus TN-45-23 07/2006 Technical Note
Low-Power Options for Async/Page CellularRAM: (PDF 197.19 KB)Discusses the low-power options available to customers on async/page CellularRAM memory devices TN-45-20 05/2006 Technical Note
Using CellularRAM Memory to Replace NEC Mobile Specified RAM (PD46128512): (PDF 228.87 KB)Discusses migrating a 128Mb NEC Mobile Specified RAM design (PD46128512) to Micron 128Mb CellularRAM memory (MT45W8MW16B). Both hardware and software changes are covered. TN-45-18 03/2006 Technical Note
Using CellularRAM Memory to Replace Fujitsu 1.8V FCRAM: (PDF 208.91 KB)Discusses replacing Fujitsu 1.8V FCRAM with Micron CellularRAM memory TN-45-16 03/2006 Technical Note
Using CellularRAM Memory to Replace Fujitsu 3V FCRAM: (PDF 195.22 KB)Discusses replacing Fujitsu 3V FCRAM with Micron CellularRAM memory TN-45-14 02/2006 Technical Note
Using a Micron CellularRAM Device with the AMCC PPC405EZ Embedded Processor: (PDF 288.01 KB)Describes the design requirements for a seamless memory connection between the PPC405EZ and a Micron CellularRAM device TN-45-28 02/2006 Technical Note
Using CellularRAM Memory to Replace UtRAM : (PDF 195.88 KB)Assists migration from a 128Mb UtRAM design (K1B2816B6M) to Micron 128Mb CellularRAM memory (MT45W8MW16B). Both hardware and software changes are covered TN-45-13 01/2006 Technical Note
Density Migration for x16 Burst Multiplexed PSRAM Introduction: (PDF 65.9 KB)Discusses the design differences to account for when migrating a burst multiplexed device from 16Mb to 64Mb TN-45-06 01/2006 Technical Note
Designing Applications with the x16 Burst A/D Multiplexed Interface: (PDF 83.73 KB)Discusses the differences between a burst non-A/D MUX and burst A/D MUX device TN-45-10 11/2005 Technical Note
64Mb Burst CellularRAM P25A to P25Z Transition Guide: (PDF 64.45 KB)Discusses migrating a design based on the async/page/burst MT45W4MW16B (P25A) to MT45W4MW16BC (P25Z) TN-45-09 10/2005 Technical Note
64Mb Async/Page CellularRAM P25A to P25Z Transition Guide: (PDF 52.89 KB)Discusses migrating a design based on the async/page MT45W4MW16P (P25A) to the MT45W4MW16PC (P25Z) TN-45-08 10/2005 Technical Note
Functional Differences Between CellularRAM 1.0 and CellularRAM 1.5 : (PDF 141.07 KB)Discusses the functional difference between the CellularRAM 1.0 and CellularRAM 1.5 memory devices TN-45-01 08/2005 Technical Note
CellularRAM Asynchronous and Mixed-Mode Slow-Clock WRITE Concerns: (PDF 100.22 KB)Discusses the use of Micron CellularRAM-based devices in Mixed Mode operation and slow clock speeds TN-45-02 05/2005 Technical Note
For DRAM (15)
Title & Description Secure ID# Updated Type
HMC Part Numbering System: (PDF 59 KB)Part numbering guide for Hybrid Memory Cube 10/2014 Part Numbering Guide
DRAM Component Part Numbering System: (PDF 46.77 KB)Part numbering guide for DDR4/DDR3/DDR2/DDR/SDR SDRAM, Mobile LPDRAM, and RLDRAM components 10/2014 Part Numbering Guide
Legacy LPDRAM Part Numbering System: (PDF 114.47 KB)Part numbering guide for legacy LPDDR2 and LPDRR3 PoP and FBGA components 05/2014 Part Numbering Guide
SEMI Wafer Map Format: (PDF 114.26 KB)Micron has adopted the wafer map file format approved by Semiconductor Equipment and Materials International (SEMI). With SEMI formatting, Micron's customers can be confident they will always receive consistent, compatible, reliable map files. TN-00-21 03/2014 Technical Note
Routing Guidelines for Micron’s HMC-15G-SR: (PDF 3.3 MB)Provides sound methods, proven solutions, and detailed PCB layout guidelines to enable successful designs using Micron’s HMC. TN-43-03 HMC TN-43-03 06/2013 Technical Note
Recommended Soldering Parameters: (PDF 173.37 KB)Defines the recommended soldering techniques and parameters for Micron Technology, Inc., products. TN-00-15 12/2012 Technical Note
Bypass Capacitor Selection for High-Speed Designs: (PDF 481.9 KB)Describes bypass capacitor selection for high-speed designs. TN-00-06 03/2011 Technical Note
Micron Wire-Bonding Techniques: (PDF 66.13 KB)This technical note provides guidance on wire bonding techniques for both nickel-palladium (NiPd) and aluminum (Al) bond pads on Micron products. TN-00-22 11/2010 Technical Note
Uprating of Semiconductors for High-Temperature Applications: (PDF 428.33 KB)Describes the issues associated with temperature uprating and the risks involved in using components and/or systems outside the manufacturer's environmental specifications TN-00-18 05/2010 Technical Note
Accelerate Design Cycles with Simulation Models: (PDF 206.91 KB)Micron supplies the tools and guidelines necessary to verify new designs prior to layout. This technical note discusses software model support, signal integrity optimization, and logic circuit design. TN-00-09 02/2010 Technical Note
Understanding Signal Integrity: (PDF 1.64 MB)Describes how memory design, test, and verification tools can be used to the greatest advantage, from conception of a new product through end of life TN-00-20 12/2009 Technical Note
IBIS Behavioral Models: (PDF 163.98 KB)Micron has been a member of the IBIS Open Forum for many years and fully supports the IBIS specification. IBIS models for most Micron products are available for download from the Micron Web site. TN-00-07 11/2009 Technical Note
Understanding Quality and Reliability Requirements for Bare Die Applications: (PDF 142.04 KB)Describes the quality and reliability requirements for bare die applications TN-00-14 10/2009 Technical Note
FBGA Date Codes: (PDF 22.36 KB)Date codes for FBGA-packaged components 08/2005 Part Numbering Guide
FBGA Decoder: Micron's FBGA Part Marking Decoder makes it easier to understand part marking. Tool
For Products and Support (14)
Title & Description Secure ID# Updated Type
Micron Component and Module Packaging: (PDF 1.35 MB)Explanation of Micron packaging labels and procedures. CSN-16 11/2014 Customer Service Note
Product Marks/Product and Packaging Labels: (PDF 1.58 MB)Explains product part marking, and product and packaging labels. CSN-11 10/2014 Customer Service Note
Shipping Quantities: (PDF 1.22 MB)Provides standard part quantities for shipping. CSN-04 03/2014 Customer Service Note
RMA Procedures for Packaged Product and Bare Die Devices: (PDF 76.22 KB)Outlines standard returned material authorization (RMA) procedures, as well as the differences associated with bare die RMAs. CSN-07 01/2014 Customer Service Note
Wafer Packaging and Packaging Materials: (PDF 591.42 KB)Provides complete shipping and recycling information about each of the materials used for shipping Micron's products. CSN-20 11/2013 Customer Service Note
Thermal Applications: (PDF 246.79 KB)Describes some considerations in thermal applications for Micron memory devices TN-00-08 07/2013 Technical Note
Moisture Absorption in Plastic Packages: (PDF 97.08 KB)Describes shipping procedures for preventing memory devices from absorbing moisture and recommendations for baking devices exposed to excessive moisture TN-00-01 02/2013 Technical Note
Micron BGA Manufacturer's User Guide: (PDF 388.76 KB)Provides information to enable customers to easily integrate both leading-edge and legacy Micron's ball grid array (BGA) packages into their manufacturing processes. It is intended as a set of high-level guidelines and a reference manual describing typical package-related and manufacturing process-flow practices. CSN-33 12/2012 Customer Service Note
Electronic Data Interchange: (PDF 52.45 KB)Describes EDI transmission sets, protocol, and contacts. CSN-06 11/2012 Customer Service Note
PCN/EOL Systems: (PDF 79.21 KB)Explains Micron's product change notification and end-of-life systems. CSN-12 04/2012 Customer Service Note
Lead Frame Package User Guidelines: (PDF 245.66 KB)Discusses Micron's lead-frame package options CSN-30 05/2011 Customer Service Note
ESD Precautions for Die/Wafer Handling and Assembly: (PDF 120.81 KB)Describes the benefits of controlling ESD in the workplace, including higher yields and improved quality and reliability, resulting in reduced manufacturing costs. CSN-24 08/2010 Customer Service Note
Micron KGD Definitions: (PDF 65.52 KB)Describes the testing specifications and parameters for Micron's KGD-C1 and KGD-C2 DRAM die. CSN-22 07/2009 Customer Service Note
Bare Die SiPs and MCMs: (PDF 151.06 KB)Describes design considerations for bare die SiPs and MCMs. CSN-18 04/2009 Customer Service Note

Please Note: To view Secure Documents (Secure Lock) please log in or click on a secured document to request access.

PSRAM CellularRAM FAQs (5)

What densities and configurations of CellularRAM does Micron offer?
Micron offers 16Mb, 32Mb, 64Mb and 128Mb densities in the Async/Page and Async/Page/Burst configurations. Micron offers all densities of CellularRAM in wafer form as KGD (Known Good Die). In wafer form, Micron also offers the Burst A/D multiplexed configuration.
What is CellularRAM memory?
CellularRAM memory is a family of pseudo-SRAM (PSRAM) products that are backward compatible with 6T (six-transistor) SRAM and early generation Async or Page PSRAM. CellularRAM offers a complete new set of devices with innovative functionality burst, providing an evolutionary path to pseudo SRAM.
What are the target markets and applications for CellularRAM devices?
CellularRAM products target handsets, but can be used anywhere cache or buffered memory is required.
What are the benefits of CellularRAM technology?
CellularRAM technology's multiple benefits include:
  • backward compatibility with standard asynchronous SRAM devices
  • DRAM technology with an SRAM interface
  • higher densities and performance
  • lower cost per bit than current SRAM devices
What are the specific features that distinguish the CellularRAM family from existing SRAM architectures?
6T-SRAM is most commonly used in densities of 2/4/8Mb in cell phone designs. It features 70ns/85ns random cycle times with a bandwidth of ~30 MB/s in a x16 configuration. Active power consumption at 1.8V is 25mA. CellularRAM devices significantly exceed today’s low-power 6T-SRAM in density and bandwidth, while keeping active power consumption at equally low levels. CellularRAM products feature a random cycle time of 70ns at 1.8V, and allow a peak bandwidth of 208 MB/s in burst mode.


What is a "bank"?
A bank is an array of memory bits. Multiple arrays or banks are contained within a DRAM component. Depending on density, DRAM components may consist of 4 or 8 banks. For example, a bank may consist of 32 million rows, 4 bits across. This would equate to 128 megabits. Four of these banks in a single DRAM component would yield a 512Mb component.
What is the impedance tolerance of the driver in match-impedance mode relative to the expected value base on the perfect reference resistor connected to ZQ pin?
The impedance tolerance of the driver is ±15 percent.
Does thermal information change for IT parts?
Thermal information includes temperature limits and thermal impedance values. Temperature limits do change for IT parts (TC, TJ, and TA), but thermal impedance values (θJA, θJB, and θJC) do not because thermal impedance depends primarily on the package.
My design was based on a specification stating the JTAG was relative to VDD (1.8V), but now we’ve discovered that JTAG is actually relative to VDDQ (1.5V). It’s a fairly significant board spin to change this; what do I risk by leaving the design as-is? I assume that the specification is still for VDDQ + 0.3V = 1.8V, but with CMOS parts there’s no way I can guarantee that it won’t swing past that on transitions.
Your particular board design should not be a cause of major concern. The pins can handle the VDD voltage regardless of the VDDQ voltage.
Should the ECC memory chip share chip select and CKE signals with the other two main memory chips in our point-to-point application?
The ECC chip(s) should share the same CKE and CS# as the other devices because they are accessed as the same piece of data.
Is there a recommended lowest working frequency for SDRAM?
Because SDRAM does not have a DLL, there is no recommended lowest frequency. SDRAM parts will work at very low frequencies if all data sheet specifications are met. It is important to maintain a good slew rate, however, since a very slow slew rate will affect setup and hold-time transitions. Also, for operating frequencies of 45 MHz, tCKS = 3.0ns. For more information, see TN-48-09.
Can the SDRAM clock frequency be changed?
Micron SDRAM data sheets require that the clock frequency be constant during access or precharge states (READ, WRITE, tWR, and PRECHARGE commands). At other times frequency should not matter much because there is no DLL in SDRAM however, we do not recommend it. Lowering SDRAM frequency is OK even if you are not doing an LMR and CAS latency change. In case of increasing frequency, ensure tCK and CAS latency specifications are met. In either case, all other data sheet timing specifications should be adhered to.
Can CKE be tied HIGH throughout SDRAM operation (initialization and normal operation)?
JEDEC does not specify the exact state of CKE during initialization; it is supplier specific. Micron strongly recommends CKE be kept at an LVTTL logic LOW before applying a stable CLK signal. During normal operation, CKE can be tied HIGH. The initial LOW state of CKE prevents parts from receiving an illegal LMR command, which could put the part into an unknown or unexpected state.

Products and Support FAQs (1)

Who do I contact if I have questions about my buymicron.com order?
If you have any questions about your order, contact buymicron.com.

China and Storage: A View from the Huawei Cloud Congress, Shanghai

October 1, 2014 by Scott Shadley

Traveling around China this week and talking to customers, media, and industry experts was an eye-opener. The message that came through the loudest: enterprises in China are cost-conscious, but when the country's leading firms make investments in technology, they are willing to pay for performance and for a technological edge. This is particularly true when it comes to storage. The big change that I have noticed is that Chinese enterprises are no longer asking, “Do I need to be using SSDs...Read More

See all posts on DRAM, SSD, China

Latest Blog Posts

Speed Industrial Designs to Market Via Avnet SOC Board With Micron e·MMC

September 23, 2014 by Bryan Fletcher

By Guest Author Bryan Fletcher, Avnet In 2013, I was fortunate enough to help develop Avnet’s MicroZed system-on-module (SOM) board based on Xilinx’s Zynq™-7000 all-programmable sys...Read More

VSAN Demo 2014: A How-To Guide

September 17, 2014 by Jared Hulbert

Now that the team is back from VMWorld, we wanted to share the configuration for our VSAN demo that drew so much attention. This blog is intended to give you the high-level view of how we created the ...Read More