Fujitsu Launches 12Mbit ReRAM – Largest Memory Density in ReRAM Family

- Non-volatile Memory IC Capable of Storing Character Data for Approximately 90 Newspaper Pages in Very Small Package -


Fujitsu Semiconductor Memory Solution Limited announced the launch of a 12Mbit ReRAM (Resistive Random Access Memory)(*1), MB85AS12MT, which is the largest density in Fujitsu’s ReRAM product family(*2). Evaluation samples are currently available. (Fig.1)

This new product is a non-volatile memory having a large memory density of 12Mbit in a very small package size of approximately 2mm x 3mm. It has an outstandingly low level of read current of 0.15mA on average during read operations. With features of small package size and small read current, this product is ideal for use in wearable devices such as hearing aids and smart watches. (Fig.2)

Fig.1:MB85AS12MT Packages (Top and Bottom)
Fig.2:Examples of ReRAM Usage


The MB85AS12MT is a non-volatile memory with 12Mbit memory density and operates at a wide range of power supply voltage from 1.6V to 3.6V. The new ReRAM product’s memory density is 1.5 times larger than the existing 8Mbit ReRAM while keeping the same package size, WL-CSP (Wafer Level Chip Size Package), with the same pin assignment. The product can store character data for approximately 90 pages of newspaper (*3) in a small package size of about 2mm x 3mm.

The WL-CSP used for the MB85AS12MT can save approximately 80% of its mounted surface area compared with 8-pin SOP that is frequently used for memory devices with the Serial Peripheral Interface (SPI). (Fig.3)

Fig.3:Mounting Area Comparison

The new ReRAM product features an extremely smaller read current level than other non-volatile memories. At an operating frequency of 5MHz, the average read current is as small as 0.15mA and even the maximum read current is 1.0mA at 10MHz operation. Therefore, battery consumption can be minimized by mounting the MB85AS12MT in battery-operated devices with frequent data-read operations, such as specific program reading or setting data reading. It is ideal for use in battery-operated small wearable devices such as hearing aids and smart watches.

Using the above features, the ReRAM product can solve the following issues arising from the use of flash memory or EEPROM in the development of wearable devices. (Fig.4)

Fig.4:Customers’ Issues and Solutions

Case 1

  • Issue: Insufficient memory density of 8Mbit ReRAM
  • Solution: Use 12Mbit ReRAM with the same pin assignment as 8Mbit product.
  • Benefit: Enhancing performance of end-products

Case 2

  • Issue: Need to keep a package size small due to restriction of mounting area
  • Solution: Use 12Mbit ReRAM in a very small package.
  • Benefit: Maintaining small size while enhancing performance

Case 3

  • Issue: Difficult to reduce power consumption by conventional non-volatile memory
  • Solution: Use ReRAM featuring very small read current.
  • Benefit: Extending battery life in end-products (less battery replacement)

While continuing to pursue larger-density FeRAM (*4) products for customers’ devices requiring frequent data rewriting, Fujitsu Semiconductor Memory Solution has been developing new non-volatile memories to meet the requirement of frequent data read-out, which leads to introducing this new 12Mbit ReRAM product.

Fujitsu Semiconductor Memory Solution continues to develop various low-power memory products to meet customers’ requirements.

Key Specifications

Part numberMB85AS12MT
Density (configuration)12Mbit (1.5M x 8bit)
InterfaceSPI interface
Operating voltage1.6V to 3.6V
Operating temperature range-40°C to +85°C
Read enduranceUnlimited
Write endurance500,000 times
Package11-pin WL-CSP
Low power consumptionRead current: 0.15mA (Ave.) at 5MHz operation
Read current: 1.0mA (Max.) at 10MHz operation
Write current: 2.5mA (Max.) at 10MHz operation
Sleep current: 8μA (Max.)

Glossary and Notes

  • *1:
    Resistive Random Access Memory. A form of non-volatile memory in which pulse voltage is applied to a thin metal oxide film, creating massive changes in resistance to record ones and zeros. With a simple structure of metal oxide placed between electrodes, its manufacturing process is very simple, while still offering excellent features such as low power consumption and fast write speed.
  • *2:
    The ReRAM product was jointly developed with Nuvoton Technology Corporation Japan (former Panasonic Semiconductor Solutions Co., Ltd.).
  • *3:
    Assuming newspapers issued in Japan
  • *4:
    Ferroelectric Random Access Memory. A type of memory that uses a ferroelectric file as capacitors that store data. Retains contents even when power is removed. Combines benefits of both ROM and RAM, with fast write speed, low power consumption, and high read/write cycle endurance. Produced by Fujitsu Semiconductor Memory Solution since 1999.


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