Fujitsu Semiconductor Ltd. is launching the 4 Mbit Resistive random access memory (ReRAM) MB85AS4MT, the world's largest density mass-produced ReRAM product, optimal for wearable devices and hearing aids. This is the first ReRAM product to be jointly developed with Panasonic Semiconductor Solutions Co., Ltd.

The MB85AS4MT is an SPI-interface ReRAM product that operates with a wide range of power supply voltage, from 1.65V to 3.6V. It features an extremely small average current in read operations of 0.2mA at a maximum operating frequency of 5MHz.

It is optimal for battery operated wearable devices and medical devices such as hearing aids, which require high density, low power consumption electronic components.

Until now, Fujitsu Semiconductor has been producing FRAM products, which have greater performance than conventional non-volatile memory, such as EEPROM and serial flash memory. FRAM offers high read/write endurance and low power consumption.

Resistive random access memory is a form of non-volatile memory in which a pulse voltage is applied to a metal oxide thin film, creating massive changes in resistance to record ones and zeros. With a simple structure of metal oxide placed between electrodes, the manufacturing process is very simple, while still offering such excellent features as low power consumption and fast write. Panasonic Semiconductor Solutions Co., Ltd. began mass-production of microcomputers with ReRAM in 2013.

The newly developed ReRAM features the ability to operate with a wide range of power supply voltage, from 1.65V to 3.6V, can be operated at a maximum of 5MHz through an SPI interface, and uses extremely small average current during read operations (0.2mA operating at 5MHz). It offers the industry's lowest power consumption for read operations in non-volatile memory.

The package is a 209mil 8 pin small outline package (SOP), pin-compatible with other non-volatile memory products such as EEPROM. Fujitsu Semiconductor has mounted a 4 Mbit memory density, exceeding the maximum density of serial interface EEPROM, in a miniature 8-pin SOP package size.

Main Specifications

• Product Part Number: MB85AS4MT
• Memory Density (configuration): 4 Mbit (512K words x 8 bits)
• Interface: Serial peripheral interface (SPI)
• Operating power supply voltage: 1.65V - 3.6V
• Low power consumption:
  • Read operating current: 0.2mA (at 5MHz)
  • Write operating current: 1.3mA (during write cycle time)
• Standby current: 10µA
• Sleep current: 2µA
• Guaranteed write cycles: 1.2 million cycles
• Guaranteed read cycles: Unlimited
• Write cycle time (256 byte page): 16ms (with 100% data inversion)
• Data retention: 10 years (up to 85°C)
• Package: 209mil 8-pin SOP