The memory cell is based on a transition metal oxide sandwich. The manufacturing details of the latest ReRAM were not disclosed but Panasonic has worked with tantalum oxide in the past.
The MB85AS8MT is an EEPROM-compatible non-volatile memory with SPI-interface that operates over a power supply range from 1.6V to 3.6V. A major feature is the small average read current. At an operating frequency of 5MHz, the average read current is 0.15mA, which is 5 percent of large density EEPROM devices. This enables low battery consumption when mounted in applications with frequent data-read operations. The device has a maximum operating frequency of 10MHz.
The package is an EEPROM-compatible 8-pin small outline package (SOP). In addition, a very small 11-pin WL-CSP package of 2mm x 3mm is available for mounting in small wearable devices.
Panasonic was the first company into mass production with ReRAM technology. It has been shipping a microcontroller with ReRAM on-chip since 2012 reportedly based on a 180nm process technology. The Panasonic MN101L microcontroller includes 64kbytes of ReRAM on-chip. Panasonic has also claimed to have evaluated a 40nm memory array.
In 2016 Panasonic partnered with Fujitsu Semiconductor Ltd. to make a discrete 4Mbit ReRAM (see Discrete ReRAM goes into mass production). The process geometry was not revealed but given the memory capacity that is also likely to be based on a mature process such as 180nm.
Fujitsu portrays the ReRAM as complementary to ferroelectric RAM (FRAM) which offer higher write endurance and faster write speeds compared to EEPROM and flash memory. FRAM is well suited to datalogging and frequent write outs for data protection against loss of power.
The ReRAM is better suited to situations where there is limited data written out but frequent reads, Fujitsu said.
Related links and articles: