Fujitsu Semiconductor has developed SPI (serial peripheral interface) FRAMs (ferroelectric RAMs) based on the 0.18µm technology. FRAM combines the advantages of swift writing SRAM with non-volatile flash. The MB85RSxxx SPI FRAM family comprises three devices, namely MB85RS256A, MB85RS128A and MB85RS64A that have density levels of 256, 128, and 64kbit respectively. The FRAMs operate at a voltage range between 3 and 3.6V and provide 10billion write and read cycles. They also have a data retention of 10 years at 55°C. The company has also increased the operating frequency to a maximum of 25MHz. Since the FRAM do not use voltage boosters for the writing process, they are suitable for low power applications. The FRAMs are offered in 8pin plastic, small outline packages with standard memory pin assignment, which are compatible with E2PROM devices. The company also offers FRAM standalone devices with I²C as well as parallel interfaces. The density levels of the memories vary from 16kbit to 4Mbit. They are used in metering, factory automation applications as well as various industrial segments, where data logging, high speed write access and high endurance is essential.
