The FM25L256B is a 256-kilobit (32K x 8) serial F-RAM memory employing an advanced ferroelectric process. A ferroelectric random access memory or F-RAM is nonvolatile and performs reads and writes similar to a RAM. It provides reliable data retention for 151 years while eliminating the complexities, overhead, and system-level reliability problems caused by serial Flash, EEPROM, and other nonvolatile memories. The FM25L256B device performs write operations at bus speed. No write delays are incurred. Data is written to the memory array immediately. By default, the FM25L256B is protected by a software write protection scheme. No complex device management is required.

Applications

• Data logging
• Metering
• Industrial control
• Medical devices

Features

• 256-Kbit Ferroelectric RAM (F-RAM)
• Organized as 32K x 8
• High-Endurance 100 Trillion (10<sup>14) Read/Writes
• 151-Year Data Retention
• NoDelay™ Writes
• Advanced High-Reliability Ferroelectric Process
• Fast Serial Peripheral Interface (SPI)
• Up to 40 MHz Bus Frequency
• Direct Hardware Replacement for Serial Flash and EEPROM
• Supports SPI Modes 0 (0,0) and 3 (1,1)
• Low Power Operation
• 2.0V to 3.6V Operating Voltage
• Industrial Temperature –40°C to +85°C
• 8-Pin SOIC, 8-Pin TSSOP, and 8-Pin DIP Packages
• RoHS Compliant

Benefits

• High endurance eliminates data loss concerns associated with EEPROM or Flash.
• Fast write speed allows for real-time data logging and eliminates write delays.
• Low power consumption reduces overall system power requirements.
• Simple SPI interface simplifies integration into existing systems.
• Wide operating voltage range provides flexibility in system design.

Additional Details

The FM25L256B uses an SPI bus for high-speed serial access. The SPI is a four-wire protocol consisting of a clock, data in, data out, and chip select signal. The device is designed to operate at a maximum bus frequency of 40 MHz. F-RAM memory combines the best attributes of RAM and ROM. It is nonvolatile like ROM and can retain data for over 151 years. F-RAM offers the same fast write times as RAM. This combination makes it ideal for applications requiring frequent or rapid writes.