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FM24W256: 256-Kbit (32 K × 8) Serial (I2C) F-RAM Datasheet | Cypress Semiconductor

FM24W256: 256-Kbit (32 K × 8) Serial (I2C) F-RAM Datasheet

Last Updated: 
Oct 26, 2015


  • 256-Kbit ferroelectric random access memory (F-RAM) logically organized as 32 K × 8
    • High-endurance 100 trillion (1014) read/writes
    • 151-year data retention (See the Data Retention and Endurance table)
    • NoDelay™ writes
    • Advanced high-reliability ferroelectric process
  • Fast 2-wire Serial interface (I2C)
    • Up to 1-MHz frequency
    • Direct hardware replacement for serial (I2C) EEPROM
    • Supports legacy timings for 100 kHz and 400 kHz
  • Low power consumption
    • 100 μA active current at 100 kHz
    • 15 μA (typ) standby current
  • Wide voltage operation: VDD = 2.7 V to 5.5 V
  • Industrial temperature: –40 °C to +85 °C
  • 8-pin small outline integrated circuit (SOIC) package
  • Restriction of hazardous substances (RoHS) compliant

Functional Overview

The FM24W256 is a 256-Kbit nonvolatile 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 EEPROM and other nonvolatile memories.

Unlike EEPROM, the FM24W256 performs write operations at bus speed. No write delays are incurred. Data is written to the memory array immediately after each byte is successfully transferred to the device. The next bus cycle can commence without the need for data polling. In addition, the product offers substantial write endurance compared with other nonvolatile memories. Also, F-RAM exhibits much lower power during writes than EEPROM since write operations do not require an internally elevated power supply voltage for write circuits. The FM24W256 is capable of supporting 1014 read/write cycles, or 100 million times more write cycles than EEPROM.

These capabilities make the FM24W256 ideal for nonvolatile memory applications, requiring frequent or rapid writes. Examples range from data logging, where the number of write cycles may be critical, to demanding industrial controls where the long write time of EEPROM can cause data loss. The combination of features allows more frequent data writing with less overhead for the system.

The FM24W256 provides substantial benefits to users of serial (I2C) EEPROM as a hardware drop-in replacement. The device specifications are guaranteed over an industrial temperature range of –40 °C to +85 °C.