FM24C256 – Low power 256Kb FRAM with 2-wire serial interface


The FM24C256 is a 256-kilobit nonvolatile FRAM with an industry standard 2-wire serial interface that leverages the high-speed write capability of FRAM technology. 

A direct hardware replacement for equivalent EEPROMs, only better, the device reads and writes at bus speeds up to 1MHz and operates from a 5-volt power supply, drawing 75 micro amps for reads and 100 kHz for writes.  The FM24C256 is rated over the industrial temperature range (-40 degrees C to +85 degrees C) and is available in a green 8-pin EIAJ SOIC package.

FRAM offers three distinct benefits in advanced metering designs:

  • No Delay™ reads/writes:  FRAM writes data at bus speed, eliminating the need for a complicated data backup system in the event of power loss.
  • Virtually unlimited endurance:  FRAM collects data for an unlimited period without wearing out.  In an electric meter FRAM can be written every second for the life of a meter.  No other nonvolatile memory offers this capability.  Less advanced designs that exclude FRAM can only afford to write the data when power is failing because alternative memory products wear out quickly if they are written too often.
  • Low power consumption:  FRAM devices are RAMs and do not require charge pumps and are, therefore, orders of magnitude lower in power during write cycles than floating gate devices such as flash and EEPROM.  During battery-powered data collection, FRAM devices offer the lowest power operation of any memory solution available, making them ideal for a variety of data collection applications including water and gas meters.