Preliminary
FM24W256
256Kb Wide Voltage Serial F-RAM
Features
256K bit Ferroelectric Nonvolatile RAM
Organized as 32,768 x 8 bits
High Endurance 100 Trillion (10
14
) Read/Writes
38 year Data Retention (
@
+75ºC)
NoDelay™ Writes
Advanced High-Reliability Ferroelectric Process
Fast Two-wire Serial Interface
Up to 1 MHz maximum bus frequency
Direct hardware replacement for EEPROM
Supports legacy timing for 100 kHz & 400 kHz
Low Power Operation
Wide Voltage Operation 2.7V-5.5V
100
A
Active Current (100 kHz)
15
A
Standby Current (typ.)
Industry Standard Configuration
Industrial Temperature -40 C to +85 C
8-pin “Green”/RoHS SOIC Packages
Description
The FM24W256 is a 256-kilobit nonvolatile memory
employing an advanced ferroelectric process. A
ferroelectric random access memory or F-RAM is
nonvolatile and performs reads and writes like a
RAM. It provides reliable data retention for 10 years
while eliminating the complexities, overhead, and
system level reliability problems caused by
EEPROM and other nonvolatile memories.
The FM24W256 performs write operations at bus
speed. No write delays are incurred. Data is written to
the memory array immediately after it has been
successfully transferred to the device. The next bus
cycle may commence immediately without the need
for data polling. In addition, the product offers
substantial write endurance compared with other
nonvolatile memories. The FM24W256 is capable of
supporting 10
14
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 collection
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 EEPROM, yet these benefits are
available in a hardware drop-in replacement. The
FM24W256 is available in industry standard 8-pin
SOIC package using a familiar two-wire protocol. It
is guaranteed over an industrial temperature range of
-40°C to +85°C.
This is a product that has fixed target specifications but are subject
to change pending characterization results.
Pin Configuration
A0
A1
A2
VSS
1
2
3
4
8
7
6
5
VDD
WP
SCL
SDA
Pin Names
A0-A2
SDA
SCL
WP
VSS
VDD
Function
Device Select Address
Serial Data/Address
Serial Clock
Write Protect
Ground
Supply Voltage
Ordering Information
FM24W256-G
FM24W256-GTR
FM24W256-EG*
FM24W256-EGTR*
8-pin “Green”/RoHS SOIC
8-pin “Green”/RoHS SOIC, Tape
& Reel
8-pin “Green”/RoHS EIAJ SOIC
8-pin “Green”/RoHS EIAJ SOIC,
Tape & Reel
* Not Recommended for New Designs
Ramtron International Corporation
1850 Ramtron Drive, Colorado Springs, CO 80921
(800) 545-FRAM, (719) 481-7000
Rev. 1.3
July 2011
Page 1 of 13
RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
