FM24C256
256Kb FRAM Serial Memory
Features
256Kbit Ferroelectric Nonvolatile RAM
• Organized as 32,768 x 8 bits
• High Endurance 10 Billion (1010) Read/Writes
• 45 year Data Retention
• NoDelay™ Writes
• Advanced High-Reliability Ferroelectric Process
Fast Two-wire Serial Interface
• Up to 1 MHz Maximum Bus Frequency
• Supports Legacy Timing for 100 kHz & 400 kHz
Description
The FM24C256 is a 256-kilobit nonvolatile memory
employing an advanced ferroelectric process. A
ferroelectric random access memory or FRAM is
nonvolatile and performs reads and writes like a
RAM. It provides reliable data retention for 45 years
while eliminating the complexities, overhead, and
system level reliability problems caused by
EEPROM and other nonvolatile memories.
The FM24C256 performs write operations at bus
speed. No write delays are incurred. The next bus
cycle may commence immediately without the need
for data polling. In addition, the product offers write
endurance orders of magnitude higher than
EEPROM. Also, FRAM exhibits much lower power
during writes than EEPROM since write operations
do not require an internally elevated power supply
voltage for write circuits.
These capabilities make the FM24C256 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.
Low Power Operation
• 5V Operation
• 200 µA Active Current (100 kHz)
• 100 µA Standby Current
Industry Standard Configuration
• Industrial Temperature -40° C to +85° C
• 8-pin EIAJ SOIC
• “Green” Packaging Option
Pin Configuration
A0
A1
A2
VSS
Pin Names
A0-A2
SDA
SCL
WP
VSS
VDD
1
2
7
3
6
4
VDD
WP
SCL
SDA
8
5
Function
Device Select Address
Serial Data/Address
Serial Clock
Write Protect
Ground
Supply Voltage 5V
Ordering Information
FM24C256-SE
8-pin EIAJ SOIC
FM24C256-G
“Green” 8-pin EIAJ SOIC
NOTE: Top side part marking is “FM24C256-S”
whereas “FM24C256-SE” is used only for ordering.
The FM24C256 is available in a 8-pin EIAJ SOIC
package using an industry standard two-wire
protocol. Specifications are guaranteed over an
industrial temperature range of -40°C to +85°C.
This product conforms specifications per the terms of the Ramtron
standard warranty. The product has completed Ramtron’s internal
qualification testing and has reached production status.
Ramtron International Corporation
1850 Ramtron Drive, Colorado Springs, CO 80921
(800) 545-FRAM, (719) 481-7000
www.ramtron.com
Rev 3.1
May 2005
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