Preliminary
FM25W256
256Kb Wide Voltage SPI 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
Very Fast Serial Peripheral Interface - SPI
•
Up to 20 MHz Frequency
•
Direct Hardware Replacement for EEPROM
•
SPI Mode 0 & 3 (CPOL, CPHA=0,0 & 1,1)
Write Protection Scheme
•
Hardware Protection
•
Software Protection
Low Power Operation
•
Wide Voltage Operation 2.7V – 5.5V
•
15 µA (typ.) Standby Current
Industry Standard Configurations
•
Industrial Temperature -40°C to +85°C
•
8-pin “Green”/RoHS SOIC (-G)
Description
The FM25W256 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 FM25W256 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 FM25W256 is capable of
supporting 10
14
read/write cycles, or 100 million
times more write cycles than EEPROM.
These capabilities make the FM25W256 ideal for
nonvolatile memory applications requiring frequent
or rapid writes or low power operation. 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 FM25W256 provides substantial benefits to
users of serial EEPROM as a hardware drop-in
replacement. The FM25W256 uses the high-speed
SPI bus, which enhances the high-speed write
capability
of
F-RAM
technology.
Device
specifications are guaranteed over an industrial
temperature range of -40°C to +85°C.
Pin Configuration
CS
SO
WP
VSS
1
2
3
4
8
7
6
5
VDD
HOLD
SCK
SI
Pin Name
/CS
/WP
/HOLD
SCK
SI
SO
VDD
VSS
Function
Chip Select
Write Protect
Hold
Serial Clock
Serial Data Input
Serial Data Output
Supply Voltage (2.7 to 5.5V)
Ground
Ordering Information
FM25W256-G
FM25W256-GTR
“Green”/RoHS 8-pin SOIC
“Green”/RoHS 8-pin SOIC,
Tape & Reel
This is a product that has fixed target specifications but are subject
to change pending characterization results.
Rev. 1.3
Feb. 2011
Ramtron International Corporation
1850 Ramtron Drive, Colorado Springs, CO 80921
(800) 545-FRAM, (719) 481-7000
http://www.ramtron.com
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RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
